Launcher

The Launcher service allows you to open a file, folder, or URI in the default application associated with that item. For example, you can use it to open a URL in the user's default browser, or open a document in the application registered to handle its file type.

You can access the Launcher through an instance of TopLevel or Window. For more details on accessing TopLevel, visit the TopLevel page.

var launcher = TopLevel.GetTopLevel(control).Launcher;

Methods

LaunchUriAsync

Starts the default application associated with the URI scheme name for the specified URI.

Task<bool> LaunchUriAsync(Uri uri)

note

The input URI can have any scheme, including custom ones. However, it is up to the operating system to accept or deny the launcher request.

Example: opening a URL in the default browser

var success = await launcher.LaunchUriAsync(new Uri("https://avaloniaui.net"));

LaunchFileAsync

Starts the default application associated with the specified storage file or folder.

Task<bool> LaunchFileAsync(IStorageItem storageItem);

note

IStorageItem is a file or folder retrieved from sandboxed APIs such as IStorageProvider or IClipboard. If you only target non-sandboxed desktop platforms, consider using the extension methods that accept FileInfo or DirectoryInfo instead.

Example: opening a file picked by the user

var files = await storageProvider.OpenFilePickerAsync(new FilePickerOpenOptions());
if (files.Count > 0)
{
    await launcher.LaunchFileAsync(files[0]);
}

Extension methods

The following extension methods are available for convenience when you are targeting non-sandboxed desktop platforms (Windows, macOS, Linux).

LaunchFileInfoAsync

Starts the default application associated with the specified file.

Task<bool> LaunchFileInfoAsync(FileInfo fileInfo)

Example

var file = new FileInfo("/path/to/document.pdf");
var success = await launcher.LaunchFileInfoAsync(file);

LaunchDirectoryInfoAsync

Starts the default application associated with the specified directory (folder). This typically opens the folder in the system file manager.

Task<bool> LaunchDirectoryInfoAsync(DirectoryInfo directoryInfo);

Example

var folder = new DirectoryInfo("/path/to/folder");
var success = await launcher.LaunchDirectoryInfoAsync(folder);

Return values

Each of these methods returns a bool indicating whether the operating system was able to handle the request. A return value of true does not guarantee that an application actually opened the item. It only indicates that the OS accepted the request without error.

Platform compatibility

Feature	Windows	macOS	Linux	Browser	Android	iOS
LaunchUriAsync	✓	✓	✓	✓	✓	✓
LaunchFileAsync	✓	✓	✓	✗	✓	✓
LaunchFileInfoAsync	✓	✓	✓	✗	✗	✗
LaunchDirectoryInfoAsync	✓	✓	✓	✗	✗	✗

See also

• Storage Provider: File and folder management API.
• Clipboard: Reading and writing clipboard data.
• TopLevel: Accessing platform services from controls.