@ricardobossan , please root-cause this issue and report back.

@Tanya-Solyanik My findings so far:

• The DataGridView Tasks dialog is displayed through the DesignerActionPanel.
• The DataSource value shown there comes from the designer class, specifically DataGridViewDesigner.
• The value of DataSource starts as null. If the user changes it to None in the dropdown, it is set back to null.
• When the value is null, the field appears empty in the Tasks dialog.
• A practical workaround is to return the string "(none)" when the DataSource property of DataGridViewDesigner is null, like so:

  public object? DataSource
  {
      get => _owner.DataSource ?? "(none)";
  }

We shouldn't replace a null return value with a string, this is a public API, the customers are expecting and handling a null. How is this supposed to work? how does it work in the Inproc designer or OOP designer? Does this work when demo console is retargeted to NETFX?

How is this supposed to work? how does it work in the Inproc designer or OOP designer?

• On OOP, I debugged a standard .NET 10 WinForms project (VPN on), and the "(none)" message appeared as expected in the field:
  
• I found one place where the string "(none)" appears during runtime. This seems to be the value returned from serialization:
  
• Here’s the call stack for that serialization:

  > Microsoft.DotNet.DesignTools.Protocol.dll!Microsoft.DotNet.DesignTools.Protocol.DataPipe.Binary.BinaryMessageFormatter.StreamJsonRpc.IJsonRpcMessageFormatter.Serialize(System.Buffers.IBufferWriter<byte> bufferWriter, StreamJsonRpc.Protocol.JsonRpcMessage message) Line 158 C#
  >
  > StreamJsonRpc.dll!StreamJsonRpc.LengthHeaderMessageHandler.Write(StreamJsonRpc.Protocol.JsonRpcMessage content, System.Threading.CancellationToken cancellationToken) Unknown
  > StreamJsonRpc.dll!StreamJsonRpc.MessageHandlerBase.WriteAsync(StreamJsonRpc.Protocol.JsonRpcMessage content, System.Threading.CancellationToken cancellationToken) Unknown
  > [Resuming Async Method]
  > System.Private.CoreLib.dll!System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start<StreamJsonRpc.MessageHandlerBase.<WriteAsync>d**23>(ref StreamJsonRpc.MessageHandlerBase.<WriteAsync>d**23 stateMachine) Unknown
  > StreamJsonRpc.dll!StreamJsonRpc.JsonRpc.SendAsync(StreamJsonRpc.Protocol.JsonRpcMessage message, System.Threading.CancellationToken cancellationToken) Unknown
  > [Resuming Async Method]
  > System.Private.CoreLib.dll!System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start<StreamJsonRpc.JsonRpc.<SendAsync>d**149>(ref StreamJsonRpc.JsonRpc.<SendAsync>d**149 stateMachine) Unknown
  > StreamJsonRpc.dll!StreamJsonRpc.JsonRpc.HandleRpcAsync(StreamJsonRpc.Protocol.JsonRpcMessage rpc) Unknown
  > [Resuming Async Method]
  > System.Private.CoreLib.dll!System.Threading.ExecutionContext.RunInternal(System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, object state) Unknown
  > System.Private.CoreLib.dll!System.Runtime.CompilerServices.AsyncTaskMethodBuilder<System.Threading.Tasks.VoidTaskResult>.AsyncStateMachineBox<StreamJsonRpc.JsonRpc.<HandleRpcAsync>d**165>.MoveNext(System.Threading.Thread threadPoolThread) Unknown
  > System.Private.CoreLib.dll!System.Runtime.CompilerServices.TaskAwaiter.OutputWaitEtwEvents.AnonymousMethod**12_0(System.Action innerContinuation, System.Threading.Tasks.Task innerTask) Unknown
  > System.Private.CoreLib.dll!System.Threading.Tasks.AwaitTaskContinuation.RunOrScheduleAction(System.Action action, bool allowInlining) Unknown
  > System.Private.CoreLib.dll!System.Threading.Tasks.Task.RunContinuations(object continuationObject) Unknown
  > StreamJsonRpc.dll!StreamJsonRpc.JsonRpc.DispatchIncomingRequestAsync(StreamJsonRpc.Protocol.JsonRpcRequest request) Unknown
  > [Resuming Async Method]
  > System.Private.CoreLib.dll!System.Threading.ExecutionContext.RunInternal(System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, object state) Unknown
  > System.Private.CoreLib.dll!System.Runtime.CompilerServices.AsyncTaskMethodBuilder<StreamJsonRpc.Protocol.JsonRpcMessage>.AsyncStateMachineBox<StreamJsonRpc.JsonRpc.<DispatchIncomingRequestAsync>d**158>.MoveNext(System.Threading.Thread threadPoolThread) Unknown
  > System.Private.CoreLib.dll!System.Runtime.CompilerServices.TaskAwaiter.OutputWaitEtwEvents.AnonymousMethod**12_0(System.Action innerContinuation, System.Threading.Tasks.Task innerTask) Unknown
  > System.Private.CoreLib.dll!System.Threading.Tasks.AwaitTaskContinuation.RunOrScheduleAction(System.Action action, bool allowInlining) Unknown
  > System.Private.CoreLib.dll!System.Threading.Tasks.Task.RunContinuations(object continuationObject) Unknown
  > StreamJsonRpc.dll!StreamJsonRpc.JsonRpc.DispatchRequestAsync(StreamJsonRpc.Protocol.JsonRpcRequest request, StreamJsonRpc.TargetMethod targetMethod, System.Threading.CancellationToken cancellationToken) Unknown
  > [Resuming Async Method]
  > System.Private.CoreLib.dll!System.Threading.ExecutionContext.RunInternal(System.Threading.ExecutionContext executionContext, System.Threading.ContextCallback callback, object state) Unknown
  > System.Private.CoreLib.dll!System.Runtime.CompilerServices.TaskAwaiter.OutputWaitEtwEvents.AnonymousMethod\_\_12_0(System.Action innerContinuation, System.Threading.Tasks.Task innerTask) Unknown
  > System.Private.CoreLib.dll!System.Threading.Tasks.AwaitTaskContinuation.System.Threading.IThreadPoolWorkItem.Execute() Unknown
  > System.Private.CoreLib.dll!System.Threading.ThreadPoolWorkQueue.DispatchWorkItem(object workItem, System.Threading.Thread currentThread) Unknown
  > System.Private.CoreLib.dll!System.Threading.ThreadPoolWorkQueue.Dispatch() Unknown
  > System.Private.CoreLib.dll!System.Threading.PortableThreadPool.WorkerThread.WorkerThreadStart() Unknown
  > System.Private.CoreLib.dll!System.Threading.Thread.StartHelper.RunWorker() Unknown

Does this work when demo console is retargeted to NETFX?

• Yes, when I target DemoConsole to NETFX, the "(none)" message still appears normally, just as described in the original issue.

InProc designer will be closer to our demo console, please experiment with it as well.

Investigation on the InProc designer shows that the "(none)" string for the binding picker dialog appears only in the BindingFormattingDialog.resx file, in the dataSourcePicker.Text resource, as shown in the screenshot below:

This resource is only used within the BindingFormattingDialog, as illustrated here:

There is no corresponding BindingFormattingDialog or dataSourcePicker resource in the runtime repository.

So, while there is a structure for this in the InProc designer, I could not find any equivalent handling in the runtime repo.

Thank you, @ricardobossan, we can't port data source picker because it depends on other components. Could you please:

1. move DataGridViewChooseDataSourceActionList to a separate file
2. Add a comment to GetSortedActionItems that the choose data source designer action item is missing.
3. Then close this bug as not planned.