Is Style Inheritence with nested User Controls Possible In WPF? - wpf

I'm pretty sure it's not possible to use BasedOn with regards to a Style declaration in a nested UserControl, and be able to reference a Style declaration made in a parent UserControl - can anyone confirm this?
I've tried BasedOn="{StaticResource}" and BasedOn="{DynamicResource}" and neither work.
(Pseudo code sample below)
<Window>
<UserControl>
<StackPanel>
<StackPanel.Resources>
<Style TargetType="{x:Type Button}">
<Setter Property="Background" Value="Red" />
</Style>
</StackPanel.Resources>
<UserControl2> <!--this will reside in a different .xaml file...-->
<Button Content="Hello World">
<Button.Style>
<Style TargetType="{x:Type Button}" BasedOn="????">
<!--is this possible to inherit the red background?-->
<Setter Property="Padding" Value="10" />
</Style>
</Button.Style>
</Button>
</UserControl2>
</StackPanel>
</UserControl

Related

How to make an exception for Application.Resources style in a specific Grid.Resources

I am doing small WPF app for my own using Visual Studio, C#, .NET Standard and WPF in this specific project.
I have defined style for all TextBlocks and TextBoxes in Applications.Resources like below.
<Application.Resources>
<Style TargetType="TextBox">
<Setter Property="FontSize" Value="10"/>
</Style>
<Style TargetType="TextBlock">
<Setter Property="FontSize" Value="10"/>
</Style>
</Application.Resources>
Then in main window I have a grid which contains some buttons.
<Grid>
<Grid.Resources>
<Style TargetType="Button">
<Setter Property="FontSize" Value="50" />
</Style>
<Style TargetType="TextBlock">
<Setter Property="FontSize" Value="50"/>
</Style>
</Grid.Resources>
<Button Grid.Column="0" Content="DASHBOARD" Command="local:CustomCommands.ShowDashboard"/>
</Grid>
I would like to set for the textblocks/textboxes in this specific buttons a wider font.
I tried for many different syntax but could not manage it. I tried also do define x:Key for this style in Grid.Resources and use it in this specific Button control. This wasn't work either.
Can anyone let me know which way should I let know my application that text in this buttons would have bigger font size?
The TextBlock created for string contents by the ContentPresenter inside the Button template doesn't apply the locally-defined resources, i.e. those in your Grid.
The easiest way to solve your problem would be to explicitly define a TextBlock as the Button's content.
<Grid>
<Grid.Resources>
<Style TargetType="TextBlock">
<Setter Property="FontSize" Value="50"/>
</Style>
</Grid.Resources>
<Button Grid.Column="0" Command="local:CustomCommands.ShowDashboard">
<TextBlock Text="DASHBOARD" />
</Button>
</Grid>

