Setting WPF image source in code

Question

I'm trying to set a WPF image's source in code. The image is embedded as a resource in the project. By looking at examples I've come up with the below code. For some reason it doesn't work - the image does not show up.

By debugging I can see that the stream contains the image data. So what's wrong?

Assembly asm = Assembly.GetExecutingAssembly();
Stream iconStream = asm.GetManifestResourceStream("SomeImage.png");
PngBitmapDecoder iconDecoder = new PngBitmapDecoder(iconStream, BitmapCreateOptions.PreservePixelFormat, BitmapCacheOption.Default);
ImageSource iconSource = iconDecoder.Frames[0];
_icon.Source = iconSource;

The icon is defined something like this: <Image x:Name="_icon" Width="16" Height="16" />

Solution 1

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.

Solution 2

var uriSource = new Uri(@"/WpfApplication1;component/Images/Untitled.png", UriKind.Relative);
foo.Source = new BitmapImage(uriSource);

This will load a image called "Untitled.png" in a folder called "Images" with its "Build Action" set to "Resource" in an assembly called "WpfApplication1".

Solution 3

This is a bit less code and can be done in a single line.

string packUri = "pack://application:,,,/AssemblyName;component/Images/icon.png";
_image.Source = new ImageSourceConverter().ConvertFromString(packUri) as ImageSource;

Solution 4

Very easy:

To set a menu item's image dynamically, only do the following:

MyMenuItem.ImageSource = 
    new BitmapImage(new Uri("Resource/icon.ico",UriKind.Relative));

...whereas "icon.ico" can be located everywhere (currently it's located in the 'Resources' directory) and must be linked as Resource...

Solution 5

Simplest way:

var uriSource = new Uri("image path here");
image1.Source = new BitmapImage(uriSource);

View more solutions

Comments

[Torbjørn]

LOL! Why make it easy when you first can make it difficult :) I'll try your simple solution before I accept though...

[Torbjørn]

Actually this didn't help me at all. Maybe I'm stupid :( Don't have time to look more closely right now (pet project). Would like more answers for when I get back to it :)

[si618]

Thanks for that. One issue that tripped me up as a noob to wpf, image must be marked as resource for this to work.

[Torbjørn]

Yes, this was the solution I found myself after some trial and error. Thanks for the thorough explanation. Answer accepted!

[Torbjørn]

I don't know why this was needed though, and why the other answers didn't work for me...

[Thomas Stock]

the other answers in this and other questions didn't work for me either. This one works perfectly. Thanks.

[gjvdkamp]

Shorter = better. I had to set it as @"/folder/image.png" though but then it worked fine. Thanks!

[Sangram Nandkhile]

This solution Gave me an exception so i tried Jared Harley's solution and it worked...

[Qwertie]

Okay, but isn't there some method or class that the XAML parser uses to convert the simple path string to an ImageSource? Couldn't we just use that?

[Qwertie]

I think the problem is that WPF doesn't "like" the traditional approach of putting resources in resx files. Instead you are supposed to add the image directly to your project and set its Build Action property to Resource. I'm don't know what the difference is (in term physical file format) between the two approaches.

[Jerry Nixon]

Ensure the Build Action is Content

[Sven]

the most important thing is "UriKind.RelativeOrAbsolute" - other examples always threw exceptions

[Hamzeh Soboh]

var uriSource = new Uri("Images/Untitled.png", UriKind.Relative); would be sufficient

[joshcomley]

This is definitely the best answer, utilising .NETs own implementation

[Scott Solmer]

This solution doesn't work for me. I get a compile error: Cannot implicitly convert type System.Windows.Media.Imaging.BitmapImage to System.Windows.Controls.Image...

[hkarask]

Add the image to the grid from toolbox, add a name to it (e.g. TestImage) and set the image path from properties menu. Then write var testImage = TestImage to startup code, add a breakpoint, debug and copy the source value.

[pStan]

... and much easier. Thanks Hamzeh

[secretgenes]

what if we need to set the height and width of image i.e icon.png? Because by using _image.height and _image.width it sets the image window not the actual image i.e icon.png.

[HaloMediaz]

When I assign the imagesource, it's just showing up blank :(

[Myosotis]

BeginInit() doesn't seem to exist in WPF.

[maulik kansara]

It is available check below link msdn.microsoft.com/en-us/library/…

[Clemens]

I often see this snippet copied into other posts, where people usually ignore the existence of the BitmapImage(Uri) constructor, which helps to avoid the need for calling BeginInit and EndInit. I've added it here.

[Rouzbeh Zarandi]

@HaloMediaz path may be wrong ....eg you have Resources but you you may write it Resource

[Psiloc]

This worked for me, and far more straightforward than the absolute URIs in the other answers.

[Slate]

This solution didn't work for me, however appending pack://application:,,, to the Uri does.

[mins]

Question: "The image is embedded as a resource in the project", answer: "Here is an example [for an image] located somewhere on disc rather than build as resource".

[Yessir]

Where do i get the assembly name from?

[Daniel Möller]

Great solution. Can easily return a string and use Binding without caring about the assembly name.