I'm scratching my head as to why the following two result in very different behaviour:
<Application x:Class="MN.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="Theme.xaml" />
<ResourceDictionary>
</ResourceDictionary>
</ResourceDictionary.MergedDictionaries>
<BitmapImage x:Key="PlaceholderImage" UriSource="/MN;component/Lib/PlaceholderImage.png"/>
</ResourceDictionary>
</Application.Resources>
</Application>
The above works in that it loads my Theme.xaml ResourceDictionary, and I seem to be able to access the PlaceholderImage BitmapImage with no issue.
However:
<Application x:Class="MN.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="Theme.xaml" />
<ResourceDictionary>
<BitmapImage x:Key="PlaceholderImage" UriSource="/MN;component/Lib/PlaceholderImage.png"/>
</ResourceDictionary>
</ResourceDictionary.MergedDictionaries>
</ResourceDictionary>
</Application.Resources>
</Application>
In this snippet I moved the BitmapImage into the inline ResourceDictionary within MergedDictionaries. Now when I try to run the application I get the following exception:
System.Windows.Markup.XamlParseException: ''Initialization of 'System.Windows.Media.Imaging.BitmapImage' threw an exception.' Line number '11' and line position '44'.'
Looking up the exception it seems like this is generally thrown when the image file could not be resolved, but I'm not sure why that would happen, and I feel like there is some key mechanism that I'm failing to understand here.
I'm looking for insights as to why it doesn't work, how one might typically add a BitmapImage to a merged dictionary.
Related
I'm having trouble referencing a xaml resource dictionary file, leading to a runtime error saying 'resource x can't be found' when referring to a ResourceDictionary inside of . But using the Window.Resources node instead works.
working code:
<Window.Resources>
<ResourceDictionary Source="Resources\Template_1.xaml">
</ResourceDictionary>
</Window.Resources>
my malfunctioning code:
<Application.Resources>
<ResourceDictionary>
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary Source="Resources\Template_1.xaml"/>
</ResourceDictionary.MergedDictionaries>
</ResourceDictionary>
</Application.Resources>
My problem is I need the dictionary in application scope.
I'm accessing it as StaticResource and the build action of Template_1 is set as 'Page'
Any suggestions?
Edit:
this is the structure of Template_1.xaml
<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:self="clr-namespace:Application_1"
>
<ControlTemplate x:Key="dict_TabContent" x:Shared="true" >
<DockPanel>
...
</DockPanel>
</ControlTemplate>
</ResourceDictionary>
I have a Styles.xaml that groups many ResourceDictionarys inside a MergedDictionary.
I imported Styles.xaml in my UserControl.Resources
<UserControl.Resources>
<ResourceDictionary Source="Dictionaries\Styles.xaml" />
</UserControl.Resources>
but when I try to add a converter
<UserControl.Resources>
<ResourceDictionary>
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary Source="Dictionaries\Styles.xaml" /> <--! Exception -->
</ResourceDictionary.MergedDictionaries>
<BooleanToVisibilityConverter x:Key="BooleanToVisibilityConverter"/>
</ResourceDictionary>
</UserControl.Resources>
it raises
ArgumentNullException: Value cannot be null.
Parameter name: item
Wrapping the converter inside another MergedDictionary has no effect.
How can I solve this?
Thank you all!
SOLVED
I eventually figured it out: the Exception was raised inside one the .xaml files, but Visual Studio does not provide enough info to locate the faulty line.
Following code does work.
<UserControl.Resources>
<ResourceDictionary>
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary Source="Dictionaries\Styles.xaml" />
</ResourceDictionary.MergedDictionaries>
<BooleanToVisibilityConverter x:Key="BooleanToVisibilityConverter"/>
</ResourceDictionary>
</UserControl.Resources>
Try this
<UserControl.Resources>
<ResourceDictionary>
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary Source="pack://application:,,,/PROJECTNAMESPACE (TestProject.Something);component/Dictionaries/Styles.xaml" />
</ResourceDictionary.MergedDictionaries>
<BooleanToVisibilityConverter x:Key="BooleanToVisibilityConverter"/>
</ResourceDictionary>
</UserControl.Resources>
I'm using Telerik's RadControls for WPF with implicit styling. The following style is defined in Themes/Windows8/Telerik.Windows.Controls.RibbonView.xaml:
<Style TargetType="telerikRibbonView:RadRibbonView" x:Key="RadRibbonViewStyle">
...
