Develop Reference

Create Round Button with Border IN UWP Windows 10 C#

I am trying to create a round button, with a White Border and a Transparent Background (as the old AppBarButtons in Windows 8.1) in UWP Windows 10.
I have found several samples like these:
https://comentsys.wordpress.com/2015/05/23/windows-10-universal-windows-platform-custom-button/
https://social.msdn.microsoft.com/Forums/sqlserver/en-US/cda7a526-5e99-4d4a-a73c-0be4ce77f961/uwpwindows10-how-to-make-button-with-round-edges?forum=wpdevelop&prof=required
But the problem is with the Border.
When I setting the BorderBrush to a certain color, it turns out the Border is for Button's "Rectangle".
Is there a way I can create a Round border for a button?

Are you looking for something like this?
<StackPanel>
<Button Background="Transparent">
<StackPanel>
<Border CornerRadius="10"
Background="Transparent"
BorderBrush="White"
BorderThickness="3">
<TextBlock Text="MyButton"
Margin="10"
Foreground="White"/>
</Border>
</StackPanel>
</Button>
</StackPanel>

There are few ways to achieve this, one by using a style can look like this - remove BorderBrush from ContentPresenter and add an Ellipse with that brush. Sample in XAML:
<Page.Resources>
<Style x:Key="CircleButtonStyle" TargetType="Button">
<Setter Property="Background" Value="{ThemeResource SystemControlBackgroundBaseLowBrush}"/>
<Setter Property="Foreground" Value="{ThemeResource SystemControlForegroundBaseHighBrush}"/>
<Setter Property="BorderBrush" Value="{ThemeResource SystemControlForegroundTransparentBrush}"/>
<Setter Property="BorderThickness" Value="{ThemeResource ButtonBorderThemeThickness}"/>
<Setter Property="Padding" Value="8,4,8,4"/>
<Setter Property="HorizontalAlignment" Value="Left"/>
<Setter Property="VerticalAlignment" Value="Center"/>
<Setter Property="FontFamily" Value="{ThemeResource ContentControlThemeFontFamily}"/>
<Setter Property="FontWeight" Value="Normal"/>
<Setter Property="FontSize" Value="{ThemeResource ControlContentThemeFontSize}"/>
<Setter Property="UseSystemFocusVisuals" Value="True"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="Button">
<Grid x:Name="RootGrid">
<VisualStateManager.VisualStateGroups>
<VisualStateGroup x:Name="CommonStates">
<VisualState x:Name="Normal">
<Storyboard>
<PointerUpThemeAnimation Storyboard.TargetName="RootGrid"/>
</Storyboard>
</VisualState>
<VisualState x:Name="PointerOver">
<Storyboard>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Fill" Storyboard.TargetName="BorderCircle">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlHighlightBaseMediumLowBrush}"/>
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground" Storyboard.TargetName="ContentPresenter">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlHighlightBaseHighBrush}"/>
</ObjectAnimationUsingKeyFrames>
<PointerUpThemeAnimation Storyboard.TargetName="RootGrid"/>
</Storyboard>
</VisualState>
<VisualState x:Name="Pressed">
<Storyboard>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Fill" Storyboard.TargetName="BorderCircle">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlBackgroundBaseMediumLowBrush}"/>
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground" Storyboard.TargetName="ContentPresenter">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlHighlightBaseHighBrush}"/>
</ObjectAnimationUsingKeyFrames>
<PointerDownThemeAnimation Storyboard.TargetName="RootGrid"/>
</Storyboard>
</VisualState>
<VisualState x:Name="Disabled">
<Storyboard>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Fill" Storyboard.TargetName="BorderCircle">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlBackgroundBaseLowBrush}"/>
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground" Storyboard.TargetName="ContentPresenter">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlDisabledBaseMediumLowBrush}"/>
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Stroke" Storyboard.TargetName="BorderCircle">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlDisabledTransparentBrush}"/>
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
</VisualStateGroup>
</VisualStateManager.VisualStateGroups>
<ContentPresenter x:Name="ContentPresenter" VerticalAlignment="Center" AutomationProperties.AccessibilityView="Raw" ContentTemplate="{TemplateBinding ContentTemplate}" ContentTransitions="{TemplateBinding ContentTransitions}" Content="{TemplateBinding Content}" HorizontalContentAlignment="{TemplateBinding HorizontalContentAlignment}" Padding="{TemplateBinding Padding}" VerticalContentAlignment="{TemplateBinding VerticalContentAlignment}"/>
<Ellipse x:Name="BorderCircle" Stroke="{TemplateBinding BorderBrush}" StrokeThickness="2"/>
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</Page.Resources>
<Grid Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
<Button Content="text" Width="50" Height="50" BorderBrush="Blue" Style="{StaticResource CircleButtonStyle}"/>
</Grid>
I've also made some changes in VisualStates so that it doesn't look weird once clicked/disabled.

I don't know if the OP is still interested in rounded corner buttons, but for sake of completeness I think it may be helpful for other users to point out, as the user peterincumbria said, that for the lastest build of Windows 10 (1809) there is a new property in the class Control: CornerRadius. So now the following code is enough:
<Button Content="DEMO"
Background="Transparent"
BorderThickness="1.0"
BorderBrush="White"
CornerRadius="10"
HorizontalAlignment="Center"
VerticalAlignment="Center"/>
Put this inside a Grid and we have a rounded corner button in the middle of the Page.

With version 1809 and later (even if you're targeting an earlier version like me below) you can just do this for an example of a round button:
<Button
Content="Stuff"
Windows10version1809:CornerRadius="90,90,90,90"
Height="64"
Width="64">
</Button>
and voila!
Make sure to add this at the top of your XAML with the other xmlns stuff.
xmlns:Windows10version1809="http://schemas.microsoft.com/winfx/2006/xaml/presentation?IsApiContractPresent(Windows.Foundation.UniversalApiContract, 7)"

