private void button2_Click(object sender, EventArgs e)
{
var foldPath = textBox1.Text.Trim();
if (string.IsNullOrEmpty(foldPath))
{
return;
}
ImageZoomThread(foldPath);
}

private void ImageZoomThread(string foldPath){ThreadStart threadStart = delegate { listBox1.Items.Clear(); ZoomImage(foldPath); };Thread thread = new Thread(threadStart);thread.IsBackground = true;thread.Start();}

 private void ZoomImage(string foldPath){DirectoryInfo dir = new DirectoryInfo(foldPath);FileInfo[] files = dir.GetFiles("*.jpg");DirectoryInfo[] dii = dir.GetDirectories();  foreach (var file in files){listBox1.Items.Add(file.FullName);listBox1.SelectedIndex = -1;ChangeImageSize(file.FullName, file.FullName.Replace(".jpg", "_zoom.jpg"));}//获取子文件夹内的文件列表，递归遍历  foreach (DirectoryInfo d in dii){ZoomImage(d.FullName);}  }/// <summary>/// 压缩图片/// </summary>/// <param name="filePath">要压缩的图片的路径</param>/// <param name="newfilePath">压缩后的图片的路径</param>public void ChangeImageSize(string filePath, string newfilePath){Bitmap bmp = null;ImageCodecInfo ici = null;System.Drawing.Imaging.Encoder ecd = null;EncoderParameter ept = null;EncoderParameters eptS = null;try{ici = this.getImageCoderInfo("image/jpeg");ecd = System.Drawing.Imaging.Encoder.Quality;eptS = new EncoderParameters(1);ept = new EncoderParameter(ecd, 35L);eptS.Param[0] = ept;if (File.Exists(newfilePath)){File.Delete(newfilePath);}bmp = new Bitmap(filePath);bmp.Save(newfilePath, ici, eptS);if (bmp != null)bmp.Dispose();ept.Dispose();eptS.Dispose();}catch (Exception ex){//throw new Exception(ex.Message);}finally{}}/// <summary>/// 获取图片编码类型信息/// </summary>/// <param name="coderType">编码类型</param>/// <returns>ImageCodecInfo</returns>private ImageCodecInfo getImageCoderInfo(string coderType){ImageCodecInfo[] iciS = ImageCodecInfo.GetImageEncoders();ImageCodecInfo retIci = null;foreach (ImageCodecInfo ici in iciS){if (ici.MimeType.Equals(coderType))retIci = ici;}return retIci;}