Override property of custom style

I have Style that applies to all of the buttons of my application:
<Style TargetType="Button" BasedOn="{StaticResource {x:Type Button}}">
<Setter Property="Background" Value="Red" />
<Setter Property="Foreground" Value="Black" />
<Setter Property="FontSize" Value="16" />
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="Button">
<Grid>
<Ellipse x:Name="StatusButtonCircle" Stroke="Black" StrokeThickness="0" Fill="AliceBlue" Stretch="Uniform">
<Ellipse.Width>
<Binding ElementName="StatusButtonCircle" Path="ActualHeight"/>
</Ellipse.Width>
</Ellipse>
<Ellipse x:Name="StatusButtonCircleHighlight" Margin="4" Stroke="Black" StrokeThickness="2" Stretch="Uniform">
<Ellipse.Width>
<Binding ElementName="StatusButtonCircleHighlight" Path="ActualHeight"/>
</Ellipse.Width>
</Ellipse>
<ContentPresenter HorizontalAlignment="Center"
VerticalAlignment="Center"/>
</Grid>
<ControlTemplate.Triggers>
... some Triggers here
</ControlTemplate.Triggers>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
How can I change properties (e.g. FontWeight, FontSize etc.) in XAML? I tried this:
<Button FontWeight="Bold" FontSize="30" Foreground="Red">
</Button>
In the designer-view, I see the changes. But during runtime those changes are not applied.
After some investigation, I also have a Style for all TextBlock like this:
<Style TargetType="{x:Type TextBlock}">
<Setter Property="FontSize" Value="16" />
<Setter Property="FontFamily" Value="Segoe UI Semibold" />
<Setter Property="Foreground" Value="White" />
</Style>
This Style seems to override the TextBlock that is used on the Button. I still can't change the Text Properties in XAML.
Here's what it looks like if I use the Styles above in an empty project:
In the designer, the changes are applied, during runtime the one from the TextBlock are applied. If I assign a x:Key to the TextBlock, it works fine. But then I have to assign this Style to every TextBlock used in the app manually.
You are facing typical style inheritance issue in wpf.
A control looks for its style at the point when it is being initalized. The way the controls look for their style is by moving upwards in logical tree and asking the logical parent if there is appropriate style for them stored in parent's resources dictionary.
In your case, you are using ContentPresenter in button as a default behaviour. and it is using TextBlock to represent text in button by default.
Therefore at the time of initialization, ContentPresenter finding TextBlock style and applying to represent content in button.
If you want to restrict ContentPresenter to look for the style then you have to bind a blank style to content presenter so that it will not look for any further style.
<Style TargetType="Button" BasedOn="{StaticResource {x:Type Button}}">
<Setter Property="Background" Value="Red" />
<Setter Property="Foreground" Value="Black" />
<Setter Property="FontSize" Value="16" />
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="Button">
<Grid>
<Ellipse x:Name="StatusButtonCircle" Stroke="Black" StrokeThickness="0" Fill="AliceBlue" Stretch="Uniform">
<Ellipse.Width>
<Binding ElementName="StatusButtonCircle" Path="ActualHeight"/>
</Ellipse.Width>
</Ellipse>
<Ellipse x:Name="StatusButtonCircleHighlight" Margin="4" Stroke="Black" StrokeThickness="2" Stretch="Uniform">
<Ellipse.Width>
<Binding ElementName="StatusButtonCircleHighlight" Path="ActualHeight"/>
</Ellipse.Width>
</Ellipse>
<ContentPresenter HorizontalAlignment="Center"
VerticalAlignment="Center">
<ContentPresenter.Resources>
<Style TargetType="TextBlock" BasedOn="{x:Null}"/>
<!-- Assigned Blank style here therefore it will not search for any further style-->
</ContentPresenter.Resources>
</ContentPresenter>
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
You can do it with the BasedOn. I show you an example.
<Window.Resources>
<Style TargetType="ToggleButton" BasedOn="{StaticResource DefToggleButton}">
<Setter Property="FontWeight" Value="Bold"/>
<Setter Property="Content" Value="Some Cool Stuff"/>
<Style.Triggers>
<Trigger Property="IsChecked" Value="True">
<Setter Property="Content" Value="More Stuff"/>
</Trigger>
</Style.Triggers>
</Style>
</Window.Resources>