Another sample
<Style x:Key="ProfileButtonStyle" TargetType="Button">
<Setter Property="Background" Value="{StaticResource AppBarHeaderBackground}"/>
<Setter Property="BorderBrush" Value="Transparent"/>
<Setter Property="FontFamily" Value="Segoe UI"/>
<Setter Property="Foreground" Value="{StaticResource SystemControlBackgroundAccentBrush}"></Setter>
<Setter Property="FontSize" Value="9"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="Button">
<Grid>
<StackPanel Orientation="Vertical">
<Grid Margin="0,0,0,0" >
<Ellipse x:Name="ButtonShape" Height="40" Width="40" Fill="#FFFDFCFC" HorizontalAlignment="Center"
Stroke="{StaticResource SystemControlBackgroundAccentBrush}" StrokeThickness="2" VerticalAlignment="Center"/>
<!--This glyph is the Contact (head and shoulders silhouette) glyph. -->
<TextBlock x:Name="Icon" Text="" FontFamily="Segoe UI Symbol" FontSize="18" HorizontalAlignment="Center"
VerticalAlignment="Center"/>
</Grid>
<TextBlock x:Name="ButtonContent" Text="{TemplateBinding Content}" HorizontalAlignment="Center"
FontFamily="Segoe UI" FontSize="12"/>
</StackPanel>
<VisualStateManager.VisualStateGroups>
<VisualStateGroup x:Name="CommonStates">
<VisualState x:Name="Normal"/>
<VisualState x:Name="PointerOver">
<Storyboard>
<ColorAnimation Duration="0" To="{Binding Source={StaticResource SymbolThemeFontFamily}, Path=Color}"
Storyboard.TargetProperty="(Rectangle.Fill).(SolidColorBrush.Color)"
Storyboard.TargetName="ButtonShape" />
</Storyboard>
</VisualState>
<VisualState x:Name="ButtonPressed">
<Storyboard>
<ColorAnimation Duration="0" To="#eeeeee"
Storyboard.TargetProperty="(Rectangle.Fill).(SolidColorBrush.Color)"
Storyboard.TargetName="ButtonEllipse" />
</Storyboard>
</VisualState>
</VisualStateGroup>
</VisualStateManager.VisualStateGroups>
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
Result
Or Create fully customizable cornerradius
//Create a template control xaml design
<ResourceDictionary
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:UWP.Library2.Controls">
<Style TargetType="local:CustomRoundedButton">
<Setter Property="CornerRadius" Value="10,10,10,10"></Setter>
<Setter Property="Background" Value="{ThemeResource SystemControlBackgroundBaseLowBrush}"/>
<Setter Property="Foreground" Value="{ThemeResource SystemControlForegroundBaseHighBrush}"/>
<Setter Property="BorderBrush" Value="{ThemeResource SystemControlForegroundTransparentBrush}"/>
<Setter Property="BorderThickness" Value="{ThemeResource ButtonBorderThemeThickness}"/>
<Setter Property="Padding" Value="8,4,8,4"/>
<Setter Property="HorizontalAlignment" Value="Left"/>
<Setter Property="VerticalAlignment" Value="Center"/>
<Setter Property="FontFamily" Value="{ThemeResource ContentControlThemeFontFamily}"/>
<Setter Property="FontWeight" Value="Normal"/>
<Setter Property="FontSize" Value="{ThemeResource ControlContentThemeFontSize}"/>
<Setter Property="UseSystemFocusVisuals" Value="True"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="local:CustomRoundedButton">
<Grid x:Name="RootGrid" Background="{TemplateBinding Background}" Height="{TemplateBinding Height}" Width="{TemplateBinding Width}" CornerRadius="{TemplateBinding CornerRadius}">
<VisualStateManager.VisualStateGroups>
<VisualStateGroup x:Name="CommonStates">
<VisualState x:Name="Normal">
<Storyboard>
<PointerUpThemeAnimation Storyboard.TargetName="RootGrid"/>
</Storyboard>
</VisualState>
<VisualState x:Name="PointerOver">
<Storyboard>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="ContentPresenter">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlHighlightBaseMediumLowBrush}"/>
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground" Storyboard.TargetName="ContentPresenter">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlHighlightBaseHighBrush}"/>
</ObjectAnimationUsingKeyFrames>
<PointerUpThemeAnimation Storyboard.TargetName="RootGrid"/>
</Storyboard>
</VisualState>
<VisualState x:Name="Pressed">
<Storyboard>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="RootGrid">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlBackgroundBaseMediumLowBrush}"/>
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="ContentPresenter">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlHighlightTransparentBrush}"/>
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground" Storyboard.TargetName="ContentPresenter">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlHighlightBaseHighBrush}"/>
</ObjectAnimationUsingKeyFrames>
<PointerDownThemeAnimation Storyboard.TargetName="RootGrid"/>
</Storyboard>
</VisualState>
<VisualState x:Name="Disabled">
<Storyboard>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="RootGrid">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlBackgroundBaseLowBrush}"/>
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground" Storyboard.TargetName="ContentPresenter">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlDisabledBaseLowBrush}"/>
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="ContentPresenter">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource SystemControlDisabledTransparentBrush}"/>
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
</VisualStateGroup>
</VisualStateManager.VisualStateGroups>
<!--<Rectangle RadiusX="60" RadiusY="60" Fill="{TemplateBinding Background}" Margin="0,0,10,0" />-->
<Grid Background="{TemplateBinding Background}" CornerRadius="{TemplateBinding CornerRadius}" Height="{TemplateBinding Height}" Width="{TemplateBinding Width}" ></Grid>
<ContentPresenter CornerRadius="{TemplateBinding CornerRadius}" x:Name="ContentPresenter"
AutomationProperties.AccessibilityView="Raw" BorderBrush="{TemplateBinding BorderBrush}"
BorderThickness="{TemplateBinding BorderThickness}"
ContentTemplate="{TemplateBinding ContentTemplate}"
ContentTransitions="{TemplateBinding ContentTransitions}"
Content="{TemplateBinding Content}"
HorizontalContentAlignment="{TemplateBinding HorizontalContentAlignment}"
Padding="{TemplateBinding Padding}"
VerticalContentAlignment="{TemplateBinding VerticalContentAlignment}"/>
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
//Template control.cs
public sealed class CustomRoundedButton : Button
{
private Grid _rootGrid = null;
public CustomRoundedButton()
{
this.DefaultStyleKey = typeof(CustomRoundedButton);
}
protected override void OnApplyTemplate()
{
base.OnApplyTemplate();
_rootGrid = GetTemplateChild("RootGrid") as Grid;
}
public CornerRadius CornerRadius
{
get { return (CornerRadius)GetValue(CornerRadiusProperty); }
set { SetValue(CornerRadiusProperty, value); }
}
public static readonly DependencyProperty CornerRadiusProperty =
DependencyProperty.Register("CornerRadius", typeof(CornerRadius), typeof(CustomRoundedButton), new PropertyMetadata(new CornerRadius(10,10,10,10)));
}
//Register to or merge dictionary from /Themes/Generic.xaml
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary Source="ms-appx:///UWP.Library2/Controls/CustomRoundedButton/CustomRoundedButton.xaml" />
</ResourceDictionary.MergedDictionaries>

The approach I just used was to simply add CornerRadius to the "RootGrid" grid in the Button template.
<Style TargetType="Button" x:Key="RoundedButton">
...
<Grid x:Name="RootGrid" CornerRadius="10" Background="{TemplateBinding Background}">
...
</Style>

How to change button image on clicking and again on releasing in windows phone

I want to change image1(let say) on clicking a button, to image2 and again on releasing I want to change it back to image1.
If any body knows please answer me. I am new to windows phone development.

<Button x:Name="MyButton" IsPressed="{Binding MyButtonIsPressed}"></Button>
C#
private bool _myButtonIsPressed;
public bool MyButtonIsPressed {
get{ return _myButtonIsPressed;}
set{
_myButtonIsPressed = value;
if(value==false){
MyButton.Content = ImageWhenReleasing;
}
else{
MyButton.Content = ImageWhenClicking;
}
}
}
I hope this can help you.

