Hallo,

ich verstehe nicht, warum der UI-Thread blockiert. Kann mir das jemand erklären?

#region Async
        private async void cmdProgrammLaden_Click(object sender, EventArgs e)
        {
            Console.WriteLine("Button-Thread-ID: " + Thread.CurrentThread.ManagedThreadId);
            this.txtSendData.Text = await DncProgrammLadenAsync();
        }

        async Task<string> DncProgrammLadenAsync()
        {
            string path     = String.Empty;
            string content  = String.Empty;
            
            using (OpenFileDialog openFileDialog = new OpenFileDialog())
            {
                openFileDialog.InitialDirectory = @"c:\Test\";
                openFileDialog.Filter = "Textdateien (*.txt)|*.txt";
                openFileDialog.FilterIndex = 2;
                openFileDialog.RestoreDirectory = true;

                if (openFileDialog.ShowDialog()==DialogResult.OK)
                {
                    path = openFileDialog.FileName;
                    var filestream = openFileDialog.OpenFile();

                    using (StreamReader reader = new StreamReader(filestream))
                    {
                        Console.WriteLine("Task-Thread-ID: "+Thread.CurrentThread.ManagedThreadId);
                        content = await reader.ReadToEndAsync();
                        //Thread.Sleep(3000);
                    }   
                }
                        return content;
                        
            }

        }
        #endregion Async

Ich bin im .NET-Framework unterwegs (4.7.2)

Grüße