public static void showImagePickDialog(final Activity activity){

 String title = "选择获取图片方式";
 String[] items = new String[]{"拍照","相册"};

 new AlertDialog.Builder(activity)
  .setTitle(title)
  .setItems(items, new DialogInterface.OnClickListener() {
   @Override
   public void onClick(DialogInterface dialog, int which) {

     dialog.dismiss();
     switch (which){
       case 0:
       //选择拍照
       pickImageFromCamera(activity);
       break;
       case 1:
       //选择相册
       pickImageFromAlbum(activity);
       break;
       default:
       break;
      }
     }
    }).show();
 }

public static void pickImageFromCamera(final Activity activity){
 //获得指定路径的Uri
 imageUriFromCamera = getImageUri();

 Intent intent = new Intent();
 intent.setAction(MediaStore.ACTION_IMAGE_CAPTURE);
 intent.putExtra(MediaStore.EXTRA_OUTPUT,imageUriFromCamera);
 activity.startActivityForResult(intent,REQUEST_CODE_FROM_CAMERA);
}

public static void pickImageFromAlbum(final Activity activity){

  //隐式调用，可能出现多种选择
  Intent intent = new Intent();
  intent.setAction(Intent.ACTION_GET_CONTENT);
  intent.setType("image/*");
  activity.startActivityForResult(intent,REQUEST_CODE_FROM_ALBUM);
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
  super.onActivityResult(requestCode, resultCode, data);

  switch (requestCode){
   case ImageUtils.REQUEST_CODE_FROM_ALBUM: {

    if (resultCode == RESULT_CANCELED) { //取消操作
     return;
    }

    Uri imageUri = data.getData();
    ImageUtils.copyImageUri(this,imageUri); //复制图片
    ImageUtils.cropImageUri(this, ImageUtils.getCurrentUri(), 200, 200); //裁剪图片
    break;
   }
   case ImageUtils.REQUEST_CODE_FROM_CAMERA: {

    if (resultCode == RESULT_CANCELED) { //取消操作
     ImageUtils.deleteImageUri(this, ImageUtils.getCurrentUri()); //删除Uri
    }

    ImageUtils.cropImageUri(this, ImageUtils.getCurrentUri(), 200, 200); //裁剪图片
    break;
   }
   case ImageUtils.REQUEST_CODE_CROP: {

    if (resultCode == RESULT_CANCELED) { //取消操作
     return;
    }

    Uri imageUri = ImageUtils.getCurrentUri();
    if (imageUri != null) {
     imageView.setImageURI(imageUri); //显示图片
    }
    break;
   }
   default:
    break;
  }
 }