Change the Visibility of the images in the visual states of the button.
The style for the button:
<Style x:Key="ButtonStyle2"
TargetType="Button">
<Setter Property="Background"
Value="Transparent" />
<Setter Property="BorderBrush"
Value="{ThemeResource PhoneForegroundBrush}" />
<Setter Property="Foreground"
Value="{ThemeResource PhoneForegroundBrush}" />
<Setter Property="BorderThickness"
Value="{ThemeResource PhoneBorderThickness}" />
<Setter Property="FontFamily"
Value="{ThemeResource PhoneFontFamilyNormal}" />
<Setter Property="FontWeight"
Value="{ThemeResource PhoneButtonFontWeight}" />
<Setter Property="FontSize"
Value="{ThemeResource TextStyleLargeFontSize}" />
<Setter Property="Padding"
Value="{ThemeResource PhoneButtonContentPadding}" />
<Setter Property="MinHeight"
Value="{ThemeResource PhoneButtonMinHeight}" />
<Setter Property="MinWidth"
Value="{ThemeResource PhoneButtonMinWidth}" />
<Setter Property="HorizontalAlignment"
Value="Left" />
<Setter Property="VerticalAlignment"
Value="Center" />
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="Button">
<Grid x:Name="Grid"
Background="Transparent">
<VisualStateManager.VisualStateGroups>
<VisualStateGroup x:Name="CommonStates">
<VisualStateGroup.Transitions>
<VisualTransition From="Pressed"
To="PointerOver">
<Storyboard>
<PointerUpThemeAnimation Storyboard.TargetName="Grid" />
</Storyboard>
</VisualTransition>
<VisualTransition From="PointerOver"
To="Normal">
<Storyboard>
<PointerUpThemeAnimation Storyboard.TargetName="Grid" />
</Storyboard>
</VisualTransition>
<VisualTransition From="Pressed"
To="Normal">
<Storyboard>
<PointerUpThemeAnimation Storyboard.TargetName="Grid" />
</Storyboard>
</VisualTransition>
</VisualStateGroup.Transitions>
<VisualState x:Name="Normal" />
<VisualState x:Name="PointerOver" />
<VisualState x:Name="Pressed">
<Storyboard>
<PointerDownThemeAnimation Storyboard.TargetName="Grid" />
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground"
Storyboard.TargetName="ContentPresenter">
<DiscreteObjectKeyFrame KeyTime="0"
Value="{ThemeResource ButtonPressedForegroundThemeBrush}" />
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="(UIElement.Visibility)"
Storyboard.TargetName="image1">
<DiscreteObjectKeyFrame KeyTime="0">
<DiscreteObjectKeyFrame.Value>
<Visibility>Collapsed</Visibility>
</DiscreteObjectKeyFrame.Value>
</DiscreteObjectKeyFrame>
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="(UIElement.Visibility)"
Storyboard.TargetName="image2">
<DiscreteObjectKeyFrame KeyTime="0">
<DiscreteObjectKeyFrame.Value>
<Visibility>Visible</Visibility>
</DiscreteObjectKeyFrame.Value>
</DiscreteObjectKeyFrame>
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
<VisualState x:Name="Disabled">
<Storyboard>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground"
Storyboard.TargetName="ContentPresenter">
<DiscreteObjectKeyFrame KeyTime="0"
Value="{ThemeResource ButtonDisabledForegroundThemeBrush}" />
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush"
Storyboard.TargetName="Border">
<DiscreteObjectKeyFrame KeyTime="0"
Value="{ThemeResource ButtonDisabledBorderThemeBrush}" />
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background"
Storyboard.TargetName="Border">
<DiscreteObjectKeyFrame KeyTime="0"
Value="{ThemeResource ButtonDisabledBackgroundThemeBrush}" />
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
</VisualStateGroup>
</VisualStateManager.VisualStateGroups>
<Border x:Name="Border"
BorderBrush="{TemplateBinding BorderBrush}"
BorderThickness="{TemplateBinding BorderThickness}"
Background="{TemplateBinding Background}"
Margin="{ThemeResource PhoneTouchTargetOverhang}">
<Grid>
<BitmapIcon x:Name="image2"
UriSource="/Assets/Square71x71Logo.scale-240.png"
Foreground="Red"
Height="130" Visibility="Collapsed" />
<BitmapIcon x:Name="image1"
UriSource="/Assets/Square71x71Logo.scale-240.png"
Foreground="Yellow"
Height="150" />
<ContentPresenter x:Name="ContentPresenter"
AutomationProperties.AccessibilityView="Raw"
ContentTemplate="{TemplateBinding ContentTemplate}"
Content="{TemplateBinding Content}"
Foreground="{TemplateBinding Foreground}"
HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
Margin="{TemplateBinding Padding}"
VerticalAlignment="{TemplateBinding VerticalContentAlignment}" />
</Grid>
</Border>
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>

