Question

I have found some evidence that this is possible,

self.scene = Canvas() Application.LoadComponent(self.scene, Uri('app.xaml', UriKind.Relative)) 

but my code is failing:

class Program {     [STAThread]     static void Main(string[] args)     {         Canvas scene = new Canvas();         Application.LoadComponent(scene, new Uri('app.xaml', UriKind.Relative));     } } 

I am using the same app.xaml with ‘Build Action: None’, and ‘Copy always’.

<Canvas     xmlns='http://schemas.microsoft.com/winfx/2006/xaml/presentation'     xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml'     x:Class='System.Windows.Controls.Canvas'     x:Name='ball_design' >      <Canvas x:Name='workaround_canvas' >          <TextBlock x:Name='fps' Canvas.Left='10' Canvas.Top='10' Height='40' Canvas.ZIndex='10000' Text='-- fps' />     <Canvas x:Name='wpfe_ball_0' Width='52' Height='52' Canvas.Left='0' Canvas.Top='30'>       <!-- Layer 3/<Group>/<Path> -->       <Path Opacity='0.900000' StrokeThickness='2.000000' Stroke='#ffa6d000' StrokeMiterLimit='1.000000' Fill='#ffcbff00' Data='F1 M 51.000000,26.000000 C 51.000000,39.806641 39.807129,51.000000 26.000000,51.000000 C 12.192871,51.000000 1.000000,39.806641 1.000000,26.000000 C 1.000000,12.193359 12.192871,1.000000 26.000000,1.000000 C 39.807129,1.000000 51.000000,12.193359 51.000000,26.000000 Z'/>        <!-- Layer 3/<Group>/<Path> -->       <Path Opacity='0.740000' Data='F1 M 43.143066,13.087891 C 50.602051,22.888672 49.009766,36.642578 39.590332,43.812500 C 30.170898,50.980469 16.489258,48.842773 9.032715,39.042969 C 1.573242,29.240234 3.166016,15.486328 12.584961,8.316406 C 22.003906,1.149414 35.685547,3.285156 43.143066,13.087891 Z'>         <Path.Fill>           <RadialGradientBrush MappingMode='Absolute' GradientOrigin='156.791016,170.453125' Center='156.791016,170.453125' RadiusX='53.626404' RadiusY='53.626404'>             <RadialGradientBrush.GradientStops>               <GradientStop Offset='0.000000' Color='#ffffffff'/>               <GradientStop Offset='0.361685' Color='#fff5f7dd'/>               <GradientStop Offset='0.415730' Color='#ffebf0bc'/>               <GradientStop Offset='1.000000' Color='#ffcbff00'/>             </RadialGradientBrush.GradientStops>             <RadialGradientBrush.Transform>               <MatrixTransform Matrix='1.190000,0.165000,-0.165000,-1.281300,-113.414185,241.757843' />             </RadialGradientBrush.Transform>           </RadialGradientBrush>         </Path.Fill>       </Path>        <!-- Layer 3/<Group>/<Path> -->       <Path Fill='#ffffffff' Data='F1 M 23.100586,9.477539 C 24.741699,11.634766 23.116211,15.630859 19.470703,18.404297 C 15.825684,21.178711 11.540039,21.678711 9.899414,19.522461 C 8.258301,17.365234 9.883789,13.369141 13.529297,10.594727 C 17.174316,7.821289 21.459961,7.321289 23.100586,9.477539 Z'/>     </Canvas>     <TextBlock x:Name='dbgwin' FontSize='10' Canvas.Top='10' Canvas.Left='250' Height='500' Width='200' Text='IronPython DLR' />    </Canvas> </Canvas> 

I get IOException: Cannot locate resource ‘app.xaml’.

What is a solution?

Answer 1

It seems that external XAML file can’t be loaded by LoadComponent.

I checked the source code:

    public static void LoadComponent(Object component, Uri resourceLocator)      {         ...          // Passed a relative Uri here.         // needs to resolve it to Pack://Application.         //..\..\ in the relative Uri will get stripped when creating the new Uri and resolving to the          //PackAppBaseUri, i.e. only relative Uri within the appbase are created here         Uri currentUri = new Uri(BaseUriHelper.PackAppBaseUri, resourceLocator);           ...     } 

So the resourceLocator SHOULD be a relative path. And it will be treated under application:/// authority.

MSDN

WPF supports two authorities: application:/// and siteoforigin:///. The application:/// authority identifies application data files that are known at compile time, including resource and content files. The siteoforigin:/// authority identifies site of origin files.

Possible data files are:

• Packages and parts are analogous to applications and files, where an application (package) can include one or more files (parts), including:

• Resource files that are compiled into the local assembly.

• Resource files that are compiled into a referenced assembly.

• Resource files that are compiled into a referencing assembly.

• Content files.

• Site of origin files.

The first 4 files are accessible with application://, but I am looking for external files, so the only option is ‘Content file’.

So I turned app.xaml into content file (details are here)

1. Build Action to Content
2. Copy to Output Directory to Copy always
3. [assembly: AssemblyAssociatedContentFile(‘app.xaml’)]

As result such exception was thrown: ‘application/xaml+xml’ ContentType is not valid.

    public static void LoadComponent(Object component, Uri resourceLocator)      {         ...              if (!MimeTypeMapper.BamlMime.AreTypeAndSubTypeEqual(contentType))              {                 throw new Exception(SR.Get(SRID.ContentTypeNotSupported, contentType));              }         ...     } 

So the LoadComponent expects ‘application/baml+xml’ instead of ‘application/xaml+xml’.

I don’t know a way to store xaml as external file in ‘application/baml+xml’, so assume the task has no solution.