I have two buttons. I want change second Button BackgroundColor using Triggers When I click first button but I am unable to do it. The code I am trying
<Button Text="button 1" x:Name="btn1" HorizontalOptions="Fill">
<Button.Triggers>
<Trigger TargetType="Button" Binding="{Binding Source={x:Reference btn2} Property="IsEnabled">
<Setter Property="BackgroundColor" Value="Red"></Setter>
</Trigger>
</Button.Triggers>
</Button>
<Button Text="button 2" x:Name="btn2" HorizontalOptions="Fill" />
I even have no idea where to write click event for this.
The best way to do that is to use ViewModel rather than the Code base.
Approach 1 : using the ViewModel
public class YourViewModel : BaseViewModel
{
public ICommand Button1Command { get; set; }
private bool _enableButton2;
public bool EnableButton2
{
get
{
return _enableButton2;
}
set
{
_enableButton2= value;
RaisePropertyChanged();
}
}
public YourViewModel()
{
Button1Command =new Command(Button1Clicked);
}
private void Button1Clicked()
{
EnableButton2=true; //Whenever you need to enable or disable set it true/false
}
}
Now you have your ViewModel, You need to implement your UI like this :
<Button x:Name="button1" Text="Button 1" Command="{Binding Button1Command }" />
<Button x:Name="button2" Text="Button 2">
<Button.Triggers>
<DataTrigger TargetType="Button" Binding="{Binding EnableButton2}" Value="false">
<Setter Property="BackgroundColor" Value="#dbe1e5" />
<Setter Property="TextColor" Value="#bfcfd5" />
</DataTrigger>
<DataTrigger TargetType="Button" Binding="{Binding EnableButton2" Value="true">
<Setter Property="BackgroundColor" Value="Red" />
<Setter Property="TextColor" Value="#FFFFFF" />
</DataTrigger>
</Button.Triggers>
</Button>
This is the MVVM way to do this; let me know if you want Code Base style.
Related
I have a ComboBox with an ItemTemplateSelector, using 2 different DataTemplates, one for when its drop down is visible and another when it is not. For the drop down template, each ComboBox item is represented by a TextBlock and a Button that should only be visible whenever that item is focused/highlighted/mouse over. This is what I've tried:
<ComboBox x:Name="Windows" ItemsSource="{Binding Windows}" SelectedItem="{Binding Window}" Focusable="False" MaxDropDownHeight="238">
<ComboBox.ItemTemplateSelector>
<s:ComboBoxItemTemplateSelector>
<s:ComboBoxItemTemplateSelector.SelectedTemplate>
<DataTemplate>
<TextBlock Text="{Binding TitleShort}" ToolTip="{Binding Title}" />
</DataTemplate>
</s:ComboBoxItemTemplateSelector.SelectedTemplate>
<s:ComboBoxItemTemplateSelector.DropDownTemplate>
<DataTemplate>
<StackPanel Orientation="Horizontal" VerticalAlignment="Center">
<TextBlock Text="{Binding TitleShort}" />
<Button Content="X">
<Button.Style>
<Style TargetType="Button">
<Setter Property="Visibility" Value="Collapsed" />
<Style.Triggers>
<DataTrigger Binding="{Binding IsFocused, ElementName=Windows}" Value="True">
<Setter Property="Visibility" Value="Visible" />
</DataTrigger>
</Style.Triggers>
</Style>
</Button.Style>
</Button>
</StackPanel>
</DataTemplate>
</s:ComboBoxItemTemplateSelector.DropDownTemplate>
</s:ComboBoxItemTemplateSelector>
</ComboBox.ItemTemplateSelector>
<ComboBox.ItemContainerStyle>
<Style BasedOn="{StaticResource MaterialDesignComboBoxItemStyle}" TargetType="ComboBoxItem">
<Setter Property="ToolTip">
<Setter.Value>
<TextBlock Text="{Binding Title}" />
</Setter.Value>
</Setter>
</Style>
</ComboBox.ItemContainerStyle>
</ComboBox>
public class ComboBoxItemTemplateSelector : DataTemplateSelector
{
public DataTemplate SelectedTemplate { get; set; }
public DataTemplate DropDownTemplate { get; set; }
public override DataTemplate SelectTemplate(object item, DependencyObject container)
{
ComboBoxItem comboBoxItem = GetVisualParent<ComboBoxItem>(container);
if (comboBoxItem == null)
{
return SelectedTemplate;
}
return DropDownTemplate;
}
private static T GetVisualParent<T>(object childObject) where T : Visual
{
DependencyObject child = childObject as DependencyObject;
while ((child != null) && !(child is T))
{
child = VisualTreeHelper.GetParent(child);
}
return child as T;
}
}
ComboBox generates ComboBoxItem as a container for every item in its itemssource. You can bind to its properties with RelativeSource binding.