ComboBox-> adding this little triangle on the right

When using standard ComboBox in xaml in WindowsPhone application you get ComboBox which does not look like an old style ComboBox i.e. it does not have this little triangle on the right.
Can anyone point me to example, or give me a hint or solution:
How do we add this little triangle to ComboBox control.
All I need is to make ComboBox look like:
Thank you!
This is the code I am using:
<Page
x:Class="ComboBoxCustom.MainPage"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:ComboBoxCustom"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
mc:Ignorable="d"
Background="{ThemeResource ApplicationPageBackgroundThemeBrush}">
<Page.Resources>
<Style TargetType="ComboBox">
<Setter Property="Padding" Value="8,0" />
<Setter Property="MinWidth" Value="{ThemeResource ComboBoxThemeMinWidth}" />
<Setter Property="Foreground" Value="{ThemeResource ComboBoxForegroundThemeBrush}" />
<Setter Property="Background" Value="{ThemeResource ComboBoxBackgroundThemeBrush}" />
<Setter Property="BorderBrush" Value="{ThemeResource ComboBoxBorderThemeBrush}" />
<Setter Property="BorderThickness" Value="{ThemeResource ComboBoxBorderThemeThickness}" />
<Setter Property="TabNavigation" Value="Once" />
<Setter Property="ScrollViewer.HorizontalScrollBarVisibility" Value="Disabled" />
<Setter Property="ScrollViewer.VerticalScrollBarVisibility" Value="Auto" />
<Setter Property="ScrollViewer.HorizontalScrollMode" Value="Disabled" />
<Setter Property="ScrollViewer.VerticalScrollMode" Value="Auto" />
<Setter Property="ScrollViewer.IsVerticalRailEnabled" Value="True" />
<Setter Property="ScrollViewer.IsDeferredScrollingEnabled" Value="False" />
<Setter Property="ScrollViewer.BringIntoViewOnFocusChange" Value="True" />
<Setter Property="HorizontalContentAlignment" Value="Stretch" />
<Setter Property="FontFamily" Value="{ThemeResource ContentControlThemeFontFamily}" />
<Setter Property="FontSize" Value="{ThemeResource ControlContentThemeFontSize}" />
<Setter Property="ItemsPanel">
<Setter.Value>
<ItemsPanelTemplate>
<CarouselPanel />
</ItemsPanelTemplate>
</Setter.Value>
</Setter>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="ComboBox">
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="Auto" />
<RowDefinition Height="*" />
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*" />
<ColumnDefinition Width="32" />
</Grid.ColumnDefinitions>
<VisualStateManager.VisualStateGroups>
<VisualStateGroup x:Name="CommonStates">
<VisualState x:Name="Normal" />
<VisualState x:Name="PointerOver">
<Storyboard>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="Background"
Storyboard.TargetProperty="Background">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ComboBoxPointerOverBackgroundThemeBrush}" />
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="Background"
Storyboard.TargetProperty="BorderBrush">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ComboBoxPointerOverBorderThemeBrush}" />
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="Highlight"
Storyboard.TargetProperty="Fill">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ComboBoxSelectedPointerOverBackgroundThemeBrush}" />
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
<VisualState x:Name="Pressed">
<Storyboard>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="Background"
Storyboard.TargetProperty="Background">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ComboBoxPressedBackgroundThemeBrush}" />
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="Background"
Storyboard.TargetProperty="BorderBrush">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ComboBoxPressedBorderThemeBrush}" />
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="ContentPresenter"
Storyboard.TargetProperty="Foreground">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ComboBoxPressedForegroundThemeBrush}" />
</ObjectAnimationUsingKeyFrames>
<DoubleAnimation Storyboard.TargetName="PressedBackground"
Storyboard.TargetProperty="Opacity"
To="1"
Duration="0" />
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="DropDownGlyph"
Storyboard.TargetProperty="Foreground">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ComboBoxArrowPressedForegroundThemeBrush}" />
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
<VisualState x:Name="Disabled">
<Storyboard>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="Background"
Storyboard.TargetProperty="Background">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ComboBoxDisabledBackgroundThemeBrush}" />
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="Background"
Storyboard.TargetProperty="BorderBrush">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ComboBoxDisabledBorderThemeBrush}" />
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="ContentPresenter"
Storyboard.TargetProperty="Foreground">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ComboBoxDisabledForegroundThemeBrush}" />
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="DropDownGlyph"
Storyboard.TargetProperty="Foreground">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ComboBoxArrowDisabledForegroundThemeBrush}" />
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
</VisualStateGroup>
<VisualStateGroup x:Name="FocusStates">
<VisualState x:Name="Focused">
<Storyboard>
<DoubleAnimation Storyboard.TargetName="HighlightBackground"
Storyboard.TargetProperty="Opacity"
To="1"
Duration="0" />
<DoubleAnimation Storyboard.TargetName="Highlight"
Storyboard.TargetProperty="Opacity"
To="1"
Duration="0" />
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="ContentPresenter"
Storyboard.TargetProperty="Foreground">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ComboBoxFocusedForegroundThemeBrush}" />
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
<VisualState x:Name="FocusedPressed">
<Storyboard>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="ContentPresenter"
Storyboard.TargetProperty="Foreground">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ComboBoxPressedForegroundThemeBrush}" />
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="Highlight"
Storyboard.TargetProperty="Fill">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource ComboBoxPressedHighlightThemeBrush}" />
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
<VisualState x:Name="Unfocused" />
<VisualState x:Name="PointerFocused" />
<VisualState x:Name="FocusedDropDown">
<Storyboard>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="PopupBorder"
Storyboard.TargetProperty="Visibility"
Duration="0">
<DiscreteObjectKeyFrame KeyTime="0">
<DiscreteObjectKeyFrame.Value>
<Visibility>Visible</Visibility>
</DiscreteObjectKeyFrame.Value>
</DiscreteObjectKeyFrame>
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
</VisualStateGroup>
<VisualStateGroup x:Name="DropDownStates">
<VisualState x:Name="Opened">
<Storyboard>
<SplitOpenThemeAnimation
OpenedTargetName="PopupBorder"
ContentTargetName="ScrollViewer"
ClosedTargetName="ContentPresenter"
ContentTranslationOffset="0"
OffsetFromCenter="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=TemplateSettings.DropDownOffset}"
OpenedLength="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=TemplateSettings.DropDownOpenedHeight}"
ClosedLength="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=TemplateSettings.DropDownClosedHeight}" />
</Storyboard>
</VisualState>
<VisualState x:Name="Closed">
<Storyboard>
<SplitCloseThemeAnimation
OpenedTargetName="PopupBorder"
ContentTargetName="ScrollViewer"
ClosedTargetName="ContentPresenter"
ContentTranslationOffset="40"
OffsetFromCenter="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=TemplateSettings.DropDownOffset}"
ContentTranslationDirection="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=TemplateSettings.SelectedItemDirection}"
OpenedLength="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=TemplateSettings.DropDownOpenedHeight}"
ClosedLength="{Binding RelativeSource={RelativeSource TemplatedParent}, Path=TemplateSettings.DropDownClosedHeight}" />
</Storyboard>
</VisualState>
</VisualStateGroup>
</VisualStateManager.VisualStateGroups>
<ContentPresenter x:Name="HeaderContentPresenter"
Foreground="{ThemeResource ComboBoxHeaderForegroundThemeBrush}"
Margin="{ThemeResource ComboBoxHeaderThemeMargin}"
FlowDirection="{TemplateBinding FlowDirection}"
FontWeight="{ThemeResource ComboBoxHeaderThemeFontWeight}"
Visibility="Collapsed"
Content="{TemplateBinding Header}"
ContentTemplate="{TemplateBinding HeaderTemplate}" />
<Border x:Name="Background"
Grid.Row="1"
Grid.ColumnSpan="2"
Background="{TemplateBinding Background}"
BorderBrush="{TemplateBinding BorderBrush}"
BorderThickness="{TemplateBinding BorderThickness}" />
<Rectangle x:Name="PressedBackground"
Grid.Row="1"
Fill="{ThemeResource ComboBoxPressedHighlightThemeBrush}"
Margin="{TemplateBinding BorderThickness}"
Opacity="0" />
<Border x:Name="HighlightBackground"
Grid.Row="1"
Grid.ColumnSpan="2"
Background="{ThemeResource ComboBoxFocusedBackgroundThemeBrush}"
BorderBrush="{ThemeResource ComboBoxFocusedBorderThemeBrush}"
BorderThickness="{TemplateBinding BorderThickness}"
Opacity="0" />
<Rectangle x:Name="Highlight"
Grid.Row="1"
Fill="{ThemeResource ComboBoxSelectedBackgroundThemeBrush}"
Margin="{TemplateBinding BorderThickness}"
Opacity="0" />
<ContentPresenter x:Name="ContentPresenter"
Grid.Row="1"
Margin="{TemplateBinding Padding}"
HorizontalAlignment="{TemplateBinding HorizontalContentAlignment}"
VerticalAlignment="{TemplateBinding VerticalContentAlignment}">
<TextBlock x:Name="PlaceholderTextBlock"
Text="{TemplateBinding PlaceholderText}"
Foreground="{ThemeResource ComboBoxPlaceholderTextForegroundThemeBrush}"
FontWeight="{ThemeResource ComboBoxPlaceholderTextThemeFontWeight}"/>
</ContentPresenter>
<TextBlock x:Name="DropDownGlyph"
Text=""
Grid.Row="1"
Grid.Column="1"
IsHitTestVisible="False"
Margin="0,0,6,4"
Foreground="{ThemeResource ComboBoxArrowForegroundThemeBrush}"
FontWeight="Bold"
FontSize="{ThemeResource ComboBoxArrowThemeFontSize}"
FontFamily="{ThemeResource SymbolThemeFontFamily}"
HorizontalAlignment="Right"
VerticalAlignment="Center"
AutomationProperties.AccessibilityView="Raw"/>
<Popup x:Name="Popup">
<Border x:Name="PopupBorder"
Background="{ThemeResource ComboBoxPopupBackgroundThemeBrush}"
BorderBrush="{ThemeResource ComboBoxPopupBorderThemeBrush}"
BorderThickness="{ThemeResource ComboBoxPopupBorderThemeThickness}"
HorizontalAlignment="Stretch">
<ScrollViewer x:Name="ScrollViewer" Foreground="{ThemeResource ComboBoxPopupForegroundThemeBrush}"
MinWidth="{ThemeResource ComboBoxPopupThemeMinWidth}"
VerticalSnapPointsType="OptionalSingle"
VerticalSnapPointsAlignment="Near"
HorizontalScrollMode="{TemplateBinding ScrollViewer.HorizontalScrollMode}"
HorizontalScrollBarVisibility="{TemplateBinding ScrollViewer.HorizontalScrollBarVisibility}"
VerticalScrollMode="{TemplateBinding ScrollViewer.VerticalScrollMode}"
VerticalScrollBarVisibility="{TemplateBinding ScrollViewer.VerticalScrollBarVisibility}"
IsHorizontalRailEnabled="{TemplateBinding ScrollViewer.IsHorizontalRailEnabled}"
IsVerticalRailEnabled="{TemplateBinding ScrollViewer.IsVerticalRailEnabled}"
IsDeferredScrollingEnabled="{TemplateBinding ScrollViewer.IsDeferredScrollingEnabled}"
BringIntoViewOnFocusChange="{TemplateBinding ScrollViewer.BringIntoViewOnFocusChange}"
ZoomMode="Disabled"
AutomationProperties.AccessibilityView="Raw">
<ItemsPresenter/>
</ScrollViewer>
</Border>
</Popup>
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</Page.Resources>
<Grid>
<ComboBox Header="asdswd"
Height="100">
<ComboBox.Items>
<TextBox Text="AAA"/>
<TextBox Text="BBB"/>
</ComboBox.Items>
</ComboBox>
</Grid>
</Page>

