private void buttonModify_Click(object sender, EventArgs e) { if (!File.Exists(orgFileName)) { return; } try { var file = new PPT.Application().Presentations.Open(orgFileName, MsoTriState.msoTrue, MsoTriState.msoFalse, MsoTriState.msoFalse); foreach (PPT.Slide slide in file.Slides) { foreach (PPT.Shape shape in slide.Shapes) { if (shape.Type == MsoShapeType.msoMedia) { if (shape.MediaType == PPT.PpMediaType.ppMediaTypeMovie || shape.MediaType == PPT.PpMediaType.ppMediaTypeSound) { if (checkBoxVolume.Checked == true) { shape.MediaFormat.Volume = (float)numericUpDownVolume.Value / 100.0f; } if (radioButtonUnmuteAll.Checked == true) { shape.MediaFormat.Muted = false; } else if (radioButtonMuteAll.Checked == true) { shape.MediaFormat.Muted = true; } } } } } file.SaveAs(modifiedFileName); file.Close(); } catch (Exception ex) { MessageBox.Show(ex.Message); } }