</Style>
My own styles and the Telerik default ones get merged like this in the assembly Lib.Windows.Controls in the folder Themes:
<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary Source="Windows8/Telerik.Windows.Controls.RibbonView.xaml" />
<ResourceDictionary Source="MyTheme/TelerikCustomizations.xaml" />
<ResourceDictionary>
<!-- avoid optimization -->
<Style TargetType="{x:Type Rectangle}" />
</ResourceDictionary>
</ResourceDictionary.MergedDictionaries>
</ResourceDictionary>
And in TelerikCustomizations.xaml I define the following (empty, for testing purposes) style:
<Style x:Key="MyThemeRadRibbonViewStyle" TargetType="{x:Type telerik:RadRibbonView}" BasedOn="{StaticResource ResourceKey=RadRibbonViewStyle}" />
Which results in the following exception at runtime:
'Provide value on 'System.Windows.Markup.StaticResourceHolder' threw an exception.' Line number '4' and line position '42'.
{"Cannot find resource named 'RadRibbonViewStyle'. Resource names are case sensitive."}
Which led me to the following debugging statements in MyView.xaml.cs:
public ShellView()
{
var baseStyle = FindResource("RadRibbonViewStyle");
var inherited = FindResource("MyThemeRadRibbonViewStyle");
InitializeComponent();
}
Now the thing is: The exception is thrown on the second FindResource call. With the exact same message. However the RadRibbonViewStyle is clearly found in the first line of the constructor.
If it matters, the merged dictionary is actually merged in App.xaml a second time.
I'm sure I'm missing something obvious, but I can't figure out what.
App.xaml
<Application x:Class="TestClient.App"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
StartupUri="Views/ShellView.xaml">
<Application.Resources>
<ResourceDictionary>
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary Source="pack://application:,,,/Lib.Windows.Controls;component/Themes/MyTheme.xaml" />
<ResourceDictionary>
<!-- added to avoid optimization -->
<Style TargetType="{x:Type Rectangle}" />
</ResourceDictionary>
</ResourceDictionary.MergedDictionaries>
</ResourceDictionary>
</Application.Resources>
</Application>
App.xaml.cs does not overwrite the constructor. In fact it does not do anything.
Update
If I merge the Telerik dictionaries in TelerikCustomizations.xaml instead of merging them in yet another dictionary (MyTheme.xaml), the exception disappears.
However, I'd still like to know why this happens.
You need to merge in the Windows8/Telerik.Windows.Controls.RibbonView.xaml in your MyTheme/TelerikCustomizations.xaml
<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary Source="Windows8/Telerik.Windows.Controls.RibbonView.xaml" />
<ResourceDictionary>
<Style x:Key="MyThemeRadRibbonViewStyle" TargetType="{x:Type telerik:RadRibbonView}" BasedOn="{StaticResource ResourceKey=RadRibbonViewStyle}" />
</ResourceDictionary>
</ResourceDictionary.MergedDictionaries>
</ResourceDictionary>
And now you can use/merge this dictionary wherever you want.
You need to do this because StaticResource is not working between "sister" MergedDictionaries so you cannot reference a resource which was merged on the same level because the StaticResource looks only backwards to the direct parents:
From MSDN:
XAML resource references within a particular resource dictionary must
reference a resource that has already been defined with a key, and
that resource must appear lexically before the resource reference.
Forward references cannot be resolved by a XAML resource reference
But when using MergedDictionaries:
In the resource-lookup sequence, a MergedDictionaries dictionary is
checked only after a check of all the keyed resources of the
ResourceDictionary that declared MergedDictionaries.
I'm developing a WPF control library, and I need to reference a resource dictionary defined in the same assembly.
