Overriding single property setter from ResourceDictionary - wpf

I have a style defined in a file called MyStyles.xaml:
<Style TargetType="{x:Type igDP:XamDataGrid}">
<Setter Property="FontSize" Value="10" />
<Setter Property="FontFamily" Value="Arial" />
<EventSetter Event="CellUpdating" Handler="grid_CellUpdating"/>
</Style>
In one of my views, I have a XamDataGrid defined:
<igDP:XamDataGrid>
<igDP:XamDataGrid.Resources>
<ResourceDictionary>
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary Source="/MyProject.TheViews;component/Views/MyStyles.xaml"/>
</ResourceDictionary.MergedDictionaries>
<Style TargetType="{x:Type igDP:XamDataGrid}" BasedOn="{StaticResource {x:Type igDP:XamDataGrid}}">
<Setter Property="FontSize" Value="70"/>
</Style>
</ResourceDictionary>
</igDP:XamDataGrid.Resources>
Basically, I want to keep everything that is defined in the style for XamDatagrid in MyStyles.xaml except for the font size, which I want to be set to 70.
I can't seem to get it to work. With the above, the font is set to 70 but I lose the other settings that are defined in MyStyles (such as the event handling and font family).
What am I doing wrong here?

(Extracting an answer from comments above.)
For overriding the style, I would suggest the following:
Define 2 styles in MyStyles.xaml: a named one which contains the style, and the unnamed one (this will be the default style) simply based on the named one
<Style x:Key="XamDataGridDefaultStyle" TargetType="{x:Type igDP:XamDataGrid}">
<Setter Property="FontSize" Value="10" />
<Setter Property="FontFamily" Value="Arial" />
<EventSetter Event="CellUpdating" Handler="grid_CellUpdating"/>
</Style>
<Style TargetType="{x:Type igDP:XamDataGrid}"
BasedOn="{StaticResource XamDataGridDefaultStyle}"/>
This will define the needed default style for all the views.
For the resources of the view where the customization is needed, define the following override:
<Style TargetType="{x:Type igDP:XamDataGrid}"
BasedOn="{StaticResource XamDataGridDefaultStyle}">
<Setter Property="FontSize" Value="70"/>
</Style>
You'll perhaps need to reference MyStyles.xaml as merged dictionary in the resources of the customized view for StaticResource to work.

Related

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>

Setting an Elements.Resource Style using BasedOn within a Resource Dictionary

I have a Resource Dictionary that I am using to define the look-and-feel (style) for my application.
I have just created another Resource Dictionary that contains DataTemplates that I am using on several different screens (and even multiple times within the same screen) to display my business objects.
I would like to change some of the default styles within my DataTemplates so that the controls fit better; however I would like the controls to inherit the same style as the rest of the screen. So, naturally I want to use the BasedOn property for this task.
The problem that I am having is that I'm not sure what to set the BasedOn property to.
For example, in the resource dictionary that contains my styles (called "myStyle.xaml") I have:
<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:primatives="clr-namespace:System.Windows.Controls.Primitives;assembly=PresentationFramework"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
<Style TargetType="{x:Type Label}">
<Setter Property="Foreground" Value="#F5F5F5" />
<Setter Property="FontSize" Value="12"></Setter>
<Setter Property="Width" Value="120"></Setter>
<Setter Property="FontFamily" Value="Arial"></Setter>
</Style>
<Style TargetType="{x:Type TextBox}">
<Setter Property="FontSize" Value="12"></Setter>
<Setter Property="Width" Value="120"></Setter>
<Setter Property="Height" Value="25"></Setter>
<Setter Property="Background" Value="Black"></Setter>
</Style>
<!-- .... and so on .... -->
</ResourceDictionary>
I am using this resource in the following window:
<Window x:Class="SiteSetupWindow4"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:primatives="clr-namespace:System.Windows.Controls.Primitives;assembly=PresentationFramework"
Title="A Screen">
<Window.Resources>
<ResourceDictionary x:Key="defaultStyleX">
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary x:Name="DefaultStyles" Source="Resources/myStyle.xaml" />
<ResourceDictionary x:Name="Templates" Source="Resources/myTemplates.xaml"></ResourceDictionary>
</ResourceDictionary.MergedDictionaries>
</ResourceDictionary>
</Window.Resources>
Now, I have another Resource Dictionary that contains DataTemplates that I am using within my window. It is called "myTemplates". The style is applied to the DataTemplate as expected; however, I would like to overwrite some aspects of the style within the DataTemplate (Like width for example).
This is what I have tired, however I cannot get the BasedOn property to work...
(myTemplate.xaml)
<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
<DataTemplate x:Key="PanelInfo">
<StackPanel>
<StackPanel.Resources>
<Style TargetType="TextBox" BasedOn="{StaticResource {x:Type TextBox}}">
<Setter Property="Width" Value="120" />
</Style>
<Style TargetType="Label">
<Setter Property="Width" Value="180" />
</Style>
<Style TargetType="ComboBox">
<Setter Property="Width" Value="120" />
</Style>
<StackPanel.Resources>
<StackPanel Orientation="Horizontal">
<Label Content="Type:"></Label>
<ComboBox>
<ComboBoxItem Content="{Binding Path=Type}" IsSelected="True"></ComboBoxItem>
</ComboBox>
<!--...and so on -->
</StackPanel>
</StackPanel>
</ResourceDictionary>
This fails....I have also tried using DynamicResource, but this also fails.
I'm not sure how to get around this.
Any advise would be greatly appreciated!
Thanks,
-Frinny
I was having the same problem with an extended Button Style.
The ResourceKey= is what solved it for me.
This worked:
<Style x:Name="ButtonVisibility"
TargetType="{x:Type Button}"
BasedOn="{StaticResource ResourceKey={x:Type Button}}">
The way you have BasedOn for a type is correct. This will work in theory as long as, at run time, the style that you are basing it on is merged into the tree correctly. Make sure you have the "myStyles.xaml" merged in correctly. You can check this by removing your style you tried to modify and make sure it displays correctly from your style in "myStyles.xaml."
If it isn't there are a lot of places you can go wrong, but it always helps to try merging the styles in the file you are working on, then work up the tree to see where it's missing.
This utility will help you look at what is happing in the tree at run time.
http://blois.us/Snoop/