This is the default styling for a Windows Phone ComboBox:
https://msdn.microsoft.com/en-us/library/windows/apps/xaml/jj709912.aspx
The x:name="DropDownGlyph" is what you are looking for. It looks like the symbol you want to display is &#57361. If it isn't showing up it could be a styling somewhere else you are using that is overriding the default.

Transparent textbox when textbox GotFocussed Windows Phone 8.1?

I need to have transparent textbox, in my WindowsPhone 8.1 Runtime application.
I made Background="Transparent" to the textbox, so it is transparent when it is loaded.
But on focus, background color changed to white. I write the following code, to make it transparent. But it doesn't run.!
<TextBox Background="Transparent" GotFocus="titleBox_GotFocus" />
C#
private void titleBox_GotFocus(object sender, RoutedEventArgs e)
{
titleBox.Background = new SolidColorBrush(Colors.Transparent);
}

The problem is that when you the TextBox gets focused, the StoryBoard is changing the Background to ThemeResource - the TExtBox by default is designed to do that. Of course you can change it - as you are targetting WP8.1 Runtime, you will have to play with VisualStaes of your TextBox. To say more, you will have to change Focused state:
<VisualState x:Name="Focused">
<Storyboard>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="BorderElement">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextSelectionHighlightColorThemeBrush}"/>
</ObjectAnimationUsingKeyFrames>
<DoubleAnimation Duration="0" To="0" Storyboard.TargetProperty="Opacity" Storyboard.TargetName="PlaceholderTextContentPresenter"/>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="BackgroundElement">
<DiscreteObjectKeyFrame KeyTime="0" Value="Transparent"/>
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
In the code above, I've changed the third animation, so now it sets Transparent to Background.
The complete Style (taken from Blend) can look like this:
<Page.Resources>
<Style x:Key="TransparentStyle" TargetType="TextBox">
<Setter Property="MinWidth" Value="{ThemeResource TextControlThemeMinWidth}"/>
<Setter Property="MinHeight" Value="{ThemeResource TextControlThemeMinHeight}"/>
<Setter Property="Foreground" Value="{ThemeResource TextBoxForegroundThemeBrush}"/>
<Setter Property="SelectionHighlightColor" Value="{ThemeResource TextSelectionHighlightColorThemeBrush}"/>
<Setter Property="Background" Value="{ThemeResource TextBoxBackgroundThemeBrush}"/>
<Setter Property="BorderBrush" Value="{ThemeResource TextBoxBorderThemeBrush}"/>
<Setter Property="BorderThickness" Value="{ThemeResource TextControlBorderThemeThickness}"/>
<Setter Property="FontFamily" Value="{ThemeResource PhoneFontFamilyNormal}"/>
<Setter Property="FontSize" Value="{ThemeResource ContentControlFontSize}"/>
<Setter Property="TextWrapping" Value="NoWrap"/>
<Setter Property="ScrollViewer.HorizontalScrollMode" Value="Auto"/>
<Setter Property="ScrollViewer.VerticalScrollMode" Value="Auto"/>
<Setter Property="ScrollViewer.HorizontalScrollBarVisibility" Value="Hidden"/>
<Setter Property="ScrollViewer.VerticalScrollBarVisibility" Value="Hidden"/>
<Setter Property="ScrollViewer.IsDeferredScrollingEnabled" Value="False"/>
<Setter Property="Padding" Value="{ThemeResource TextControlThemePadding}"/>
<Setter Property="Margin" Value="{ThemeResource TextControlMarginThemeThickness}"/>
<Setter Property="VerticalAlignment" Value="Top"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="TextBox">
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="Auto"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<VisualStateManager.VisualStateGroups>
<VisualStateGroup x:Name="CommonStates">
<VisualState x:Name="Disabled">
<Storyboard>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="BackgroundElement">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextBoxDisabledBackgroundThemeBrush}"/>
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="BorderElement">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextBoxDisabledBorderThemeBrush}"/>
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground" Storyboard.TargetName="ContentElement">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextBoxDisabledForegroundThemeBrush}"/>
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground" Storyboard.TargetName="PlaceholderTextContentPresenter">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextBoxDisabledForegroundThemeBrush}"/>
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
<VisualState x:Name="Normal">
<Storyboard>
<DoubleAnimation Duration="0" To="{ThemeResource TextControlBackgroundThemeOpacity}" Storyboard.TargetProperty="Opacity" Storyboard.TargetName="BackgroundElement"/>
<DoubleAnimation Duration="0" To="{ThemeResource TextControlBorderThemeOpacity}" Storyboard.TargetProperty="Opacity" Storyboard.TargetName="BorderElement"/>
</Storyboard>
</VisualState>
<VisualState x:Name="Focused">
<Storyboard>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="BorderBrush" Storyboard.TargetName="BorderElement">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextSelectionHighlightColorThemeBrush}"/>
</ObjectAnimationUsingKeyFrames>
<DoubleAnimation Duration="0" To="0" Storyboard.TargetProperty="Opacity" Storyboard.TargetName="PlaceholderTextContentPresenter"/>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Background" Storyboard.TargetName="BackgroundElement">
<DiscreteObjectKeyFrame KeyTime="0" Value="Transparent"/>
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
</VisualStateGroup>
</VisualStateManager.VisualStateGroups>
<Border x:Name="BackgroundElement" Background="{TemplateBinding Background}" Margin="{TemplateBinding BorderThickness}" Grid.Row="1"/>
<Border x:Name="BorderElement" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" Grid.Row="1"/>
<ContentPresenter x:Name="HeaderContentPresenter" ContentTemplate="{TemplateBinding HeaderTemplate}" Content="{TemplateBinding Header}" Margin="{ThemeResource TextControlHeaderMarginThemeThickness}" Grid.Row="0" Style="{StaticResource HeaderContentPresenterStyle}"/>