Here in my resources I have DefToggleButton, now in my xaml file I can set up any Property according to my need (which in this case is the FontWeight and Content Property).
I think if you remove the Template from your Style, then you can do what you want to do, like this:
<Window.Resources>
<Style TargetType="Button" x:Key="stBtn>
<Setter Property="Background" Value="Blue" />
<Setter Property="Foreground" Value="White" />
<Setter Property="FontFamily" Value="Segoe UI Semibold" />
</Style>
</Window.Resources>
The Template that you have says, that all Buttons should be shown as a Border with a ContentPresenter inside, which is not what you have asked.
Without the Template, you can define your Buttons like this:
<Button Content="Hi!" Style="{StaticResource stBtn}" Foreground="Red" >
Like this, you have a Blue Button with Red Foreground.
=================
Edit
So what if you define a Template, and use it in you style, like this?
Then, by TemplateBinding you can define that the Foreground and teh Content come later, when the Button is actually defined.
<Window.Resources>
<ControlTemplate x:Key="ctBtn" TargetType="{x:Type Button}">
<Label Background="Green" Content="{TemplateBinding Content}" Foreground="{TemplateBinding Foreground}"/>
</ControlTemplate>
<Style x:Key="stBtn2" TargetType="{x:Type Button}">
<Setter Property="Template"
Value="{StaticResource ctBtn}" />
</Style>
<Window.Resources>
Then by defining the Button:
<Button Content="Hi!" Style="{StaticResource stBtn2}" Foreground="Red" >
===============
Edit2
So the general idea is that you can define a TemplateBinding for the properties of the elements in your template. So for example,you have an Ellipse in your template:
<Ellipse Fill="{TemplateBinding BorderBrush}" />
This defines that the Fill property of your Ellipse comes from the BorderBrush of your Button (Assuming that the template is targeting a Button)
Accordingly, you can put a Label in your Template, and set a TemplateBinding for its Forground and FontWeight property.
<Label Foreground="{TemplateBinding Foreground}" />
First, for this issue to be reproduced, Styles need to be set within a ResourceDictionary which is then added to Application.Resources (precisellyTextBlock global style). Setting Styles within for example Window.Resources will not reproduce the issue.
Global TextBlock Style is applied to the TextBlock created by ConentPresenter
As noticed in the question, the issue is that the global (keyless) Style for TextBlock is applied to the TextBlock created by ContentPresenter when it concludes the content to display is a string. For some reason this doesn't happen when that Style is defined within Window.Resources. As it turns out, there is more to this than just "controls are looking for their styles within their parent's resources".
ControlTemplate is a boundary for elements not deriving from Control class
For TextBlock (which doesn't derive from Control class, but from UIElement) within ControlTemplate, it means that wpf will not look for it's implicit Style beyond it's templated parent. So it won't look for implicit Style within it's parent's resources, it will apply application level implicit Style found within Application.Resources.
This is by design (hardcoded into FrameworkElement if you will), and the reason is exactly to prevent issues like this one. Let's say you're creating a specific Button design (as you are) and you want all buttons in your application to use that design, even buttons within other ControlTemplates. Well, they can, as Button does derive from Control. On the other hand, you don't want all controls that use TextBlock to render text, to apply the implicit TextBlock Style. You will hit the same issue with ComboBox, Label... as they all use TextBlock, not just Button.
So the conclusion is: do not define global Style for elements which don't derive from Control class within Application.Resources, unless you are 100% sure that is what you want (move it to Window.Resources for example). Or, to quote a comment I found in source code for MahApps.Metro UI library: "never ever make a default Style for TextBlock in App.xaml!!!". You could use some solution to style the TextBlock within your Button's ControlTemplate, but then you'll have to do it for Label, ComboBox, etc... So, just don't.

