Clipboard.SetDataObject method regression in .NET 9.0.100-rc.2

[akhromushkin]

Description

Clipboard.SetDataObject method doesn't place a custom DataObject into the clipboard.

Reproduction Steps

1. Create a .NET Framework WinForms (or WPF) project.
2. Create a custom DataObject class descendant:

    public class SomeDataObject : DataObject {
        public static string Format = "SomeDataObjectId";
        public override string[] GetFormats() {
            return new string[] { Format };
        }
    }

3. Call the Clipboard.SetDataObject(new SomeDataObject()); method to add the SomeDataObject's class instance into the clipboard.

Expected behavior

SomeDataObject is added into the clipboard

And Clipboard.GetDataObject().GetDataPresent(SomeDataObject.Format) is true

Actual behavior

The clipboard doesn't contain the SomeDataObject instance

And Clipboard.GetDataObject().GetDataPresent(SomeDataObject.Format) is false

Regression?

Yes, in .NET 8 everything works.

Known Workarounds

No response

Impact

No response

Configuration

$ dotnet --info
.NET SDK:
 Version:           9.0.100-rc.2.24474.11
 Commit:            315e1305db
 Workload version:  9.0.100-manifests.4872d5d5
 MSBuild version:   17.12.0-preview-24473-03+fea15fbd1

Runtime Environment:
 OS Name:     Windows
 OS Version:  10.0.22631
 OS Platform: Windows
 RID:         win-x64
 Base Path:   C:\Program Files\dotnet\sdk\9.0.100-rc.2.24474.11\

Host:
  Version:      9.0.0-rc.2.24473.5
  Architecture: x64
  Commit:       990ebf52fc

.NET SDKs installed:
  9.0.100-rc.2.24474.11 [C:\Program Files\dotnet\sdk]

.NET runtimes installed:
  Microsoft.AspNetCore.App 9.0.0-rc.2.24474.3 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
  Microsoft.NETCore.App 9.0.0-rc.2.24473.5 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
  Microsoft.WindowsDesktop.App 9.0.0-rc.2.24474.4 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]

Other information

No response

[miloush]

Please include a repro project. This seems like an unusual way to use data objects. Perhaps the regression is because of the binary formatter removal? https://devblogs.microsoft.com/dotnet/binaryformatter-removed-from-dotnet-9/.

[Kuldeep-MS]

@akhromushkin After following your reproduction steps, I encountered the error shown below. Could you please provide more detailed steps?

[akhromushkin]

Perhaps is more related to WinForms. So I have attached several projects:
Issue_10049_WPF.zip
Issue_10049_WinForms.zip

[BlueBSH]

This issue still exists in the RTM GA version of .NET9.0.0

[miloush]

This is all Winforms classes and should be moved to the Winforms repo.