This should get you the expected behavior:
<Button Content="X">
<Button.Style>
<Style TargetType="Button">
<Setter Property="Visibility" Value="Collapsed" />
<Style.Triggers>
<DataTrigger Binding="{Binding IsMouseOver, RelativeSource={RelativeSource AncestorType=ComboBoxItem}}" Value="True">
<Setter Property="Visibility" Value="Visible" />
</DataTrigger>
</Style.Triggers>
</Style>
</Button.Style>
</Button>
I have an image that need to be showed based on condition, is that attachment file or not. The problem is, I've set trigger that set the value of the condition, but seems like the condition isn't work and the value always set to true.
<Image
Width="30"
Height="30"
Source="Resources/Images/chat_file_attach.png">
<Image.Style>
<Style TargetType="{x:Type Image}">
<Style.Triggers>
<DataTrigger Binding="{Binding AttachStat}" Value="False">
<Setter Property="Visibility" Value="Collapsed" />
</DataTrigger>
<DataTrigger Binding="{Binding AttachStat}" Value="True">
<Setter Property="Visibility" Value="Visible" />
</DataTrigger>
</Style.Triggers>
</Style>
</Image.Style>
</Image>
The question is. Is there any way to make the default value to false? I've set it to true on the C# looping data, whenever the condition is attachment included.
Take a look in your output window and search for:
System.Windows.Data Warning: 40 : BindingExpression path error
I think the AttachStat property is not available in the image's DataContext.
Use a single DataTrigger and make sure that the DataContext of the Image has a public AttachStat property:
<Image x:Name="img" Width="30" Height="30" Source="Resources/Images/chat_file_attach.png">
<Image.Style>
<Style TargetType="{x:Type Image}">
<Setter Property="Visibility" Value="Collapsed" />
<Style.Triggers>
<DataTrigger Binding="{Binding AttachStat}" Value="True">
<Setter Property="Visibility" Value="Visible" />
</DataTrigger>
</Style.Triggers>
</Style>
</Image.Style>
</Image>
img.DataContext = new YourClass();
...
public class YourClass : INotifyPropertyChanged
{
private bool _attachStat;
public bool AttachStat
{
get
{
return _attachStat;
}
set
{
_attachStat = value;
NotifyPropertyChanged();
}
}
public event PropertyChangedEventHandler PropertyChanged;
private void NotifyPropertyChanged([CallerMemberName] String propertyName = "")
{
if (PropertyChanged != null)
PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}
You can use a BoolToVisibilityConverter to convert a Boolean to and from a Visibility value.
In the resource section:
<BooleanToVisibilityConverter x:Key="BoolToVisibilityConverter" />
And the image:
<Image Width="30"
Height="30"
Source="Resources/Images/chat_file_attach.png"
Visibility="{Binding AttachStat,
Converter={StaticResource BoolToVisibilityConverter}}" />
I want the text in a TextBox to get selected when the TextBox gets focused.
Therefore I need to binding a Command to the "GotFocus" event. The special thing is, that the TextBox is created dynamically via an ItemsControl.
So there is a binding to the UserControl (View), the ItemsControl and the Item itself. When I tried to bind the UI element to the CommandParameter I just got the Model bindet to the current item in the ItemsControl.
All the bindings are working perfectly except the CommandParameter..
