Strange Style Behaviour in wpf? - wpf

Ok, I was programming an app that loaded merged dictionaries on runtime to change appearance and behaviour when I got stuck : some of the controls on my forms just weren't reacting to the styles I thought they had to react to.
I have tried to simplify the problem as much as I could and came up with something so simple that I'm afraid I am overlooking the bleeding obvious, but anyway here it goes :
<Window x:Class="Example.Window1"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="Window1" Height="100" Width="50">
<Window.Resources>
<ResourceDictionary>
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary>
<Style TargetType="{x:Type TextBox}">
<Setter Property="Background" Value="Green"></Setter>
</Style>
</ResourceDictionary>
</ResourceDictionary.MergedDictionaries>
</ResourceDictionary>
</Window.Resources>
<StackPanel>
<TextBox Text="1" Name="box1"/>
<TextBox Text="2" Name="box2"/>
<TextBox Text="3" Name="box3"/>
</StackPanel>
</Window>
The question is : why is the first textbox not green?
==> that is, the designer shows it in green, but when running the app, it is no longer...
I know the solotion to this particular problem is to remove the merged dicitonary tags, but I need to know how to solve this using merged dictionaries.
Thanks!

MergedDictionaries have always been quirky, you can set any resources you want in them, but they only process outside resource dictionary references at runtime.
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary Source="StylesDictionary.xaml"/>
</ResourceDictionary.MergedDictionaries>
The only requirement is that the resources be set in an other dictionary.

Try this...
<Style TargetType="{x:Type TextBox}">

I'm not sure if this will work, but when I was having styling problems, I fixed them by using
TargetType="{x:Type TextBox}"

Related

How should application wide resources be organized?

Here is the scenario:
I have been using VS 2010 to write quite a large WPF project using MEF. There are multiple projects within this solution and I have one ResourceDictionary for all of my styles.
The AppStyles.xaml ResourceDictionary is located in my startup project, it contains all of my styles for the project. And within my App.xaml I have the following:
<Application x:Class="Dionysus.Shell.App"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
DispatcherUnhandledException="UnhandledException" ShutdownMode="OnMainWindowClose">
<Application.Resources>
<ResourceDictionary>
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary Source="AppStyles.xaml"/>
</ResourceDictionary>
</Application.Resources>
Now, this all works perfectly in design mode of VS 2010 and when I am debugging, the correct styles are being applied to all of my controls. But I recently switched to VS 2012, and the designer is no longer working! When I debug it works perfectly but whenever I use one of my styles as follows:
<Button Name="btnForward" Height="23" Margin="10,0" Style="{StaticResource DionysusButton}" Grid.Row="2" Grid.Column="0"/>
I get the following error in the VS 2012 designer:
The resource "DionysusButton" could not be resolved.
I am clueless as to why this is happening, I have renamed my Style, and even the ResourceDictionary to no avail.
Is there a different way I should be doing this in VS 2012 or is this a problem with VS 2012?
I have found a lot of posts that say that changing the x:Name property of my AppStyles.xaml ResourceDictionary to x:Key will resolve this problem but I cannot do that as it is not a valid option for a ResourceDictionary.
Thanx in advance
-- UPDATE
I am using Marc's answer and all seems to be going well except for default styles. I have the following style:
<Style TargetType="DataGrid" x:Name="DataGridStyle"/>
And this is my main ResourceDictionary:
<ResourceDictionary x:Name="Main"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary Source="Styles/AppStyling.xaml" />
</ResourceDictionary.MergedDictionaries>
<Style TargetType="DataGrid" BasedOn="{StaticResource DataGridStyle}"/>
When I do not add the Style tag in my main ResourceDictionary it works fine, but the style is not being applied to all items obviously. When I do add it, i get the following exception:
Provide value on 'System.Windows.Markup.StaticResourceHolder' threw an exception
Ideas?
Are you trying to use the styles which are located in your app.xaml in your modules which you export into the shell using PRISM? The modules should not have a reference to your application/shell project (the startup project)? Then they maybe just don't 'know' the project, which contains the styles? Though the question is why it works in VS2010 then... Please let me know, if I misunderstood your MEF scenario, I'll adapt my answer then.
Resources and Prism is abit tricky, and I am a fan of the following approach, which I have posted before, but it might help in your case too. It is much more appropriate for a PRISM solution than placing your resources inside app.xaml:
I usually create a seperate styling project, which I reference from the projects, which I want to style. The styling project has a fixed structure like this:
For every control, I create a styling ResourceDictionary. For example for my buttons:
<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
<Style x:Key="PrimaryButtonStyle" TargetType="Button">
</Style>
<Style x:Key="ToolbarButton" TargetType="Button">
<Setter Property="BorderThickness" Value="0" />
<Setter Property="Margin" Value="3"/>
<Setter Property="Background" Value="Transparent"></Setter>
</Style>
</ResourceDictionary>
In one main ResourceDictionary, I merge all the other dictionaries, in this case in the file IncaDesign.xaml, which you can see in the picture above:
<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:controls="clr-namespace:Commons.Controls;assembly=Commons">
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary Source="Converter/Converter.xaml" />
<ResourceDictionary Source="Styles/Button.xaml" />
<ResourceDictionary Source="BitmapGraphics/Icons.xaml" />
</ResourceDictionary.MergedDictionaries>
<!-- Default Styles -->
<Style TargetType="Button" BasedOn="{StaticResource PrimaryButtonStyle}"></Style>
</ResourceDictionary>
Notice how I defined the default styles, which are applied automatically, unless you specify otherwise. In every window or control, that you want to style, you only need to reference this one ResourceDictionary. Note the definition of the source, which is a reference to the assembly (/Commons.Styling;component...)
<UserControl.Resources>
<ResourceDictionary>
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary Source="/Commons.Styling;component/IncaDesign.xaml" />
</ResourceDictionary.MergedDictionaries>
<!-- Here you can added resources which belong to the UserControl only -->
<!-- For example: -->
<DataTemplate x:Kex="UcTemplate" />
</ResourceDictionary>
</UserControl.Resources>
Default styles will be set automatically now, and if you want to access a resource explicitly, you can do this, using StaticResource.
<Viewbox Height="16" Width="16" Margin="0,0,10,0">
<ContentControl Content="{StaticResource FileIcon32}" />
</Viewbox>
This is very nice solution in my opinion, which works for very complex solutions, including modular solutions, for example built with PRISM.

