Clipboard.SetContent Throwing COMException

[nlogozzo]

Describe the bug

When calling Clipboard.SetContent(package) I am getting the following error AND THE TEXT IS NOT COPIED TO CLIPBOARD:

System.Runtime.InteropServices.COMException: 'CoInitialize has not been called. (0x800401F0 (CO_E_NOTINITIALIZED))'

System.Runtime.InteropServices.COMException
  HResult=0x800401F0
  Message=CoInitialize has not been called. (0x800401F0 (CO_E_NOTINITIALIZED))
  Source=WinRT.Runtime
  StackTrace:
   at WinRT.ExceptionHelpers.<ThrowExceptionForHR>g__Throw|20_0(Int32 hr)
   at ABI.Windows.ApplicationModel.DataTransfer.IClipboardStaticsMethods.SetContent(IObjectReference _obj, DataPackage content)
   at Windows.ApplicationModel.DataTransfer.Clipboard.SetContent(DataPackage content)
   at NickvisionTubeConverter.WinUI.Controls.DownloadRow.<ViewLog>d__28.MoveNext() in C:\Users\nlogo\OneDrive\Documents\Programming\Parabolic\NickvisionTubeConverter.WinUI\Controls\DownloadRow.xaml.cs:line 216

Steps to reproduce the bug

Here is my code:

private async void ViewLog(object sender, RoutedEventArgs e)
{
    var logDialog = new ContentDialog()
    {
        Title = _("Log"),
        Content = new ScrollViewer()
        {
            MaxHeight = 200,
            Content = new TextBlock()
            {
                Margin = new Thickness(0, 0, 14, 0),
                Text = _log,
                TextWrapping = TextWrapping.WrapWholeWords
            }
        },
        PrimaryButtonText = _("Copy to Clipboard"),
        CloseButtonText = _("OK"),
        DefaultButton = ContentDialogButton.Close,
        XamlRoot = _xamlRoot
    };
    var res = await logDialog.ShowAsync();
    if(res == ContentDialogResult.Primary)
    {
        var package = new DataPackage();
        package.SetText(_log);
        Clipboard.SetContent(package);
    }
}

It basically shows the _log variable in a ContentDialog with an option to copy it to the clipboard. Upon hitting the line Clipboard.SetContent(package) is when the error is thrown.

Expected behavior

The text is copied to the clipboard without any error thrown.

Screenshots

No response

NuGet package version

Windows App SDK 1.4.2: 1.4.231008000

Packaging type

Unpackaged

Windows version

Windows 11 version 22H2 (22621, 2022 Update)

IDE

Visual Studio 2022

Additional context

No response

[castorix]

There is a similar issue at : #8892

[nlogozzo]

Making the app single instance seems to have caused the issue.

I followed this guide for making single instance: https://blogs.windows.com/windowsdeveloper/2022/01/28/making-the-app-single-instanced-part-3/

And this issue for the solution: https://learn.microsoft.com/en-us/answers/questions/780749/winui-3-clipboard-api-not-working

Seems like the single instance guide should be updated to not use async main...or at least have a fix for using async main and clipboard

[bogdan-patraucean]

You just need to run SetContent on a different thread than the UI one, that's how it works with single instancing.

[FoggyFinder]

You just need to run SetContent on a different thread than the UI one, that's how it works with single instancing.

why so? is it documented somewhere?

[julian-baumann]

Since the two years this little bug was reported, has there been any successful workaround for the latest WinUI version? Spawning a new Thread does not work...

[julian-baumann]

So, apparently it works, when executed on the main thread. Just tried it.

[julian-baumann]

on which exact windows build version?

I'm not quite sure which one you mean, but my target framework is net9.0-windows10.0.19041.0 and my PC is running OS build 22631.5039

also, Is your App "Single Instanced"?

No, I just used the standard winUI 3 template, I believe.

Here is the working code in action. This code gets called, when clicking on a notification button. Maybe this is an issue?