Wpf – Load Image at runtime from resource in WPF

wpf

Im trying to load a image at runtime in WPF using the following code

_image = new Image();
BitmapImage src = new BitmapImage();
src.BeginInit();
src.UriSource = new Uri(@"pack://application:,,,/images/tagimages/placeholder.png", UriKind.Absolute);                
src.CacheOption = BitmapCacheOption.OnLoad;
src.EndInit();
_image.Source = src;
_image.Stretch = Stretch.None;

In my project I have a folder called images and a sub folder of that folder called tagimages that contains the placeholder.png. When I run this code I get the following error

"Cannot locate resource 'images/tagimages/placeholder.png'"

What am I doing wrong?

Best Answer

It turns out that I should have used

Uri(@"pack://application:,,,/<MyProject>;component/images/tagimages/placeholder.png", UriKind.Absolute);

Related Solutions

C# – Setting WPF image source in code

After having the same problem as you and doing some reading, I discovered the solution - Pack URIs.

I did the following in code:

Image finalImage = new Image();
finalImage.Width = 80;
...
BitmapImage logo = new BitmapImage();
logo.BeginInit();
logo.UriSource = new Uri("pack://application:,,,/AssemblyName;component/Resources/logo.png");
logo.EndInit();
...
finalImage.Source = logo;

Or shorter, by using another BitmapImage constructor:

finalImage.Source = new BitmapImage(
    new Uri("pack://application:,,,/AssemblyName;component/Resources/logo.png"));

The URI is broken out into parts:

Authority: application:///
Path: The name of a resource file that is compiled into a referenced assembly. The path must conform to the following format: AssemblyShortName[;Version][;PublicKey];component/Path
- AssemblyShortName: the short name for the referenced assembly.
- ;Version [optional]: the version of the referenced assembly that contains the resource file. This is used when two or more referenced assemblies with the same short name are loaded.
- ;PublicKey [optional]: the public key that was used to sign the referenced assembly. This is used when two or more referenced assemblies with the same short name are loaded.
- ;component: specifies that the assembly being referred to is referenced from the local assembly.
- /Path: the name of the resource file, including its path, relative to the root of the referenced assembly's project folder.

The three slashes after application: have to be replaced with commas:

Note: The authority component of a pack URI is an embedded URI that points to a package and must conform to RFC 2396. Additionally, the "/" character must be replaced with the "," character, and reserved characters such as "%" and "?" must be escaped. See the OPC for details.

And of course, make sure you set the build action on your image to Resource.

Wpf – How to get a BitmapImage from a Resource

This MSDN page has all the information you might want to know about resource URIs in WPF (often called pack URIs). You're going to want to use relative URIs more often probably, so see Table 4, which should be of particular use.

If you want a briefer overview of resource (pack) URIs, see this blog post. It shows that syntax is indeed relatively simple:

pack://application:,,,/ResourceFile.xaml

pack://application:,,,/ReferencedAssembly;component/ResourceFile.xaml

However, there are a few quirks to work out (in my experience), so often finding the correct resource URI requires a bit of experimentation.

Best Answer

Related Solutions

C# – Setting WPF image source in code

Wpf – How to get a BitmapImage from a Resource

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