DynamicResource Cannot be resolved

I have been trying to learn about resources and styles, I want to create a chromeless window.
I have an example that acheives what I want via the following simple extracts of xaml.
I have a Resource set in Themes/Generic.xaml
<Style x:Key="BorderlessWindowStyle" TargetType="{x:Type Window}">
<Setter Property="AllowsTransparency" Value="true" />
<Setter Property="WindowStyle" Value="None" />
<Setter Property="ResizeMode" Value="CanResizeWithGrip" />
<Setter Property="Background" Value="Transparent" />
</Style>
I have a main window:
<Window x:Class="Project1.Shell"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:Project1"
x:Name="Window"
Title="Shell" Height="576" Width="1024" Style="{DynamicResource BorderlessWindowStyle}">
<Grid></Grid>
But the style is not being applied and VS designer states it cannot resolve the resource.
The example I have been looking at does things this way and I cannot discover the difference between what I have seen done and what I am trying to do.
I thought that Genric.xaml was a 'special' resource dictionary that should be discoverable by my Window control - and I am guessing this assumption is my error.
What do I need to do to make this work? (Now I understand I can set these properties in the Window xaml directly, and I have done so and get the effect I want. BUT I really want to undersatnd using the Generic.xaml resource dictionary way as I have presented here)
best regards
John.
Themes/generic.xaml file is automatically used to find default styles for Custom Controls. In your case you have an ordinary Window with custom style. You cannot define this style in Window.Resources section, because the style should be defined at a higher level. The only higher level of Window is App.xaml, because the Window is in fact its child. That's why the solution for your question is to place the style into App.Resources section.
Thought I would add the following example in case it helps some others out. To add a resource dictionary to your app.xaml file you can add the following xaml code to the app.xaml file.
<Application x:Class="ProjectX.App"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:ProjectX"
StartupUri="MainWindow.xaml">
<Application.Resources>
<ResourceDictionary>
<ResourceDictionary.MergedDictionaries>
<!-- Use the Black skin by default -->
<ResourceDictionary Source="Resources\ResourceFile.xaml"/>
</ResourceDictionary.MergedDictionaries>
</ResourceDictionary>
</Application.Resources>
Where 'Resources' coudl be a folder in your project that contains the Resource Dictionary file (ResourceFile.xaml).
The you can add code to your resource dictionary like such:
<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="clr-namespace:ProjectX.Resources">
<!-- The Background Brush is used as the background for the Main Window -->
<SolidColorBrush x:Key="MainBackgroundBrush" Color="#FF202020" />
</ResourceDictionary>
And then finally, dynamically bind to your resource dictionary doing something like:
<Window
x:Class="ProjectX.MainWindow"
Title="Family.Show" Height="728" Width="960"
Background="{DynamicResource MainBackgroundBrush}"
ResizeMode="CanResizeWithGrip">
</Window>

