'宣言 Property Progress As C1.Document.AsyncOperationProgressHandler(Of TResult,TProgress)
'使用法 Dim instance As IAsyncOperationWithProgress(Of TResult,TProgress) Dim value As C1.Document.AsyncOperationProgressHandler(Of TResult,TProgress) instance.Progress = value value = instance.Progress
C1.Document.AsyncOperationProgressHandler<TResult,TProgress> Progress {get; set;}