WPF Stackpanel spacing between custom controls - wpf

how is it possible to get a space between some custom controls inside a stackpanel? I did it right before with a Textbox, Button, and so on, but i cannot do it with a custom control.
That's the code i've got so far
<Grid>
<StackPanel x:Name="spTasks" CanVerticallyScroll="True">
<StackPanel.Resources>
<Style TargetType="local:SmartTaskOverview">
<Setter Property="Margin" Value="50,50,50,50" />
</Style>
</StackPanel.Resources>
</StackPanel>
</Grid>
Thanks for your help

FrameworkElements and their sub-classes don't just look for a resource using the controls type, they use the value of DefaultStyleKey. It's common practice for most sub-classes of Control (and some other FrameworkElements) to override the default value of this dependency property in the static constructor to be the type of the control, but sub-classes of UserControl usually don't bother.
static Foo()
{
DefaultStyleKeyProperty.OverrideMetadata(typeof(Foo), new FrameworkPropertyMetadata(typeof(Foor));
}
If you didn't do this in your SmartTaskOverview then it will be looking for its default style using typeof(UserControl) as the resource key and not typeof(SmartTaskOverview).
Note: The UserControl will require a control template to show its children, this is normally provided by the default style for UserControl but by changing the key it will find your default style instead. To resolve this, just base your style on the UserControl style.
<Style TargetType="local:SmartTaskOverview" BasedOn="{StaticResource {x:Type UserControl}}">
<Setter Property="Margin" Value="50,50,50,50" />
</Style>
Alternatively you could provide a simple template yourself.
<Style TargetType="local:SmartTaskOverview">
<Setter Property="Margin" Value="50,50,50,50" />
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type local:SmartTaskOverview}">
<ContentPresenter />
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>

Related

Stop child from inheriting parent Style in TabControls

In my WPF application i have a TabControl that i am binding to a style i created:
On my View:
<TabControl Grid.Row="6" Style="{DynamicResource SideBarTabControl}">
On a separate ResourceDictionary:
<Style x:Key="SideBarTabControl" TargetType="{x:Type TabControl}" BasedOn="{StaticResource {x:Type TabControl}}" >
<Setter Property="FontSize" Value="{DynamicResource TitleFontSize}"/>
</Style>
So far so good, things work as expected. The problem is that now all the children of this TabControl, such as a ListView inside a TabItem, is also getting the same FontSize as the TabControl, instead of the default.
I thought that by specifying TargetType="{x:Type TabControl}" i would stop the style from being applied to children of different types. What i'm looking for is to actually stop it from affecting EVERYTHING BUT the component that explicitly inherited the style. So how can this be done? I think i am missing something simple...
If i override the font size in my ListView it works, but this means i have to do it for every child, which might become very cumbersome.
I have read this and other questions but i can't find the answer i'm looking for:
Is it possible to set a style in XAML that selectively affects controls?
This is working for me. The part that's doing the work is TabControl.ItemContainerStyle. It applies a font size only to the header content.
<TabControl>
<TabControl.ItemContainerStyle>
<Style
TargetType="TabItem"
BasedOn="{StaticResource {x:Type TabItem}}"
>
<Setter Property="HeaderTemplate">
<Setter.Value>
<DataTemplate>
<ContentControl
TextElement.FontSize="20"
Content="{Binding Header, RelativeSource={RelativeSource AncestorType=TabItem}}"
/>
</DataTemplate>
</Setter.Value>
</Setter>
</Style>
</TabControl.ItemContainerStyle>
<TabItem Header="Foo">
<Label Content="Bar" />
</TabItem>
<TabItem Header="Baz">
<Label Content="Bar" />
</TabItem>
</TabControl>
You cannot stop it, it's not the style causing this unwanted trickle-down effect you want rid of; it's just how WPF controls work.
What you will have to do to stop this is write another style for your tab items to intercept the one being inherited from the TabControl.
I suggest writing this style inside your existing TabControl style, inside the Style.Resources tag like so:
<Style x:Key="SideBarTabControl" TargetType="{x:Type TabControl}" BasedOn="{StaticResource {x:Type TabControl}}" >
<Style.Resources>
<Style TargetType="{x:Type TabItem}">
<Setter Property="FontSize" Value="9001"/>
<!-- Any other setters you want for TabItems -->
</Style>
</Style.Resources>
<Setter Property="FontSize" Value="{DynamicResource TitleFontSize}"/>
</Style>
By making a style inside your other style's resources, it will be carried with it, and by not specifying any x:Key for the TabItem style - it will apply it to any TabItem not ordered to have a specific style, becoming the default style for any TabItem you make inside the TabControl now.