How do I alter the default style of a button without WPF reverting from Aero to Classic?

I've added PresentationFramework.Aero to my App.xaml merged dictionaries, as in...
<Application
x:Class="TestApp.App"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
<Application.Resources>
<ResourceDictionary>
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary
Source="/PresentationFramework.Aero;component/themes/Aero.NormalColor.xaml" />
<ResourceDictionary
Source="pack://application:,,,/WPFToolkit;component/Themes/Aero.NormalColor.xaml" />
<ResourceDictionary
Source="/CommonLibraryWpf;component/ResourceDictionaries/ButtonResourceDictionary.xaml" />
<!-- Note, ButtonResourceDictionary.xaml is defined in an external class library-->
</ResourceDictionary.MergedDictionaries>
</ResourceDictionary>
</Application.Resources>
</Application>
I'm trying to modify the default look of buttons just slightly. I put this style in my ButtonResourceDictionary:
<Style TargetType="Button">
<Setter Property="Padding" Value="3" />
<Setter Property="FontWeight" Value="Bold" />
</Style>
All buttons now have the correct padding and bold text, but they look "Classic", not "Aero". How do I fix this style so my buttons all look Aero but also have these minor changes? I would prefer not to have to set the Style property for every button.
Update
I should have mentioned this in the first place, but if I try to use BasedOn, as shown below, I get a StackOverflowException:
<Style BasedOn="{StaticResource {x:Type Button}}" TargetType="{x:Type Button}">
<Setter Property="Padding" Value="3" />
<Setter Property="FontWeight" Value="Bold" />
</Style>
This would normally work, but not with the Aero dictionaries merged in. If I comment those dictionaries out, the exception disappears.
Update 2
If I add an x:Key attribute and manually set the style, it works properly (Aero style with padding and bold), but as I said, I'd prefer that the style is automatically applied globally to all buttons.
Update 3
I just discovered a new wrinkle. In my app, ButtonResourceDictionary.xaml is placed in a class library (i.e., in an external project). If I move this file to a local folder, everything works fine. So, the problem seems to be a bad interaction caused by referencing various external resource dictionaries. I'm correcting my App.xaml code snippet (above) to reflect that ButtonResourceDictionary is actually defined externally.
I hope you've found a solution in the meantime. For everyone else, here is one workaround, and here is another. I am not sure whether this will help for your specific case though (especially the fact that you reference an embedded resource dictionary).
UPDATE
Here's a solution I came up with:
<Style TargetType="TextBox" BasedOn="{Common:StaticApplicationResource {x:Type TextBox}}">
<Setter Property="Height" Value="21"/>
</Style>
Where StaticApplicationResource is a custom MarkupExtension I wrote that simply calls TryFindResource:
[MarkupExtensionReturnType(typeof(object))]
public class StaticApplicationResource : MarkupExtension
{
public StaticApplicationResource(object pResourceKey)
{
mResourceKey = pResourceKey;
}
private object _ResourceKey;
[ConstructorArgument("pResourceKey")]
public object mResourceKey
{
get { return _ResourceKey; }
set { _ResourceKey = value; }
}
public override object ProvideValue(IServiceProvider serviceProvider)
{
if (mResourceKey == null)
return null;
object o = Application.Current.TryFindResource(mResourceKey);
return o;
}
}
This way I don't have to reference my resource dictionaries outside of my App.xaml file , which is the way I like it :). You can also put more complicated logic in there too, allowing you to resolve the BasedOn style any way you like. Here is an excellent article showing you how to load resource dictionaries (and those that the framework resolves automatically) from code.
Based on your updates, you could do this (admittedly it is hideously ugly):
<Style x:Key="_buttonStyleBase"
BasedOn="{StaticResource {x:Type Button}}"
TargetType="{x:Type Button}">
<Setter Property="Padding" Value="3" />
<Setter Property="FontWeight" Value="Bold" />
</Style>
<Style TargetType="{x:Type Button}"
BasedOn="{StaticResource _buttonStyleBase}" />
Use the BasedOn attribute to inherit the properties from the Aero Style. This should solve your problem.
<Style
BasedOn="{StaticResource {x:Type Button}}"
TargetType="{x:Type Button}">
<Setter Property="Padding" Value="3" />
<Setter Property="FontWeight" Value="Bold" />
</Style>

