Develop Reference

Accessing elements in a xaml defined style

I have followed the DiagramDesigner example on Codeproject for learning how to use Adorners in WPF as it fits quite a few of my needs relatively closely.
I have adapted the implementation a little, and also added my own adorner, for controlling the opacity of a control via a slider (slider on the adorner).
Following the same methods as the author, I placed the slider and other feature in a xaml style definition file as below. I am just now struggling A) to figure out how to access the slider at any level, B) how best to start hooking this up with an underlying Viewmodel that will be used for various settings (on adorners).
<Style x:Key="OpacityAdorner" TargetType="{x:Type adorners:OpacityChrome}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type adorners:OpacityChrome}">
<Grid>
<Slider x:Name="OpacitySlider" Style="{StaticResource OpacityControl}" ToolTip="Alter the opacity of the image to overlay with other images" Visibility="Collapsed"/>
<Ellipse x:Name="OpacitySliderEnable" Style="{StaticResource OpacityIcon}" ToolTip="Alter the visual opacity of the image" Visibility="Visible"/>
</Grid>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
The codeproject example is here http://www.codeproject.com/Articles/22952/WPF-Diagram-Designer-Part

A) Use something like the following snippet to get the slider from the applied template.
var slider = opacityAdorner.Template.FindName("OpacitySlider", opacityAdorner) as Slider;
there are cases where the template has not yet been applied, in that case you need to preceed the previous call with the following:
opacityAdorner.ApplyTemplate();
B) The best approach for hooking up with the view model (in my opinion) is to expose the required properties as dependency properties on the OpacityChrome adorner. You then use normal Binding to hook up the new properties to the view-model, and TemplateBinding to hook them up to the template elements.

WPF Template Binding with more than 1 content

So, I have this Window. On it, I'm creating a list of TextBlocks and TextBoxes in pairs. When you click on either, they will put a number in the corresponding TextBox, and set some values in the background. This all works well now.
I have the following XAML to create a custom Checkbox (as it has the behavior I'd like to use for this). My problem is that I want to bind different content into both the TextBlock and TextBox. For the TextBlock, I bound to the Content property, but I can't find a suitable option to satisfy the second binding. I considered placing it in the tag, but this didn't feel right, and in any case, I'm already binding an index value I require into there.
<Style x:Key="CustomCHK" TargetType="{x:Type CheckBox}">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="{x:Type CheckBox}">
<DockPanel LastChildFill="True">
<TextBox DockPanel.Dock="Right" Width="50" Height="30" />
<TextBlock Text="{TemplateBinding Content}" TextWrapping="Wrap" />
</DockPanel>
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
Feels like there should a simple solution to this, but I'm just trying to decide what's best. Do I create a custom checkbox class and just add a couple properties?
As always, I appreciate any direction you can offer me.

Unfortunately, there is no straightforward way to do this. I can see just two (somewhat flawed) workarounds:
Subclass CheckBox to suit your needs, and add the additional content properties that you need. The advantage is that this will fully enable your IDE's programming help for setting the content properties, and those properties will be typesafe. The downside is that your will need to add C# code for the sole purpose of declaring the additional content properties (i.e. without adding any "behavioral logic"), which somehow seems to conflict with a "clean" XAML-only for presentation approach.
You could try passing an array to the Content property, and then place several ContentPresenter instances in your control template, each of which bind to another item in the array. Binding property paths should support indexed access, though your code may become a bit verbose, as arrays in XAML have to be written explicitly by using the x:Array markup extension.

How to add a svg/xaml file in C# WPF windows just like image?

How to add a .svg file in a WPF window in C# as an image (,png || ,jpg)?
I use the code
<Image HorizontalAlignment="Left" Height="53" Margin="34,39,0,0"
VerticalAlignment="Top" Width="71"
Source="Test.svg" Name="MyImage"/>
But I get an error:
Blend does not support format svg.
I found that I could change the .svg file into a .xaml file. But I still do not know how to add the xaml as an image.
Based on an answer, I changed my code like this:
<Window x:Class="NIA_UI_Demo_CSharp.ShareDocumentsWin"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:svgc="http://sharpvectors.codeplex.com/svgc/"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
Title="ShareDocumentsWin" Height="350" Width="569">
<ResourceDictionary>
<Style x:Key="TheAwesomeXAMLimage" TargetType="ContentControl">
<Setter Property="Template">
<Setter.Value>
<ControlTemplate TargetType="ContentControl">
my code
</ControlTemplate>
</Setter.Value>
</Setter>
</Style>
</ResourceDictionary>
<Grid Margin="0,0,2,3">
<ContentControl Style="{StaticResource TheAwesomeXAMLimage}"/>
</Grid>
</Window>
But I get an error:
Content is set more than once;

As far as I know you cannot include svg-files directly.
Two options:
use library that can handle svg-files in runtime: https://sharpvectors.codeplex.com/ (moved to https://github.com/ElinamLLC/SharpVectors)
convert the svg to xaml and use them with native wpf objects (Path, Image..)
I prefer the second option, so I wrote a tool which can convert a single svg to xaml and can also batch convert a bunch of svg-files. The workflow is: just put the svg-file to your images-folder, call the batch-converter and find the images.xaml file (a resource-dictionary) updated with the new icons/images.
See https://github.com/BerndK/SvgToXaml

I was lucky that I have DevExpress available where you can use WpfSvgRenderer.CreateImageSource. Don't want to advertise here, but since it's a widely used library, probably some are happy to know.
Unfortunately text element inside the svg is not supported yet.