<ScrollViewer x:Name="ContentElement" AutomationProperties.AccessibilityView="Raw" HorizontalScrollMode="{TemplateBinding ScrollViewer.HorizontalScrollMode}" HorizontalScrollBarVisibility="{TemplateBinding ScrollViewer.HorizontalScrollBarVisibility}" IsTabStop="False" IsHorizontalRailEnabled="{TemplateBinding ScrollViewer.IsHorizontalRailEnabled}" IsVerticalRailEnabled="{TemplateBinding ScrollViewer.IsVerticalRailEnabled}" IsDeferredScrollingEnabled="{TemplateBinding ScrollViewer.IsDeferredScrollingEnabled}" Margin="{TemplateBinding BorderThickness}" MinHeight="{ThemeResource TextControlThemeMinHeight}" Padding="{TemplateBinding Padding}" Grid.Row="1" VerticalScrollBarVisibility="{TemplateBinding ScrollViewer.VerticalScrollBarVisibility}" VerticalScrollMode="{TemplateBinding ScrollViewer.VerticalScrollMode}" ZoomMode="Disabled"/>
<ContentControl x:Name="PlaceholderTextContentPresenter" Content="{TemplateBinding PlaceholderText}" Foreground="{ThemeResource TextBoxPlaceholderTextThemeBrush}" FontSize="{ThemeResource ContentControlFontSize}" IsTabStop="False" Margin="{TemplateBinding BorderThickness}" Padding="{TemplateBinding Padding}" Grid.Row="1"/>
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</Page.Resources>
And you use it like this:
<TextBox Background="Transparent" GotFocus="titleBox_GotFocus" Style="{StaticResource TransparentStyle}"/>

You can make the Textbox transparent always by applying the following style,
Style:
<ControlTemplate x:Key="PhoneDisabledTextBoxTemplate" TargetType="TextBox">
<ContentControl x:Name="ContentElement" BorderThickness="0" HorizontalContentAlignment="Stretch" Margin="{StaticResource PhoneTextBoxInnerMargin}" Padding="{TemplateBinding Padding}" VerticalContentAlignment="Stretch"/>
</ControlTemplate>
<Style x:Key="TransparentTextBoxStyle" TargetType="TextBox">
<Setter Property="FontFamily" Value="{StaticResource PhoneFontFamilyNormal}"/>
<Setter Property="FontSize" Value="{StaticResource PhoneFontSizeMediumLarge}"/>
<Setter Property="Background" Value="{StaticResource PhoneTextBoxBrush}"/>
<Setter Property="Foreground" Value="{StaticResource PhoneTextBoxForegroundBrush}"/>
<Setter Property="BorderBrush" Value="{StaticResource PhoneTextBoxBrush}"/>
<Setter Property="SelectionBackground" Value="{StaticResource PhoneAccentBrush}"/>
<Setter Property="SelectionForeground" Value="{StaticResource PhoneTextBoxSelectionForegroundBrush}"/>
<Setter Property="BorderThickness" Value="{StaticResource PhoneBorderThickness}"/>
<Setter Property="Padding" Value="2"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="TextBox">
<Grid Background="Transparent">
<VisualStateManager.VisualStateGroups>
<VisualStateGroup x:Name="CommonStates">
<VisualState x:Name="Normal"/>
<VisualState x:Name="MouseOver"/>
<VisualState x:Name="Disabled">
<Storyboard>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Visibility" Storyboard.TargetName="EnabledBorder">
<DiscreteObjectKeyFrame KeyTime="0">
<DiscreteObjectKeyFrame.Value>
<Visibility>Collapsed</Visibility>
</DiscreteObjectKeyFrame.Value>
</DiscreteObjectKeyFrame>
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Visibility" Storyboard.TargetName="DisabledOrReadonlyBorder">
<DiscreteObjectKeyFrame KeyTime="0">
<DiscreteObjectKeyFrame.Value>
<Visibility>Visible</Visibility>
</DiscreteObjectKeyFrame.Value>
</DiscreteObjectKeyFrame>
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
<VisualState x:Name="ReadOnly">
<Storyboard>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Visibility" Storyboard.TargetName="EnabledBorder">
<DiscreteObjectKeyFrame KeyTime="0">
<DiscreteObjectKeyFrame.Value>
<Visibility>Collapsed</Visibility>
</DiscreteObjectKeyFrame.Value>
</DiscreteObjectKeyFrame>
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Visibility" Storyboard.TargetName="DisabledOrReadonlyBorder">
<DiscreteObjectKeyFrame KeyTime="0">
<DiscreteObjectKeyFrame.Value>
<Visibility>Visible</Visibility>
</DiscreteObjectKeyFrame.Value>
</DiscreteObjectKeyFrame>
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetProperty="Foreground" Storyboard.TargetName="DisabledOrReadonlyContent">
<DiscreteObjectKeyFrame KeyTime="0" Value="{StaticResource PhoneTextBoxReadOnlyBrush}"/>
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
</VisualStateGroup>
<VisualStateGroup x:Name="FocusStates">
<VisualState x:Name="Focused"/>
<VisualState x:Name="Unfocused"/>
</VisualStateGroup>
<VisualStateGroup x:Name="ValidationStates">
<VisualState x:Name="InvalidFocused"/>
<VisualState x:Name="Valid"/>
<VisualState x:Name="InvalidUnfocused"/>
</VisualStateGroup>
</VisualStateManager.VisualStateGroups>
<Border x:Name="EnabledBorder" BorderThickness="{TemplateBinding BorderThickness}" Margin="{StaticResource PhoneTouchTargetOverhang}">
<ContentControl x:Name="ContentElement" BorderThickness="0" HorizontalContentAlignment="Stretch" Margin="{StaticResource PhoneTextBoxInnerMargin}" Padding="{TemplateBinding Padding}" VerticalContentAlignment="Stretch"/>
</Border>
<Border x:Name="DisabledOrReadonlyBorder" BorderThickness="{TemplateBinding BorderThickness}" Margin="{StaticResource PhoneTouchTargetOverhang}" Visibility="Collapsed">
<TextBox x:Name="DisabledOrReadonlyContent" Foreground="{StaticResource PhoneDisabledBrush}" FontWeight="{TemplateBinding FontWeight}" FontStyle="{TemplateBinding FontStyle}" FontSize="{TemplateBinding FontSize}" FontFamily="{TemplateBinding FontFamily}" IsReadOnly="True" SelectionForeground="{TemplateBinding SelectionForeground}" SelectionBackground="{TemplateBinding SelectionBackground}" TextAlignment="{TemplateBinding TextAlignment}" TextWrapping="{TemplateBinding TextWrapping}" Text="{TemplateBinding Text}" Template="{StaticResource PhoneDisabledTextBoxTemplate}"/>
</Border>
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
XAML:
<TextBox Style="{StaticResource TransparentTextBoxStyle}"/>
Refered from : TRANSPARENT TEXTBOX FOR WINDOWS PHONE