WPF datagrid styling

I want to style a WPF datagrid and it seems to be really easy . As far as I understand I have to have code such as the following:
<Style x:Key="DataGridColumnHeaderStyle" TargetType="{x:Type Custom:DataGridColumnHeader}" >
<Setter Property="Background" Value="#88800080" />
<Setter Property="Foreground" Value="White" />
</Style>
But my question is ..where do I place this code and how do I let the datagrid know to use the style above ?
Regards,
S
Put it in the resource of the xaml (local or global). The easiest is to put it in the local resource of the current xaml file:
<Page Name="SomeName"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
<Page.Resources>
<Style x:Key="DataGridColumnHeaderStyle" TargetType="{x:Type Custom:DataGridColumnHeader}" >
<Setter Property="Background" Value="#88800080" />
<Setter Property="Foreground" Value="White" />
</Style>
</Page.Resources>
<!-- The rest of the xaml -->
</Page>
The best place to put styles is in a resource dictionary, referenced in App.xaml.
Resource dictionary ("StyleResources.xaml" in this example):
<ResourceDictionary
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
<Style x:Key="TextBlockRightAlign" TargetType="TextBlock">
<Setter Property="HorizontalAlignment" Value="Right" />
</Style>
<Style x:Key="TextBlockTitle" TargetType="TextBlock">
<Setter Property="FontSize" Value="20" />
<Setter Property="FontWeight" Value="Bold" />
</Style>
</ResourceDictionary>
Referencing the style dictionary in App.xaml:
<Application.Resources>
<ResourceDictionary>
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary Source="StyleResources.xaml"/>
</ResourceDictionary.MergedDictionaries>
<ValueConverters:PriceConverter x:Key="PriceConverter"/>
</ResourceDictionary>
</Application.Resources>
Using the definition in a datagrid (column formatting here, but should work for headers as well):
<data:DataGridTextColumn Header="Charge" Width="100"
Binding="{Binding Charge, Mode=TwoWay, Converter={StaticResource PriceConverter}}"
ElementStyle="{StaticResource TextBlockRightAlign}" />
Note that the element inside the cell is a TextBlock, so you can use a style with a target type of TextBlock.
As for the "Type DataGridColumnHeader was not found": you need a second xml namespace entry since the DataGridColumnHeader is in the System.Windows.Controls.Primitives namespace. You need something like
xmlns:dg="clr-namespace:Microsoft.Windows.Controls.Primitives;assembly=WPFToolkit"
and then reference the new namespace in your style, e.g.
<Style x:Key="DataGridColumnHeaderStyle" TargetType="{x:Type dg:DataGridColumnHeader}" >
Styles usually go:
<UserControl.Resources>
<Style x:Key="DataGridColumnHeaderStyle" TargetType="{x:Type Custom:DataGridColumnHeader}" >
<Setter Property="Background" Value="#88800080" />
<Setter Property="Foreground" Value="White" />
</Style>
</UserControl.Resources>
Use the appropriate container if this isn't within a UserControl you may use "Window" or whatever container you're in.
Also you need to reference it in your datagrid with:
<Custom:DataGrid ColumnHeaderStyle="{StaticResource DataGridColumnHeaderStyle}"/>

Can you define multiple TargetTypes for one XAML style?