Somebody got an idea how to get this working?
Here is my code:
XAML
/////// <UserControl/> Information:
xmlns:i="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity"
x:Name="MainBindingControl"
///////
<ItemsControl ItemsSource="{Binding MySecondModelList }" Margin="10,10,10,0">
<ItemsControl.ItemsPanel>
<ItemsPanelTemplate>
<Grid helper:GridHelper.RowCount="{Binding MyFirstModel.Rows}" helper:GridHelper.ColumnCount="{Binding MyFirstModel.Columns}">
</Grid>
</ItemsPanelTemplate>
</ItemsControl.ItemsPanel>
<ItemsControl.ItemContainerStyle>
<Style>
<Setter Property="Grid.Row" Value="{Binding Row}" />
<Setter Property="Grid.Column" Value="{Binding Column}" />
</Style>
</ItemsControl.ItemContainerStyle>
<ItemsControl.ItemTemplate>
<DataTemplate>
<TextBox Margin="25,25,25,25" Height="30" Width="30" Text="{Binding Text, Mode=TwoWay, UpdateSourceTrigger=LostFocus}" TextAlignment="Center" VerticalContentAlignment="Center" >
<i:Interaction.Triggers>
<i:EventTrigger EventName="GotFocus">
<i:InvokeCommandAction Command="{Binding ElementName=MainBindingControl, Path=DataContext.TextBoxFocusCommand}" CommandParameter="{Binding RelativeSource={ RelativeSource Self }}"/>
</i:EventTrigger>
</i:Interaction.Triggers>
<TextBox.Style>
<Style TargetType="TextBox">
<Setter Property="Background" Value="OrangeRed" />
<Style.Triggers>
<Trigger Property="Text" Value="0">
<Setter Property="Background" Value="Orange" />
</Trigger>
<Trigger Property="Text" Value="1">
<Setter Property="Background" Value="White" />
</Trigger>
<Trigger Property="Text" Value="2">
<Setter Property="Background" Value="White" />
</Trigger>
<Trigger Property="Text" Value="3">
<Setter Property="Background" Value="White" />
</Trigger>
<Trigger Property="Text" Value="4">
<Setter Property="Background" Value="White" />
</Trigger>
</Style.Triggers>
</Style>
</TextBox.Style>
</TextBox>
</DataTemplate>
</ItemsControl.ItemTemplate>
</ItemsControl>
CS
#region TextBoxFocus
private ICommand _textBoxFocusCommand;
public ICommand TextBoxFocusCommand
{
get { return _textBoxFocusCommand; }
set { _textBoxFocusCommand = value; }
}
public void TextBoxFocus(object parameter)
{
var _tmp = parameter as TextBox;
if (_tmp != null )
{
_tmp.SelectAll();
}
}
#endregion
Models
public class FirstModel
{
public int Rows { get; set; }
public int Columns { get; set; }
}
public class SecondModel
{
public int Row { get; set; }
public int Column { get; set; }
public string Text { get; set; }
}
public class ViewModel
{
public FirstModel MyFirstModel { get; set; }
public ObservableCollection<SecondModel> MySecondModelList { get; set; }
}
Since what you want to do is only related to the view, I'd just add the code in the code-behind, instead of trying to use commands and get the TextBox inside the ViewModel. In MVVM you should NEVER reference UI assemblies from the ViewModel. But it is ok for you to use code-behind if what you are trying to do is only related to the View.