My TextBox vanishes when I add a VisualState

I try to use Visual States in a Windows Phone 8 application (C#-XAML). The screen is dark. Here is the style I defined in App.xaml:
<Style x:Key="StyleDeBaseTextBox" TargetType="TextBox">
<Setter Property="Background" Value="Transparent"/>
<Setter Property="Foreground" Value="White"/>
<Setter Property="SelectionBackground" Value="{StaticResource PhoneAccentBrush}"/>
<Setter Property="SelectionForeground" Value="{StaticResource PhoneBackgroundBrush}"/>
<Setter Property="InputScope" Value="Text"/>
<Setter Property="BorderBrush" Value="Transparent"/>
<Setter Property="Height" Value="40px"/>
</Style>
It works, but when the TextBox has the focus, its background becomes white. As the foreground color remains white, you can't read what you write. So, I added this property, but the result is that my TextBox disappears (though I get no error message):
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="TextBox">
<Grid>
<VisualStateManager.VisualStateGroups>
<VisualStateGroup x:Name="CommonStates">
<VisualState x:Name="Normal"/>
<VisualState x:Name="Disabled"/>
<VisualState x:Name="PointerOver"/>
<VisualState x:Name="ButtonVisible"/>
<VisualState x:Name="ButtonCollapsed"/>
<VisualState x:Name="Focused">
<Storyboard>
<DoubleAnimation Storyboard.TargetName="TextBox" Storyboard.TargetProperty="BorderBrush" To="Green" Duration="0"/>
</Storyboard>
</VisualState>
</VisualStateGroup>
</VisualStateManager.VisualStateGroups>
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>

TextBox vanishes because you override its ControlTemplate and doesn't provide any content host.
Copy the default template of TextBox from MSDN and change the StoryBoard as per your needs.
Anyhow this is ControlTemplate which you can use. It also change border brush to green on focus. Hope this is what you want:
<ControlTemplate TargetType="TextBoxBase">
<Border BorderThickness="{TemplateBinding Border.BorderThickness}"
BorderBrush="{TemplateBinding Border.BorderBrush}"
Background="{TemplateBinding Panel.Background}"
Name="border"
SnapsToDevicePixels="True">
<ScrollViewer HorizontalScrollBarVisibility="Hidden"
VerticalScrollBarVisibility="Hidden"
Name="PART_ContentHost"
Focusable="False" />
</Border>
<ControlTemplate.Triggers>
<Trigger Property="UIElement.IsEnabled" Value="False">
<Setter Property="UIElement.Opacity" TargetName="border" Value="0.56"/>
</Trigger>
<Trigger Property="UIElement.IsMouseOver" Value="True">
<Setter Property="Border.BorderBrush" TargetName="border"
Value="#FF7EB4EA"/>
</Trigger>
<Trigger Property="UIElement.IsKeyboardFocused" Value="True">
<Setter Property="Border.BorderBrush" TargetName="border"
Value="Green"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>

