Develop Reference

C# WPF - Disabled ComboBox should look like label

I'm trying to change the style of my combobox in wpf when it's disabled. It should look like a plain text (label).
Here is my code:
<Style TargetType="{x:Type ComboBox}">
<Style.Triggers>
<Trigger Property="IsEnabled" Value="false">
<Setter Property="Foreground" Value="Black" />
<Setter Property="BorderBrush" Value="Black" />
<Setter Property="BorderThickness" Value="0"></Setter>
<Setter Property="Background" Value="{x:Null}" />
</Trigger>
</Style.Triggers>
</Style>
but it doesnt seem to work.
any hints?

You can add ControlTemplate, so the combobox will shown like a
TextBox(without border, background, toggle button, ect.). but it act
as a combobx(having drop-down list). Drop-down will not shown if the
control is disbled(hence it will shown like a label)
<ComboBox.Template>
<ControlTemplate>
<TextBlock Text="{Binding SelectedItem.MyText,RelativeSource={RelativeSource Mode=TemplatedParent}}"></TextBlock>
</ControlTemplate>
</ComboBox.Template>

If the control has a tendency to look like another control on certain condition, this kind of requirement can be satisfied by ContentControl. You can switch to appropriate content based on a given condition.
<ContentControl IsEnabled="True" /> // or IsEnabled="False"
Then switch via Style..
<Style TargetType="{x:Type ContentControl}">
<Style.Triggers>
<Trigger Property="IsEnabled" Value="true">
// combobox
</Trigger>
<Trigger Property="IsEnabled" Value="false">
// Label
</Trigger>
</Style.Triggers>
</Style>

Just place two controls, the ComboBox and the Label. Bind the Visibility property of each to your boolean indicating if the ComboBox should be enabled so that one is visible when enabled and the other when disabled.

DataGrid -- AlternatingRowBackground color interfering with "IsMouseOver" color

I have a DataGrid that uses AlternatingRowBackground to make itself easier to read. In that same grid I also have a background color change for rows based on a "IsMouseOver" Setter Property in my App.xaml file. The problem that I am having is that the rows that have the alternating color (they are not white), do not change to the "IsMouseOver" color when the mouse hovers over it. Basically the AlternatingRowBackground color is taking precedence over my RowStyle. How do I make it so that the colored rows change as well when the mouse hovers over them?
App.xaml:
<!-- DataGrid Row Style -->
<Style x:Key="RowStyleWithAlternation" TargetType="DataGridRow">
<Setter Property="SnapsToDevicePixels" Value="True" />
<Setter Property="Background" Value="GhostWhite"/>
<Setter Property="FontWeight" Value="Normal"/>
<Setter Property="ContextMenu" Value="{x:Null}"/>
<Style.Triggers>
<Trigger Property="AlternationIndex" Value="1">
<Setter Property="Background" Value="#FFD0D0E0"/>
</Trigger>
<Trigger Property="IsMouseOver" Value="True">
<Setter Property="Background" Value="Purple"/>
</Trigger>
<Trigger Property="IsSelected" Value="True">
<Setter Property="Background" Value="#F9F99F" />
</Trigger>
</Style.Triggers>
</Style>
User Control xaml:
<DataGrid ... AlternatingRowBackground="Gray" RowStyle="{StaticResource RowStyleWithAlternation}" ... />

It works if you change your UserControl.xaml as follows:
<DataGrid RowStyle="{StaticResource RowStyleWithAlternation}" AlternationCount="2" />
The background is set through the AlternationIndex Trigger on your row which takes no priority over the IsMouseOver.
I've found the answer on this post:
WPF Style Trigger for DataGridRow Background Color Trumped by AlternatingRowBackground Brush

Design responding Triggers, defining and using WPF

Recently I read about styles and control templates. As it says control templates are responsible for whole control design. But, I want for example to change only SPECIFIC part of the default control template, for example when mouse is over, or control has focus, when I wrote this:
<Style x:Key="StyleTextBox" TargetType="TextBox">
<Setter Property="Margin" Value="5, 0"/>
<Setter Property="VerticalContentAlignment" Value="Center"/>
<Setter Property="HorizontalContentAlignment" Value="Left"/>
<Setter Property="BorderBrush" Value="Black"/>
<Setter Property="Background" Value="Transparent"/>
<Setter Property="SelectionBrush" Value="#CCFBE6D9"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate>
<ControlTemplate.Triggers>
<Trigger Property="IsMouseOver" Value="True">
<Setter Property="BorderBrush" Value="Black" />
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
..whole template got overridden... and its kinda not cool...
So how to change only isMouseOver visual style, without overriding the whole default style?