So, inside the style of the TextBox, you would have:
<EventSetter Event="GotFocus" Handler="TextBox_GotFocus"/>
And then in the code-behind of the UserControl:
private void TextBox_GotFocus(object sender, RoutedEventArgs e)
{
TextBox textBox = sender as TextBox;
textBox.SelectAll();
}
The complete code of your DataTemplate would then be:
<DataTemplate>
<TextBox Margin="25,25,25,25" Height="30" Width="30" Text="{Binding Text, Mode=TwoWay, UpdateSourceTrigger=LostFocus}" TextAlignment="Center" VerticalContentAlignment="Center" >
<!-- Just erase this block of code
<i:Interaction.Triggers>
<i:EventTrigger EventName="GotFocus">
<i:InvokeCommandAction Command="{Binding ElementName=MainBindingControl, Path=DataContext.TextBoxFocusCommand}" CommandParameter="{Binding RelativeSource={ RelativeSource Self }}"/>
</i:EventTrigger>
</i:Interaction.Triggers>-->
<TextBox.Style>
<Style TargetType="TextBox">
<EventSetter Event="GotFocus" Handler="TextBox_GotFocus"/>
<Setter Property="Background" Value="OrangeRed" />
<Style.Triggers>
<Trigger Property="Text" Value="0">
<Setter Property="Background" Value="Orange" />
</Trigger>
<Trigger Property="Text" Value="1">
<Setter Property="Background" Value="White" />
</Trigger>
<Trigger Property="Text" Value="2">
<Setter Property="Background" Value="White" />
</Trigger>
<Trigger Property="Text" Value="3">
<Setter Property="Background" Value="White" />
</Trigger>
<Trigger Property="Text" Value="4">
<Setter Property="Background" Value="White" />
</Trigger>
</Style.Triggers>
</Style>
</TextBox.Style>
</TextBox>
</DataTemplate>
Notice that the method SelectAll() of the TextBox called on GotFocus event has a little trick to work as intended. Check this SO question: How to automatically select all text on focus in WPF TextBox?
I've following code in my WPF app.I'm trying to set the focus on a textbox on a button click...i.e. on invoking Check() method...
Code:
MainWindowResources.xaml
<Style TargetType="TextBox" x:Key="MyFiedlStyle">
<Style.Triggers>
<DataTrigger Binding="{Binding Path=FocusOnMyField}" Value="true">
<Setter Property="FocusManager.FocusedElement" Value="{Binding ElementName=myField}"/>
</DataTrigger>
</Style.Triggers>
</Style>
MainWindow.xaml
<TextBox HorizontalAlignment="Left" Margin="1,1,0,0" Width="180" Text="{Binding MyAttributes.MyFieldValue}" TabIndex="4" Grid.Row="3" VerticalAlignment="Top" Grid.Column="5"
Name="myField" Style="{DynamicResource MyFieldStyle}"/>
MainWindowViewModel
private bool FocusOnMyField
{
get { return m_FocusOnMyField; }
set
{
m_FocusOnMyField = value;
OnPropertyChanged("FocusOnMyField");
}
}
private void Check()
{
this.FocusOnSecDescription = true;
}
Thanks.
I have a PCL and I am using MVVM pattern.
I am building a togglebutton, that toggles when the related property in the viewmodel is activated, with behaviors and triggers.
This is my behavior
public class ToggleBehavior : Behavior<View>
{
TapGestureRecognizer tapRecognizer;
public static readonly BindableProperty IsToggledProperty = BindableProperty.Create<ToggleBehavior, bool>(tb => tb.IsToggled, false);
public bool IsToggled
{
set { SetValue(IsToggledProperty, value); }
get { return (bool)GetValue(IsToggledProperty); }
}
}
This is how I consume my behavior
<Button Text="AUTO" Style="{StaticResource SmallEllipseButton}" BackgroundColor="{StaticResource BackgroundColor}" cm:Message.Attach="Automatic($dataContext)">
<Button.Behaviors>
<local:ToggleBehavior x:Name="autoToggleBehavior" IsToggled="{Binding CurrentMode,Converter={StaticResource modeToBooleanConverter}, ConverterParameter=AUTO}"/>
</Button.Behaviors>
<Button.Triggers>
<DataTrigger TargetType="Button" Binding="{Binding Source={x:Reference autoToggleBehavior},Path=IsToggled}" Value="False" >
<Setter Property="BackgroundColor" Value="White"/>
<Setter Property="BorderColor" Value="White"/>
<Setter Property="TextColor" Value="Gray"/>
</DataTrigger>
<DataTrigger TargetType="Button" Binding="{Binding Source={x:Reference autoToggleBehavior},Path=IsToggled}" Value="True" >
<Setter Property="BackgroundColor" Value="{StaticResource BackgroundColor}"/>
<Setter Property="TextColor" Value="White"/>
</DataTrigger>
</Button.Triggers>
</Button>
The problem is that the property IsToggled is not binded correctly in this IsToggled="{Binding CurrentMode,Converter={StaticResource modeToBooleanConverter}, ConverterParameter=AUTO}"/>
If I set it statically to true or false it works.