I managed to get it working with a separate-assembly reference.
<UserControl.Resources>
<ResourceDictionary>
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary
Source="pack://application:,,,/MyLocalAssembly;component/Foo.xaml"/>
</ResourceDictionary.MergedDictionaries>
</ResourceDictionary>
</UserControl.Resources>
While with a same-assembly reference it doesn't work, and raises an exception ("Cannot locate resource 'Foo.xaml'.") at load time. Note that in the designer everything works fine, no matter which method I use.
<UserControl.Resources>
<ResourceDictionary>
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary
Source="pack://application:,,,/Foo.xaml"/>
</ResourceDictionary.MergedDictionaries>
</ResourceDictionary>
</UserControl.Resources>
Don't use absolute path for the resource dictionary. Simply use relative path reference.
For example,
<UserControl.Resources>
<ResourceDictionary>
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary
Source="folder/Foo.xaml"/>
</ResourceDictionary.MergedDictionaries>
</ResourceDictionary>
</UserControl.Resources>
in order to clean up my code, I'm trying to split my app.xaml into seperate resource dictionaries. This works at runtime, but not at design time:
snipped in app.xaml
<Application.Resources>
<ResourceDictionary>
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary Source="/;component/Theme/Colors.xaml" />
<ResourceDictionary Source="/;component/Theme/Styles.xaml" />
</ResourceDictionary.MergedDictionaries>
</ResourceDictionary>
</Application.Resources>
Colors.xaml
<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
<SolidColorBrush x:Key="backgroundBrush" Color="Gold"/>
</ResourceDictionary>
Styles.xaml
<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
<Style TargetType="StatusBar">
<Setter Property="Background" Value="{StaticResource backgroundBrush}" />
</Style>
</ResourceDictionary>
Snipped of MainWindow.xaml
<Window x:Class="test.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="test" Width="800" Height="600" >
<StatusBar Name="statusBar" DockPanel.Dock="Bottom">
<StatusBarItem Content="{Binding statusMessage}" />
</StatusBar>
DesignView gives the error:
Error 8 '{DependencyProperty.UnsetValue}' is not a valid value for property 'Background'. C:\Daten\DotNet\test\test\MainWindow.xaml 123
If I put backgroundBrush directly into app.xaml like so:
<Application.Resources>
<ResourceDictionary>
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary Source="/;component/Theme/Colors.xaml" />
<ResourceDictionary Source="/;component/Theme/Styles.xaml" />
<ResourceDictionary>
<SolidColorBrush x:Key="backgroundBrush" Color="Gold"/>
</ResourceDictionary>
</ResourceDictionary.MergedDictionaries>
</ResourceDictionary>
</Application.Resources>
DesignView has no problems.
So is there a way to tell DesignView where to find backgroundBrush, if this brush is placed into a seperate resource dictionary?
Thats the problem with StaticResource isnt it. It needs the resource key resolved explicitly using shared \ merged \ direct resource dictionaries hierarchically up.
There are two options...
merge Colors.xaml dictionary in Styles.xaml
OR
in Styles.xaml refer the bursh using DynamicResource.
In case Resources are in different assemblies than that where MainWindow resides and the one dictionary is refering to the other dictionary. In that case reference is not resolved. This bug is already reported at Microsoft site in case your target framework is 4.0. However they have provided a workaround for it. Simply add the empty style in your Resource dictionaries and it will work fine like this -
<Application.Resources>
<ResourceDictionary>
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary Source="/;component/Theme/Colors.xaml" />
<ResourceDictionary Source="/;component/Theme/Styles.xaml" />
</ResourceDictionary.MergedDictionaries>
<Style TargetType="{x:Type Window}"/>
</ResourceDictionary>
</Application.Resources>
For further refernce please look at this link - https://connect.microsoft.com/VisualStudio/feedback/details/555322/global-wpf-styles-are-not-shown-when-using-2-levels-of-references#details
Try
{StaticResource ApplicationPageBackgroundThemeBrush}
for your status bar background value