Xaml: Finding a control defined within ControlTemplate from C# at ResourceDictionary level

Library.xaml
<ResourceDictionary>
<ControlTemplate x:Key="test" TargetType="{x:Type Button}">
<Button Width="200" Height="40" Name="my_custom_btn" Click="r_Click_1" Style="{StaticResource button_style}">Button</Button>
</ControlTemplate>
</ResourceDictionary>
I want to access this Button element defined within my ControlTemplate from my C# file when template is not applied in Main.xaml.
I have tried all methods
Template.FindName, Application.Current.Resource, Control.GetTemplateChild(), using VISUALTREE HELPER search but i am not getting this element in my c# code.
As far as I know these methods are used to find elements when a control template which is defined somewhere in Library.xaml is loaded in Main.xaml file by giving its TargetType.
But what if this template is not applied and Still I want to access its element from my code.
I have looking for a proper solution for a past few days. plz help!!
Please explain it fully as I am new to WPF..

WPF Using images in generic.xaml template

I am writing a style for a custom control derived directly from Control. Visual Studio places the style for a "Custom Control (WPF)" in the Themes\generic.xaml file. My style contains an image which I can't get displayed, seems there's something special about how to set the Source for an image from within the generic.xaml file.
I managed to reproduce the issue with a simpler scenario. Create a "WPF Custom Control library" then add a style for buttons like so, in the themes\generic.xaml . Here's my complete generic.xaml:
<ResourceDictionary
...
<Style TargetType="{x:Type Button}">
<Setter Property="Content">
<Setter.Value>
<Image Source="SmallHandle.png"></Image>
</Setter.Value>
</Setter>
</Style>
</ResourceDictionary>
After this I have create a UserControl (in the same project) containing just a button (for the sake of testing out the style) like so:
<UserControl x:Class="BlendControls.UserControl1"
...
mc:Ignorable="d"
d:DesignHeight="300" d:DesignWidth="300">
<Button/>
</UserControl>
I have added the SmallHandle.png in the root project directory, in the themes directory, I have added it also to the good old Resources page, tried changing the build action to resource, embedded resource, tried copying the image manually to the build directory, but to no effect. The image is never displayed.
This must be related to the generic.xaml file, because copying the entire style to the same file where the Button is placed works fine. That is, the following works as expected:
<UserControl x:Class="BlendControls.UserControl1"
...
d:DesignHeight="300" d:DesignWidth="300">
<UserControl.Resources>
<Style TargetType="{x:Type Button}">
<Setter Property="Content">
<Setter.Value>
<Image Source="SmallHandle.png"></Image>
</Setter.Value>
</Setter>
</Style>
</UserControl.Resources>
<Button></Button>
</UserControl>
So, how should I set the Source of images from generic.xaml? Or alternatively, where should I put the styles/templates for custom controls?
---- Solution ----
As pointed out by Sheridan, I have to use the "full" pack URI notation as:
pack://application,,,/MyAssembly;components/SmallHandle.png
This looks strange to me, as the image is in the same assembly. Not sure, looks like I am referencing from outside the dll.

There's nothing unusual about accessing an image in Generic.xaml, you're just not referencing it correctly. You can reference a resource file in the project assembly using this format:
<Image Source="/AssemblyName;component/Subfolder/SmallHandle.png" />
If your images are directly inside the project root (which is not recommended), then you can access them like this:
<Image Source="/AssemblyName;component/SmallHandle.png" />
If your images are in a folder in another project, then you can access it like this:
<Image Source="/ReferencedAssembly;component/Subfolder/SmallHandle.png" />
See the Pack URIs in WPF page on MSDN for more information.
UPDATE >>>
In .NET 4, the above Image.Source values would work. However, Microsoft made some horrible changes in .NET 4.5 that broke many different things and so in .NET 4.5, you'd need to use the full pack path like this:
<Image Source="pack://application:,,,/AssemblyName;component/Images/image_to_use.png">

If you don't feel as though your generic.xaml is being picked up, you can reference it from your App.cs.xaml like this:
<App.Resources>
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary Source="/MY.NAMESPACE;component/Themes/generic.xaml" />
</ResourceDictionary.MergedDictionaries>
</App.Resources>
Your generic.xaml file should be marked as "Resource".
Also, your image file should be marked as "Resource".
Finally, reference your ImageSource like this:
<Image Source="Themes/IMAGE.png" />
or try
<Image Source="../Themes/IMAGE.png" />
Personally, I like to put my style templates in their own .xaml file, and reference them all as MergedDictionaries.

Typed base style in Themes\Generic style is automatically applied only to Custom Control.
If you need use typed based style in your user control you need add generic.xaml to user control resources.
<UserControl.Resources>
<ResourceDictionary>
<ResourceDictionary.MergedDictionaries>
<ResourceDictionary Source="Themes/Generic.xaml" />
</ResourceDictionary.MergedDictionaries>
</ResourceDictionary>
</UserControl.Resources>
Also change Image Source URI to
<Image Source="pack://application:,,,/WpfCustomControlLibrary1;component/SmallHandle.png" />