The problem I think is that I can't bind dinamically this property.
I use the same binding with the same converter in the same page for an IsVisible property and it works.
If I put a breakpoint in the converter, the application doesn't break in it, but for the IsVisible property breaks.
Using a Button might not be the best option as it already has a tap handler and assigning one to it would still not trigger the event. I don't know if this helps but I changed the control to a Label to get the below to work. Of course if the Button is bound to a command that modifies the view model then you don't need the tap handler in the behaviour at all.
XAML:
<?xml version="1.0" encoding="utf-8"?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms" xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml" xmlns:local="clr-namespace:BehTest" x:Class="BehTest.BehTestPage">
<Label Text="AUTO" HorizontalOptions="Center" VerticalOptions="Center">
<Label.Behaviors>
<local:ToggleBehavior x:Name="autoToggleBehavior" IsToggled="{Binding Toggled, Mode=TwoWay}"/>
</Label.Behaviors>
<Label.Triggers>
<DataTrigger TargetType="Label" Binding="{Binding Source={x:Reference autoToggleBehavior},Path=IsToggled}" Value="False" >
<Setter Property="BackgroundColor" Value="White"/>
<Setter Property="TextColor" Value="Gray"/>
</DataTrigger>
<DataTrigger TargetType="Label" Binding="{Binding Source={x:Reference autoToggleBehavior},Path=IsToggled}" Value="True" >
<Setter Property="BackgroundColor" Value="Blue"/>
<Setter Property="TextColor" Value="White"/>
</DataTrigger>
</Label.Triggers>
</Label>
</ContentPage>
Behaviour:
public class ToggleBehavior : Behavior<View>
{
readonly TapGestureRecognizer tapRecognizer;
public ToggleBehavior()
{
tapRecognizer = new TapGestureRecognizer
{
Command = new Command(() => this.IsToggled = !this.IsToggled)
};
}
public static readonly BindableProperty IsToggledProperty = BindableProperty.Create<ToggleBehavior, bool>(tb => tb.IsToggled, false);
public bool IsToggled
{
set { SetValue(IsToggledProperty, value); }
get { return (bool)GetValue(IsToggledProperty); }
}
protected override void OnAttachedTo(View bindable)
{
base.OnAttachedTo(bindable);
bindable.GestureRecognizers.Add(this.tapRecognizer);
}
protected override void OnDetachingFrom(View bindable)
{
base.OnDetachingFrom(bindable);
bindable.GestureRecognizers.Remove(this.tapRecognizer);
}
protected override void OnAttachedTo(BindableObject bindable)
{
base.OnAttachedTo(bindable);
this.BindingContext = bindable.BindingContext;
bindable.BindingContextChanged += Bindable_BindingContextChanged;
}
protected override void OnDetachingFrom(BindableObject bindable)
{
base.OnDetachingFrom(bindable);
this.BindingContext = null;
bindable.BindingContextChanged -= Bindable_BindingContextChanged;
}
void Bindable_BindingContextChanged(object sender, EventArgs e)
{
var bobject = sender as BindableObject;
this.BindingContext = bobject?.BindingContext;
}
}
We added a ToggleButton into our NuGet!
Its free to use.
xmlns:aw="clr-namespace:AscendantWare.Xamarin.Essentials.Controls"
<aw:AWToggleButton TextColor="White" ToggleBackgroundColor="DarkGoldenrod" Margin="0" VerticalOptions="FillAndExpand" HorizontalOptions="Fill" CornerRadius="15" IsToggled="{Binding IsNoteEnabled, Mode=TwoWay}" Command="{Binding MyCommand}"/>
More Informations in our online documentation here!