private void save_Click(object sender, EventArgs e) { if (BitmapByHandle == null) { return; } SaveFileDialog saveDlg = new SaveFileDialog(); saveDlg.Title = "保存为"; saveDlg.OverwritePrompt = true; saveDlg.Filter = "BMP文件 (*.bmp) | *.bmp|" + "Gif文件 (*.gif) | *.gif|" + "JPEG文件 (*.jpg) | *.jpg|" + "PNG文件 (*.png) | *.png"; saveDlg.ShowHelp = true; if (saveDlg.ShowDialog() == DialogResult.OK) { string fileName = saveDlg.FileName; string strFilExtn = fileName.Remove(0, fileName.Length - 3); switch (strFilExtn) { case "bmp": BitmapByHandle.Save(fileName, System.Drawing.Imaging.ImageFormat.Bmp); break; case "jpg": BitmapByHandle.Save(fileName, System.Drawing.Imaging.ImageFormat.Jpeg); break; case "gif": BitmapByHandle.Save(fileName, System.Drawing.Imaging.ImageFormat.Gif); break; case "tif": BitmapByHandle.Save(fileName, System.Drawing.Imaging.ImageFormat.Tiff); break; case "png": BitmapByHandle.Save(fileName, System.Drawing.Imaging.ImageFormat.Png); break; default: break; } } }