In HTML/CSS you can define a style which can be applied to many types of elements, e.g.:
.highlight {
color:red;
}
can be applied to both P and DIV, e.g.:
<p class="highlight">this will be highlighted</p>
<div class="highlight">this will also be highlighted</div>
but in XAML you seem to have to define the TargetType for styles, otherwise you get an error:
<Style x:Key="formRowLabel" TargetType="TextBlock">
is there a way to allow a XAML style to be applied to multiple elements or even to leave it open as in CSS?
The setters in WPF styles are checked during compile time; CSS styles are applied dynamically.
You have to specify a type so that WPF can resolve the properties in the setters to the dependency properties of that type.
You can set the target type to base classes that contain the properties you want and then apply that style to derived classes. For example, you could create a style for Control objects and then apply it to multiple types of controls (Button, TextBox, CheckBox, etc)
<Style x:Key="Highlight" TargetType="{x:Type Control}">
<Setter Property="Foreground" Value="Red"/>
</Style>
...
<Button Style="{StaticResource Highlight}" Content="Test"/>
<TextBox Style="{StaticResource Highlight}" Text="Test"/>
<CheckBox Style="{StaticResource Highlight}" Content="Test"/>
<!-- Header text style -->
<Style x:Key="headerTextStyle">
<Setter Property="Label.VerticalAlignment" Value="Center"></Setter>
<Setter Property="Label.FontFamily" Value="Trebuchet MS"></Setter>
<Setter Property="Label.FontWeight" Value="Bold"></Setter>
<Setter Property="Label.FontSize" Value="18"></Setter>
<Setter Property="Label.Foreground" Value="#0066cc"></Setter>
</Style>
<!-- Label style -->
<Style x:Key="labelStyle" TargetType="{x:Type Label}">
<Setter Property="VerticalAlignment" Value="Top" />
<Setter Property="HorizontalAlignment" Value="Left" />
<Setter Property="FontWeight" Value="Bold" />
<Setter Property="Margin" Value="0,0,0,5" />
</Style>
I think both of these methods of declaring a style might answer your question.
In the first one, there is no TargetType specified, but the property names are prefixed with 'Label'. In the second one, the style is created for Label objects.
Another method to do it is:
<UserControl.Resources>
<Style x:Key="commonStyle" TargetType="Control">
<Setter Property="FontSize" Value="24"/>
</Style>
<Style BasedOn="{StaticResource commonStyle}" TargetType="ListBox"/>
<Style BasedOn="{StaticResource commonStyle}" TargetType="ComboBox"/>
</UserControl.Resources>
I wanted to apply a style to a Textblock and a TextBox but the selected answer didn't work for me because Textblock doesn't inherit from Control, in my case I wanted to affect the Visibility property, so I used FrameworkElement
<Style x:Key="ShowIfRequiredStyle" TargetType="{x:Type FrameworkElement}">
<Setter Property="Visibility" Value="Collapsed"/>
<Style.Triggers>
<DataTrigger Binding="{Binding ShowIfRequiredStyle, UpdateSourceTrigger=PropertyChanged}" Value="true">
<Setter Property="Visibility" Value="Visible"/>
</DataTrigger>
</Style.Triggers>
</Style>
<TextBlock Style="{StaticResource ResourceKey=ShowIfRequiredStyle}"/>
<TextBox Style="{StaticResource ResourceKey=ShowIfRequiredStyle}"/>
This works for the Visibility property because both items inherit from Frameworkelement and the property is defined there. Of course this will not work for properties defined only in Control, you can search the hierarchy tree and try to find a base class, anyway I thought this could help someone since this is a top search result and the selected answer is a little incomplete.
There is an alternative answer to the question. You CAN leave the TargetType parameter off the style altogether which will allow it to apply to various different controls, but only if you prefix the property name with "Control."
<Style x:Key="Highlight">
<Setter Property="Control.Foreground" Value="Red"/>
</Style>
Obviously, this only works for properties of the base control class. If you tried to set ItemsSource say, it would fail because there is no Control.ItemsSource
I got this working
<Style x:Key="HeaderStyleThin" TargetType="{x:Type Border}">
<Setter Property="Background" Value="Black" />
<Style.Resources>
<Style TargetType="{x:Type TextBlock}">
<Setter Property="Background=" Value="Red" />
</Style>
</Style.Resources>
</Style>

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