How do buttons style optimize in XAML code?

<Style x:Key="ToolBarButton" TargetType="{x:Type Button}">
<Setter Property="Control.Background" Value="#00000000"/>
<Setter Property="Control.Width" Value="25"/>
<Setter Property="Control.Height" Value="25"/>
</Style>
...
<Grid HorizontalAlignment="Left">
<Button Style="{StaticResource ToolBarButton}"/>
<Button Style="{StaticResource ToolBarButton}"/>
<Button Style="{StaticResource ToolBarButton}"/>
<Button Style="{StaticResource ToolBarButton}"/>
<Button Style="{StaticResource ToolBarButton}"/>
<Button Style="{StaticResource ToolBarButton}"/>
</Grid>
I wanna optimize my XAML code. I don't wanna assign a style to each button, but I wish every button to have my style.
Is it possible to do something like this? Only working ... :)
<Grid x:Name="gToolBar" Grid.Row="1" HorizontalAlignment="Left" Style="{StaticResource ToolBarButton}">
<Button/>
<Button/>
<Button/>
<Button/>
<Button/>
<Button/>
</Grid>
I don't use TargetType only, because I have other buttons with different styles.
I think it available, but i don't know how.
Thanks...
As i already said everything that is to be done in the comment, but for further clarification:
I wanna optimize my XAML code. I don't wanna assign a style to each button, but I wish every button to have my style.
Move the Style part to <Application.Resources> in App.xaml file, Like shown below:
<Application.Resources>
<Style TargetType="Button" >
<Setter Property="Control.Background" Value="#00000000"/>
<Setter Property="Control.Width" Value="25"/>
<Setter Property="Control.Height" Value="25"/>
</Style>
</Application.Resources>
Note: I've removed the x:Key part. Now this will apply to all the button's that is in the application.
I don't use TargetType only, because I have other buttons with different styles. I think it available, but i don't know how.
For this you would have to make a custom button as a UserControl, thus making them completely different from a usual Button. Apply styling to them in their own UserControl.Resources. Thus styling mentioned in App.Resources won't affect these custom made UserControls
You can create a default style for buttons within the grid:
<Window ...>
<Window.Resources>
<Style x:Key="ToolBarButton" TargetType="{x:Type Button}">
<Setter Property="Control.Background" Value="#00000000"/>
<Setter Property="Control.Width" Value="25"/>
<Setter Property="Control.Height" Value="25"/>
</Style>
</Window.Resources>
<Grid HorizontalAlignment="Left">
<Grid.Resources>
<Style x:Key="{x:Type Button}" BasedOn="{StaticResource ToolBarButton}" TargetType="{x:Type Button}"></Style>
</Grid.Resources>
<Button />
<Button />
<Button />
<Button />
<Button />
<Button />
</Grid>
</Window>
If you create a resource that uses a control type as key within a container, the style will get applied to all controls of the type within the container. If you want to define the original style somewhere else (for example because you use it in many place) you can base the local style off the global style.
You should use application resources to do that. add this code to there(app.xaml):
<Application.Resources>
<Style TargetType="Button" >
<Setter Property="Control.Background" Value="#00000000"/>
<Setter Property="Control.Width" Value="25"/>
<Setter Property="Control.Height" Value="25"/>
</Style>
</Application.Resources>
UPDATE
Or if you want this style apply just some part of your application such some special 'Grid' or special Window ..., just put it inside Resource of that element like this:
<Grid>
<Grid.Resources>
<Style TargetType="Button" >
<Setter Property="Control.Background" Value="#00000000"/>
<Setter Property="Control.Width" Value="25"/>
<Setter Property="Control.Height" Value="25"/>
</Style>
</Grid.Resources>
... inside code, and your buttons which we eant to apply style for them.
</Grid>

Extend UserControl.Resources

I want to provide a simple default style for a UserControl, but still be able to extend or override the style when using the control. Below is a sample scenario with a simple UserControl and a Window containing the control. The intention is for the style for the Button provided in the Window to override the default style defined in the UserControl.
UserControl
<UserControl x:Class="Sample.TestControl" ... >
<UserControl.Resources>
<Style TargetType="{x:Type Button}">
<Setter Property="Margin" Value="2" />
<Setter Property="Foreground" Value="Orange" />
</Style>
<Style TargetType="{x:Type StackPanel}">
<Setter Property="Background" Value="Black" />
</Style>
</UserControl.Resources>
<StackPanel>
<Button Content="Press Me" />
<Button Content="Touch Me" />
<Button Content="Tap Me" />
</StackPanel>
</UserControl>
Window
<Window x:Class="Sample.MainWindow" ... >
<Grid>
<local:TestControl>
<local:TestControl.Resources>
<Style TargetType="{x:Type Button}">
<Setter Property="Margin" Value="2" />
<Setter Property="Foreground" Value="Green" />
</Style>
</local:TestControl.Resources>
</local:TestControl>
</Grid>
</Window>
Problem
The above code will result in:
Exception: Set property 'System.Windows.ResourceDictionary.DeferrableContent' threw an exception.
InnerException: Item has already been added.
The above code is trying to submit two styles with the same key into the same ResourceDictionary, so obviously it wasn't going to work. My guess that I am not going to be able to provide a default style for the buttons...
Insufficient Workaround: Override default ResourceDictionary
<Window x:Class="Sample.MainWindow" ... >
<Grid>
<local:TestControl>
<local:TestControl.Resources>
<ResourceDictionary>
<Style TargetType="{x:Type Button}">
<Setter Property="Margin" Value="2" />
<Setter Property="Foreground" Value="Green" />
</Style>
</ResourceDictionary>
</local:TestControl.Resources>
</local:TestControl>
</Grid>
</Window>
By putting the custom Button style in a ResouceDictionary, I can override the default one. However, its not just overriding the Button style, its overriding all of the resources. So, the StackPanel will no longer have a black background. (obviously I could add that to the overriding style as well, but thats not practical on a bigger scale.)