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>

How to define all textblock elements the same color

We are using global styles definitions for most of the types. We define then in the app.xaml file. When using TextBlock it is a problem to define a foreground color because it changes all the controls using TextBlock (Button's content color for example).
How can we define a global style which will act only on specific TextBlock usages?
current problematic usage:
<Style TargetType={x:Type TextBlock}>
<Setter Property="Foreground" Value="Red"/>
</Style>
Since I don't think there is a way to differentiate “your” TextBlocks and those that are part of other controls, your options are quite limited.
You could create named Style and add Style="{StaticResource coloredTextBlock}" or Foreground="{StaticResource textBlockColor}" to all TextBlocks. This would be quite tedious and non-DRY.
You could create your own type that inherits from TextBlock and style that. This has some of the disadvantages of the above solution (you have to remember doing that). But it has much less repetition.
This is because ContentPresenter creates a TextBlock for a string content, and since that TextBlock isn't in the visual tree, it will lookup to Application level resource. And if you define a style for TextBlock at Application level, then it will be applied to these TextBlock within ControlControls.
A workaround is to define a DataTemplate for System.String, where we can explicitly use a default TextBlock to display the content. You can place that DataTemplate in the same dictionary you define the TextBlock style so that this DataTemplate will be applied to whatever ContentPresenter effected by your style.
Add this to your Application resources and it should work for you -
<DataTemplate DataType="{x:Type system:String}">
<TextBlock Text="{Binding}">
<TextBlock.Resources>
<Style TargetType="{x:Type TextBlock}"/>
</TextBlock.Resources>
</TextBlock>
</DataTemplate>
Declare a namespace in your xaml, if not referred already -
xmlns:system="clr-namespace:System;assembly=mscorlib"
EDIT : Check this sample where its working..
<Style TargetType="{x:Type TextBlock}">
<Setter Property="Foreground" Value="Red"/>
</Style>
<DataTemplate DataType="{x:Type system:String}">
<TextBlock Text="{Binding}">
<TextBlock.Resources>
<Style TargetType="{x:Type TextBlock}"/>
</TextBlock.Resources>
</TextBlock>
</DataTemplate>
<Style TargetType="{x:Type Button}">
<Setter Property="Foreground" Value="Yellow"/>
</Style>
<Style TargetType="{x:Type Label}">
<Setter Property="Foreground" Value="Blue"/>
</Style>
Just provide a x:key in the style, like:
<Style x:Key="stRedTextBlock" TargetType={x:Type TextBlock}>
<Setter Property="Foreground" Value="Red"/>
</Style>
and mention the key in the TextBlock control style, where ever you require this particular TextBlock style, like:
<TextBlock Name="textBlock1" Style="{StaticResource stRedTextBlock}" />

WPF Replacing AND extending styles

How do I change what WPF's idea of the default style for a control is? And why is this happening in the first place? In the below XAML, I declare a Style for Button, and then further declare a new Style that overrides one of the setters called "HugeBut". I would expect that HugeBut is implicitly BasedOn my new un-named style, but apparently it is not;
<Window.Resources>
<Style TargetType="{x:Type Button}">
<Setter Property="Foreground" Value="Black"/>
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type Button}">
<Border Background="Red">
<ContentPresenter/>
</Border>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
<!-- badness -->
<Style TargetType="{x:Type Button}" x:Key="HugeBut">
<Setter Property="Foreground" Value="Yellow"/>
</Style>
<!-- works, but I do not want to explicitly set the based-on. -->
<Style TargetType="{x:Type Button}" x:Key="HugeBut" BasedOn="{StaticResource {x:Type Button}}">
<Setter Property="Foreground" Value="Yellow"/>
</Style>
</Window.Resources>
<Button Content="Regular" />
<Button Content="huge!" Style="{StaticResource HugeBut}"/>
You would expect two red buttons, one with black text and one with yellow, but Style HugeBut inherits all of the values that I did not specify in my unnamed style from the system default theme for Button (Aero in my case).
What can I do to change this behavior?
It appears that the answer is here:
http://wpfthemereplacer.codeplex.com/
From the site description:
This library allows users to provide their own resource dictionaries
to replace the default theme dictionaries loaded by WPF. This makes it
so you don't have to decorate custom styles with
BasedOn="{StaticResource {x:Type ...}}" when your own custom theme is
being used in your application. It also makes it so if you have custom
controls that just provide enhanced capability and don't need to
replace the the style, you don't need to define a new style or
override the DefaultStyleKey when you create the custom control.
This is exactly what I'm looking for. This will allow me to use Styles as they are meant to be used across an app that has been extensively "re-themed", rather than theme-ing by setting global styles (and then deal with tracking down bits of code that are missing BasedOn, or cannot deal with it at all due to WPF bugs and other constraints)
works, but I do not want to explicitly set the based-on.
Well, the framework does not really care if you don't want to, for all i know, you have to.

Why does x:Key unapply my TabItem Style

I am trying to make a custom style for a TabItem Header. I got it to work by accident.
this fails:
<Style TargetType="{x:Type TabItem}" x:Name="TabHeader3" x:Key="test">
but this works
<Style TargetType="{x:Type TabItem}" x:Name="TabHeader3">
What's going on?
The first Style you have defined is an "explicit" Style, so you must explicitly use it like so:
<TabItem Style="{StaticResource test}" />
The second Style you have defined is an "implicit" Style. So it will be applied to all TabItem controls below it in the visual/logical tree, or to all TabItem controls if it's defined in the application resources.
Your second Style is equivalent to:
<Style TargetType="{x:Type TabItem}" x:Name="TabHeader3" x:Key="{x:Type TabItem}">
So the key is the Type of the object to which it should be applied.
If a TabItem has a Style explicitly defined (like I show above), then any implicit Styles will not be used. Also, if you have two implicit Styles defined, then the closest one wins. So here:
<Window>
<Window.Resources>
<Style TargetType="{x:Type TabItem}">
<Setter Property="Background" Value="Red" />
</Style>
</Window.Resources>
<Grid>
<Grid.Resources>
<Style TargetType="{x:Type TabItem}">
<Setter Property="Background" Value="Blue" />
</Style>
</Grid.Resources>
...
<TabItem ... />
...
</Grid>
</Window>
The Blue Style will take precedence over the Red Style.
Finally, you generally don't need to include x:Name on your Styles.
If you add the style to a resource dictionary without a key then the style gets applied to all TabItems that are within the scope of the resource dictionary by default. If you add a Key to the style then you need to manually set the Style

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