public void Convert() { var ffMpeg = new FFMpegConverter(); comboBox1.InvokeIfRequired(GetComboBoxItem); ConvertSettings setting = new ConvertSettings(); //string sTargetType = (string)comboBox1.SelectedItem; string sTargetType = Combox1SelectItem; FieldInfo Info = VideoTypes.Where(x => x.Name == sTargetType).Select(y => y).FirstOrDefault(); setting.AudioSampleRate = 44100; label4.InvokeIfRequired(() => { label4.ForeColor = Color.Red; label4.Text = "轉檔中 請稍後"; }); try { ffMpeg.ConvertMedia(sSourceFile, null, sTargetFile + "." + Info.Name, Info.GetValue(null).ToString(), setting); } catch (Exception) { MessageBox.Show("轉檔失敗"); } Console.WriteLine("Finish"); //lambda非同步UI更新 btnConvert.InvokeIfRequired(() => { btnConvert.Enabled = true; }); TargetFile.InvokeIfRequired(() => { TargetFile.Enabled = false; }); label4.InvokeIfRequired(() => { label4.Text = "轉檔完畢,可以繼續進行下個轉換"; }); }