1: public override void FinishedPickingMedia(UIImagePickerController picker, NSDictionary info)

   2: {

   3:     //图片之前有方法读取了，这里主要是测试视频，下面是相册内的视频地址，很容易用代码得到的

   4:     //主要是在模拟器中选取视频，点击use后不能触发这个事件，不知道是不是模拟器的bug，所以固定下面视频地址，然后选择图片来执行下面代码

   5:     NSUrl referenceURL = new NSUrl("assets-library://asset/asset.mov?id=5F4A9F73-3542-469F-8DAD-BC2B53BFB40C&ext=mov");

   6:     if (referenceURL != null)

   7:     {

   8:         ThreadPool.QueueUserWorkItem(delegate

   9:         {

  10:             ALAssetsLibrary library = new ALAssetsLibrary();

  11:             library.AssetForUrl(referenceURL, (asset) =>

  12:             {

  13:                 if (asset != null)

  14:                 {

  15:                     string filePath1 = Path.Combine(destPath, asset.DefaultRepresentation.Filename);

  16:                     long size = asset.DefaultRepresentation.Size;

  17:                     byte[] imgData = new byte[size];

  18:                     NSError nsError;

  19:                     IntPtr buffer = Marshal.AllocHGlobal(imgData.Length);

  20:                     //拷贝ALAsset的一定字节到一个缓冲中

  21:                     asset.DefaultRepresentation.GetBytes(buffer, 0, (uint)size, out nsError);

  22:                     吧缓冲写入到byte

  23:                     Marshal.Copy(buffer, imgData, 0, imgData.Length);

  24:                     //可以写成文件，或发送字节流等动作

  25:                     File.WriteAllBytes(filePath1, imgData);

  26:                 }

  27:  

  28:             }, (error) =>

  29:             {

  30:                 if (error != null)

  31:                 {

  32:                     Console.WriteLine("错误: " + error.LocalizedDescription);

  33:                 }

  34:             });

  35:         });

  36:     }

  37:     picker.DismissModalViewControllerAnimated(true);

  38: }