Apply themes to wpf and use styles

I am trying to apply a theme to a bunch of wpf projects. There is one assembly containing the generic.xaml and different applications. As far as i understand i can't use the ThemeInfo attribute with ResourceDictionaryLocation.ExternalLocation because the name have to be the same as my program but I have more than one program...
So I search and found that I only have to include the dictionary as MergedDictionary in the app.xaml
<Application.Resources>
<ResourceDictionary>
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary Source="/ClassLibrary1;component/Themes/generic.xaml" />
</ResourceDictionary.MergedDictionaries>
</ResourceDictionary>
</Application.Resources>
This basically works. But if I use a style for the controls it will not apply the generic.xaml style anymore:
generic.xaml in ClassLibrary1.dll
<ResourceDictionary x:Class="ClassLibrary1.Themes.generic"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
<Style TargetType="{x:Type Button}">
<Setter Property="Background"
Value="Black" />
</Style>
Window in program
<Window x:Class="Theming.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="MainWindow" Height="350" Width="525">
<Window.Resources>
<Style TargetType="Button"
x:Key="ButtonGreenTextStyle">
<Setter Property="Foreground"
Value="Green" />
</Style>
</Window.Resources>
<Grid>
<Button Style="{DynamicResource ButtonGreenTextStyle}" Content="Test" />
</Grid>
</Window>
What I have to do, that WPF will understand the style in my generic.xaml as basestyle for all buttons (I know I will also have to write a ControlTemplate; the above code is just for simplicity)
Two things I would try
Create a generic ButtonBase style/template to set the look of all
buttons
Try using a BasedOn attribute on the ButtonGreeTextStyle,
basing it on an existing style.
I found another solution. You have to write styles based on a custom markup:
This will apply the current theme style. The code for this MarkupExtension can be found here:
How do I alter the default style of a button without WPF reverting from Aero to Classic?

Loading WPF Style from Resource File

I am trying to load WPF Style from other file actually from WPF Custom Control Library
but i am failing to load here is my solution.
The solution contains two projects
WpfTestControls of Type WPF Custom Control Library
WpfTestApp of type WPF Application Library which has reference to WpfTestControls
MainWindow.xaml from WPF Application Library
<Window.Resources>
<Style x:Key="TempStyle" TargetType="{x:Type TextBox}">
<Setter Property="BorderBrush" Value="Green"/>
</Style>
</Window.Resources>
<Grid>
<TextBox Height="50px" Width="100px" Style="{DynamicResource TempStyle}"/>
</Grid>
Generic.xaml from WPF Custom Control Library
<ResourceDictionary
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary Source="/WpfTestControls;component/TextBoxStyle.xaml"/>
</ResourceDictionary.MergedDictionaries>
TextBoxStyle.xaml from WPF Custom Control Library
<ResourceDictionary
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
<Style x:Key="TempStyle" TargetType="{x:Type TextBox}">
<Setter Property="BorderBrush" Value="Green"/>
</Style>
My AssemblyInfo.cs file contains the following
[assembly: ThemeInfo(
ResourceDictionaryLocation.None, //where theme specific resource dictionaries are located
//(used if a resource is not found in the page,
// or application resource dictionaries)
ResourceDictionaryLocation.SourceAssembly //where the generic resource dictionary is located
//(used if a resource is not found in the page,
// app, or any theme specific resource dictionaries))]
But still i am failing to load the Style.
If i am using the not using the Generic.xaml everything work fine for example the following code works as expected
<Window x:Class="WpfTestApp.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="MainWindow" Height="350" Width="525">
<Window.Resources>
<Style x:Key="TempStyle" TargetType="{x:Type TextBox}">
<Setter Property="BorderBrush" Value="Green"/>
</Style>
</Window.Resources>
<Grid>
<TextBox Height="50px" Width="100px" Style="{StaticResource TempStyle}"/>
</Grid>
What am i doing wrong ?
Thanks in advance
Please answer few things for me...
Is "WPF Custom Control Library" assembly same as "WpfTestControls" assembly?
If not, then does "WPF Custom Control Library" have a reference to the "WpfTestControls" assembly?
Does your WpfTestApp have a reference to both "WPF Custom Control Library" and "WpfTestControls" assemblies?
If you add that reference(s), the resources should load correctly.
My Steps...
Add a "WPF Custom Control Library" say "ThemesLibray"
In this add two resource dictionaries under "Themes" folder
TextBoxStyle.xaml
<ResourceDictionary
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
<Style x:Key="GreenTextBoxStyle" TargetType="{x:Type TextBox}">
<Setter Property="Background" Value="Green"/>
</Style>
</ResourceDictionary>
Generic.xaml
<ResourceDictionary
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary Source="TextBoxStyle.xaml"/>
</ResourceDictionary.MergedDictionaries>
</ResourceDictionary>
I have main starup project "MyWPFTestApp" that has assembly reference to ThemesLibray. In that the window has ThemesLibrary resources merged this way....
<Window x:Class="MyWPFTestApp.Window7"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="Window7" Height="300" Width="300">
<Window.Resources>
<ResourceDictionary>
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary
Source="/ThemseLibrary;component/Themes/Generic.xaml"/>
</ResourceDictionary.MergedDictionaries>
</ResourceDictionary>
</Window.Resources>
<Grid>
<TextBox Style="{StaticResource GreenTextBoxStyle}"/>
</Grid>
</Window>
When I launch MyWPFTestApp, I see the Window with green TextBox.
Main thing is : Make sure you have Build Action of your Resource Dictionary set to Resource.

