btn8.setOnClickListener(new View.OnClickListener() {
      @Override
      public void onClick(View view) {
/*在Activity Action里面有一个“ACTION_GET_CONTENT”字符串常量，
// 该常量让用户选择特定类型的数据，并返回该数据的URI.我们利用该常量，
//然后设置类型为“image/*”，就可获得Android手机内的所有image。*/
        Intent intent = new Intent();
        /* 开启Pictures画面Type设定为image */
        intent.setType("image/*");
        /* 使用Intent.ACTION_GET_CONTENT这个Action */
        intent.setAction(Intent.ACTION_GET_CONTENT);
        /* 取得相片后返回本画面 */
        startActivityForResult(intent, 1);


//Intent intent = new Intent(Intent.ACTION_PICK, android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
// startActivityForResult(intent, RESULT);
      }
    });



 @Override
  protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    if (resultCode == RESULT_OK) {
      Uri uri = data.getData();
      Log.e("uri", uri.toString());
      ContentResolver cr = this.getContentResolver();
      try {
        Bitmap bitmap = BitmapFactory.decodeStream(cr.openInputStream(uri));
        /* 将Bitmap设定到ImageView */
        iv8.setImageBitmap(bitmap);
      } catch (FileNotFoundException e) {
        Log.e("Exception", e.getMessage(), e);
      }
    }
    super.onActivityResult(requestCode, resultCode, data);
  }