The whole template got replaced because your XAML says, "set the Template to this ControlTemplate that I'm declaring right here." Problem is, your template is empty. Use a template when you want to tell WPF, "represent the control using this visual tree". You gave it an empty visual tree and got exactly what you asked for ;).
In this case, however, your intention isn't to change the visual structure of the control; you just want to change a property. You can still use a Trigger and Setter for this, but you need not create a template to do so. A Style has its own collection of triggers, so you can just move it there:
<Style x:Key="StyleTextBox" TargetType="TextBox">
<Setter Property="Margin" Value="5, 0"/>
<Setter Property="VerticalContentAlignment" Value="Center"/>
<Setter Property="HorizontalContentAlignment" Value="Left"/>
<Setter Property="BorderBrush" Value="Black"/>
<Setter Property="Background" Value="Transparent"/>
<Setter Property="SelectionBrush" Value="#CCFBE6D9"/>
<Style.Triggers>
<Trigger Property="IsMouseOver" Value="True">
<Setter Property="BorderBrush" Value="Black" />
</Trigger>
</Style.Triggers>
</Style>
This works because you're just changing a property of the styled control; generally, you can expect templates to honor the top-level properties of the controls to which the template is applied. For example, the default TextBox template should ensure that the TextBox is drawn with a background conforming to the templated parent's Background property.
Triggers on templates are more useful in cases where you want to manipulate a specific sub-element declared within a custom template.

Disable the "IsEnabled=false" Color Change on a Button?

I want to Avoid the Color Change of a Button when it gets disabled.
The Button Color should be the Same if its diabled or not.
Using a style I can change the Background Color when it gets disabled:
<Style TargetType="{x:Type Button}">
...
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type Button}">
...
<ControlTemplate.Triggers>
...
<Trigger Property="IsEnabled" Value="false">
<Setter TargetName="Border" Property="Background" Value="#EEEEEE" />
<Setter TargetName="Border" Property="BorderBrush" Value="#AAAAAA" />
<Setter Property="Foreground" Value="#888888"/>
</Trigger>
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
I can change the Background color there, but I want to keep it dynamic because the Background Color is databound and should not change.
If I delete the Background setter, the default background color change is performed.
How can I disable the colorchange? Or at least make the Disabled-Background-Color databound?
Sorry for my bad english.

If you want to make it data-bonund most appropriate place, imo, is declaring it inside relative DataTmplate of your control, where you specify the Style (already defined by you) and data applied to the control.
There you can define a Converter between some your state and relative color you would like to appear on the button.
OR
If you would like to limit yourself in Style, you can define a databinding inside Style itself. Imo not very logical, but it is possible.
Have a look on this answer:
Change Button Background color through MVVM pattern in WPF

I know this is late but hopefully it helps someone. This is how I would setup the style:
<Style TargetType="Button">
...
<Style.Triggers>
<Trigger TargetType="Button" Property="IsEnabled" Value="false">
<Setter TargetName="Border" Property="Background" Value="#EEEEEE" />
<Setter TargetName="Border" Property="BorderBrush" Value="#AAAAAA" />
<Setter Property="Foreground" Value="#888888"/>
</Trigger>
</Style.Triggers>
</Style>
You need to include the TargetType again in the Trigger or else you'll get an exception.

Unable to style WPF ComboBox on Mouse Hover

Does anyone know how to style the background property of a WPF ComboBox when a mouse is hovering on top of it?
I cannot get rid of the blue-ish button like background off the ComboBox.

You can style it like anything else:
<Style TargetType="{x:Type ComboBox}" x:Key="HoverBox">
<Style.Triggers>
<Trigger Property="IsMouseOver" Value="True">
<Setter Property="Background" Value="Blue" />
</Trigger>
</Style.Triggers>
</Style>
usage:
<ComboBox Style="{StaticResource HoverBox}" ... />
And at the top of your UserControl/ Window you have to place the style:
<UserControl...>
<UserControl.Resources>
<Style TargetType="{x:Type ComboBox}" x:Key="HoverBox">
<Style.Triggers>
<Trigger Property="IsMouseOver" Value="True">
<Setter Property="Background" Value="Blue" />
</Trigger>
</Style.Triggers>
</Style>
</UserControl.Resources>
[CONTENT HERE]
</UserControl>

It will not work.Its because of the default control template of ComboBox.You may need to override the default template for this behavior.Have a look at
MouseOver highlighting style returning to default after a second (Caused by Aero?)
http://social.expression.microsoft.com/Forums/en/blend/thread/b210978c-24e8-431b-916b-a40a752b990c
http://social.msdn.microsoft.com/Forums/en/wpf/thread/a18891e9-8879-4819-9679-247341782f60