Windows Phone Control Template : MSDN Link
<Style TargetType="TextBox">
<Setter Property="MinWidth" Value="{ThemeResource TextControlThemeMinWidth}" />
<Setter Property="MinHeight" Value="{ThemeResource TextControlThemeMinHeight}" />
<Setter Property="Foreground" Value="{ThemeResource TextBoxForegroundThemeBrush}" />
<Setter Property="Background" Value="{ThemeResource TextBoxBackgroundThemeBrush}" />
<Setter Property="BorderBrush" Value="{ThemeResource TextBoxBorderThemeBrush}" />
<Setter Property="SelectionHighlightColor" Value="{ThemeResource TextSelectionHighlightColorThemeBrush}" />
<Setter Property="BorderThickness" Value="{ThemeResource TextControlBorderThemeThickness}" />
<Setter Property="FontFamily" Value="{ThemeResource ContentControlThemeFontFamily}" />
<Setter Property="FontSize" Value="{ThemeResource ControlContentThemeFontSize}" />
<Setter Property="ScrollViewer.HorizontalScrollBarVisibility" Value="Hidden" />
<Setter Property="ScrollViewer.VerticalScrollBarVisibility" Value="Hidden" />
<Setter Property="ScrollViewer.IsDeferredScrollingEnabled" Value="False" />
<Setter Property="Padding" Value="{ThemeResource TextControlThemePadding}"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="TextBox">
<Grid>
<Grid.Resources>
<Style x:Name="DeleteButtonStyle" TargetType="Button">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="Button">
<Grid>
<VisualStateManager.VisualStateGroups>
<VisualStateGroup x:Name="CommonStates">
<VisualState x:Name="Normal" />
<VisualState x:Name="PointerOver">
<Storyboard>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="BackgroundElement"
Storyboard.TargetProperty="Background">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextBoxButtonPointerOverBackgroundThemeBrush}" />
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="BorderElement"
Storyboard.TargetProperty="BorderBrush">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextBoxButtonPointerOverBorderThemeBrush}" />
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="GlyphElement"
Storyboard.TargetProperty="Foreground">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextBoxButtonPointerOverForegroundThemeBrush}" />
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
<VisualState x:Name="Pressed">
<Storyboard>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="BackgroundElement"
Storyboard.TargetProperty="Background">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextBoxButtonPressedBackgroundThemeBrush}" />
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="BorderElement"
Storyboard.TargetProperty="BorderBrush">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextBoxButtonPressedBorderThemeBrush}" />
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="GlyphElement"
Storyboard.TargetProperty="Foreground">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextBoxButtonPressedForegroundThemeBrush}" />
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
<VisualState x:Name="Disabled">
<Storyboard>
<DoubleAnimation Storyboard.TargetName="BackgroundElement"
Storyboard.TargetProperty="Opacity"
To="0"
Duration="0" />
<DoubleAnimation Storyboard.TargetName="BorderElement"
Storyboard.TargetProperty="Opacity"
To="0"
Duration="0" />
</Storyboard>
</VisualState>
</VisualStateGroup>
</VisualStateManager.VisualStateGroups>
<Border x:Name="BorderElement"
BorderBrush="{ThemeResource TextBoxButtonBorderThemeBrush}"
BorderThickness="{TemplateBinding BorderThickness}"/>
<Border x:Name="BackgroundElement"
Background="{ThemeResource TextBoxButtonBackgroundThemeBrush}"
Margin="{TemplateBinding BorderThickness}">
<TextBlock x:Name="GlyphElement"
Foreground="{ThemeResource TextBoxButtonForegroundThemeBrush}"
VerticalAlignment="Center"
HorizontalAlignment="Center"
FontStyle="Normal"
Text=""
FontFamily="{ThemeResource SymbolThemeFontFamily}"
AutomationProperties.AccessibilityView="Raw"/>
</Border>
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</Grid.Resources>
<VisualStateManager.VisualStateGroups>
<VisualStateGroup x:Name="CommonStates">
<VisualState x:Name="Disabled">
<Storyboard>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="BackgroundElement"
Storyboard.TargetProperty="Background">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextBoxDisabledBackgroundThemeBrush}" />
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="BorderElement"
Storyboard.TargetProperty="BorderBrush">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextBoxDisabledBorderThemeBrush}" />
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="ContentElement"
Storyboard.TargetProperty="Foreground">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextBoxDisabledForegroundThemeBrush}" />
</ObjectAnimationUsingKeyFrames>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="PlaceholderTextContentPresenter"
Storyboard.TargetProperty="Foreground">
<DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextBoxDisabledForegroundThemeBrush}" />
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
<VisualState x:Name="Normal">
<Storyboard>
<DoubleAnimation Storyboard.TargetName="BackgroundElement"
Storyboard.TargetProperty="Opacity"
Duration="0"
To="{ThemeResource TextControlBackgroundThemeOpacity}" />
<DoubleAnimation Storyboard.TargetName="BorderElement"
Storyboard.TargetProperty="Opacity"
Duration="0"
To="{ThemeResource TextControlBorderThemeOpacity}" />
</Storyboard>
</VisualState>
<VisualState x:Name="PointerOver">
<Storyboard>
<DoubleAnimation Storyboard.TargetName="BackgroundElement"
Storyboard.TargetProperty="Opacity"
Duration="0"
To="{ThemeResource TextControlPointerOverBackgroundThemeOpacity}" />
<DoubleAnimation Storyboard.TargetName="BorderElement"
Storyboard.TargetProperty="Opacity"
Duration="0"
To="{ThemeResource TextControlPointerOverBorderThemeOpacity}" />
</Storyboard>
</VisualState>
<VisualState x:Name="Focused" />
</VisualStateGroup>
<VisualStateGroup x:Name="ButtonStates">
<VisualState x:Name="ButtonVisible">
<Storyboard>
<ObjectAnimationUsingKeyFrames Storyboard.TargetName="DeleteButton"
Storyboard.TargetProperty="Visibility">
<DiscreteObjectKeyFrame KeyTime="0">
<DiscreteObjectKeyFrame.Value>
<Visibility>Visible</Visibility>
</DiscreteObjectKeyFrame.Value>
</DiscreteObjectKeyFrame>
</ObjectAnimationUsingKeyFrames>
</Storyboard>
</VisualState>
<VisualState x:Name="ButtonCollapsed" />
</VisualStateGroup>
</VisualStateManager.VisualStateGroups>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="*" />
<ColumnDefinition Width="Auto" />
</Grid.ColumnDefinitions>
<Grid.RowDefinitions>
<RowDefinition Height="Auto" />
<RowDefinition Height="*" />
</Grid.RowDefinitions>
<Border x:Name="BackgroundElement"
Grid.Row="1"
Background="{TemplateBinding Background}"
Margin="{TemplateBinding BorderThickness}"
Grid.ColumnSpan="2"
Grid.RowSpan="1"/>
<Border x:Name="BorderElement"
Grid.Row="1"
BorderBrush="{TemplateBinding BorderBrush}"
BorderThickness="{TemplateBinding BorderThickness}"
Grid.ColumnSpan="2"
Grid.RowSpan="1"/>
<ContentPresenter x:Name="HeaderContentPresenter"
Grid.Row="0"
Foreground="{ThemeResource TextBoxForegroundHeaderThemeBrush}"
Margin="0,4,0,4"
Grid.ColumnSpan="2"
Content="{TemplateBinding Header}"
ContentTemplate="{TemplateBinding HeaderTemplate}"
FontWeight="Semilight" />
<ScrollViewer x:Name="ContentElement"
Grid.Row="1"
HorizontalScrollMode="{TemplateBinding ScrollViewer.HorizontalScrollMode}"
HorizontalScrollBarVisibility="{TemplateBinding ScrollViewer.HorizontalScrollBarVisibility}"
VerticalScrollMode="{TemplateBinding ScrollViewer.VerticalScrollMode}"
VerticalScrollBarVisibility="{TemplateBinding ScrollViewer.VerticalScrollBarVisibility}"
IsHorizontalRailEnabled="{TemplateBinding ScrollViewer.IsHorizontalRailEnabled}"
IsVerticalRailEnabled="{TemplateBinding ScrollViewer.IsVerticalRailEnabled}"
IsDeferredScrollingEnabled="{TemplateBinding ScrollViewer.IsDeferredScrollingEnabled}"
Margin="{TemplateBinding BorderThickness}"
Padding="{TemplateBinding Padding}"
IsTabStop="False"
AutomationProperties.AccessibilityView="Raw"
ZoomMode="Disabled" />
<ContentControl x:Name="PlaceholderTextContentPresenter"
Grid.Row="1"
Foreground="{ThemeResource TextBoxPlaceholderTextThemeBrush}"
Margin="{TemplateBinding BorderThickness}"
Padding="{TemplateBinding Padding}"
IsTabStop="False"
Grid.ColumnSpan="2"
Content="{TemplateBinding PlaceholderText}"
IsHitTestVisible="False"/>
<Button x:Name="DeleteButton"
Grid.Row="1"
Style="{StaticResource DeleteButtonStyle}"
BorderThickness="{TemplateBinding BorderThickness}"
IsTabStop="False"
Grid.Column="1"
Visibility="Collapsed"
FontSize="{TemplateBinding FontSize}"
VerticalAlignment="Stretch"/>
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>