WPF - Use control inheritance for standard-styled controls?

I have a WPF application with many windows and user controls, and I'd like to implement standard styles for certain controls that appear throughout the application. As an example, say I need two standard TextBlocks throughout the application: one for large headings, one for small headings. And the only difference between them is the font size, say 36 and 24 respectively. All other properties (color, fontfamily, etc.) could be set by a TextBlock template or global TargetType="{x:Type TextBlock}" styles.
Of course I could create two global named styles that just set the font size and apply those staticresource styles liberally throughout the XAML to my TextBlocks, or at the highest possible level above the TextBlocks that would not interfere with other TextBlocks. But as an alternative, which would remove the requirement for setting the Style tag in many places, is inheriting from TextBlock is a good way to go?
TextBlock controls:
class TextBlockLargeHeading : TextBlock
{
public TextBlockLargeHeading()
{ }
}
class TextBlockSmallHeading : TextBlock
{
public TextBlockSmallHeading()
{ }
}
Global resource:
<Application.Resources>
<Style TargetType="TextBlock">
<Setter Property="Foreground" Value="Red" />
</Style>
<Style TargetType="MyApp:TextBlockLargeHeading" BasedOn="{StaticResource {x:Type TextBlock}}" >
<Setter Property="FontSize" Value="36" />
</Style>
<Style TargetType="MyApp:TextBlockSmallHeading" BasedOn="{StaticResource {x:Type TextBlock}}" >
<Setter Property="FontSize" Value="24" />
</Style>
</Application.Resources>
Then, to use them anywhere, simply reference the custom textblocks:
<StackPanel>
<MyApp:TextBlockLargeHeading Text="Large" />
<MyApp:TextBlockSmallHeading Text="Small" />
</StackPanel>
Which would create two Red TextBlocks with the appropriate font sizes.
Is this a reasonable approach? Are there any gotcha's if I've got 100's of instances of these, maintainability-wise or otherwise? Is there a better (safer or less code/XAML) approach? Perhaps using User Controls instead?
Thanks!
There's no reason to do all that. Create your styles and use them directly.
....
<Style x:Key="DefaultTextBlockStyle" TargetType="TextBlock">
<Setter Property="Foreground" Value="Red" />
<Setter Property="FontSize" Value="24" />
</Style>
<Style x:Key="LargeTextBlockStyle" TargetType="TextBlock" BasedOn="{StaticResource DefaultTextBlockStyle}">
<Setter Property="FontSize" Value="36" />
</Style>
<!-- Style applies to all TextBoxes -->
<Style TargetType="{x:Type TextBlock}" BasedOn="{StaticResource DefaultTextBlockStyle}" />
...
<StackPanel>
<TextBlock Text="Large" Style="{StaticResource LargeTextBlockStyle}"/>
<TextBlock Text="Small"/>
</StackPanel>

Resources