DataTemplates in resource dictionaries don't inherit from app.xaml styles?

I added custom named styles to the app.xaml.
I created an external resource dictionary (which I attach in the merged dictionaries of the app.xaml) and when I try to use one of the above named styles in the rcource dictionary, it says that there is no such style.
Also the default styles (i.e. unnamed styles that apply for the entire application) don't apply on the template elements.
Note: The Build Action of the templates is 'Page'.
Here is an example of how my code is written:
<Application x:Class="Application"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
ShutdownMode="OnExplicitShutdown">
<Application.Resources>
<ResourceDictionary>
<Style
x:Key="StackPanelStyle"
TargetType="StackPanel"
BasedOn="{StaticResource {x:Type StackPanel}}">
<Setter Property="Margin" Value="5"/>
<Setter Property="Orientation" Value="Horizontal" />
<Setter Property="Height" Value="40"/>
</Style>
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary Source="/Templates/DataTemplate1.xaml"/>
<ResourceDictionary Source="/Templates/DataTemplate2.xaml"/>
<ResourceDictionary Source="/Templates/DataTemplate3.xaml"/>
</ResourceDictionary.MergedDictionaries>
</ResourceDictionary>
</Application.Resources>
</Application>
This an example of the data template:
<DataTemplate DataType="{x:Type Entity}" x:Key="NameDataTemplate">
<Expander>
<StackPanel>
<--The following line produces: StackPanelStyle was not found.-->
<StackPanel Style="{StaticResource StackPanelStyle}">
<Label Content="Name:"/>
<TextBox Text="{Binding Name}"/>
</StackPanel>
</StackPanel>
</Expander>
</DataTemplate>
Any ideas?
Do I have to merge the dictionaries in a different way?
The code won't work well because the DataTemplate in the resource dictionary doesn't know which one is using it, it just been used. Like Hollywood mode. They compiled separately.
To make this work, you can put your style which in app.xaml in the same resource dictionary of the DataTemplate or if you don't like this coupling, you can put it in a different resource dictionary, and merge it into the DataTemplate's resource dictionary.
The Build Action for your App.xaml should be ApplicationDefinition, and the build action for your Resource Dictionary files should be Page. I'm guessing you have both of those correct because they are default (and I see that you mentioned about Page already).
I can't think of any other problem with your situation. As long as your static resources are defined in the correct order, which they appear to be, it should be able to find them when you run your application.
Edit
Debugging idea: Create a fresh resource dictionary called "TestDictionary.xaml" with a simple button style. Make sure this dictionary is in the same folder as your other dictionaries (DataTemplate1.xaml, etc.). Put a link to only TestDictionary in MergedDictionaries (comment out the others). Put a button on your startup window and apply the style. See if just that works. If it fails, you know you have an issue with your merge. If it succeeds, something about your DataTemplate might be the problem.

Resources