Android跳转系统相机或相册获取图片

public class MainActivity extends Activity {

 private static final int PHOTO_REQUEST_CAREMA = 1;// 拍照
   private static final int PHOTO_REQUEST_GALLERY = 2;// 从相册中选择
 private static final int PHOTO_REQUEST_CUT = 3;// 结果

private ImageView iv_image;

 /* 头像名称 */
 private static final String PHOTO_FILE_NAME = "temp_photo.jpg";
 private File tempFile;

 @Override
 protected void onCreate(Bundle savedInstanceState) {
     super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
  this.iv_image = (ImageView) this.findViewById(R.id.iv_image);
 }

   /*
  * 从相册获取
  */
public void gallery(View view) {
     // 激活系统图库，选择一张图片
     Intent intent = new Intent(Intent.ACTION_PICK);
     intent.setType("image/*");
    // 开启一个带有返回值的Activity，请求码为PHOTO_REQUEST_GALLERY
      startActivityForResult(intent, PHOTO_REQUEST_GALLERY);
 }

 /*
 * 从相机获取
  */
 public void camera(View view) {
     // 激活相机
     Intent intent = new Intent("android.media.action.IMAGE_CAPTURE");
   // 判断存储卡是否可以用，可用进行存储
    if (hasSdcard()) {
       tempFile = new File(Environment.getExternalStorageDirectory(),
                PHOTO_FILE_NAME);
       // 从文件中创建uri
      Uri uri = Uri.fromFile(tempFile);
       intent.putExtra(MediaStore.EXTRA_OUTPUT, uri);
    }
    // 开启一个带有返回值的Activity，请求码为PHOTO_REQUEST_CAREMA
    startActivityForResult(intent, PHOTO_REQUEST_CAREMA);
 }

 /*
  * 剪切图片
 */
private void crop(Uri uri) {
    // 裁剪图片意图
    Intent intent = new Intent("com.android.camera.action.CROP");
   intent.setDataAndType(uri, "image/*");
    intent.putExtra("crop", "true");
     // 裁剪框的比例，1：1
     intent.putExtra("aspectX", 1);
      intent.putExtra("aspectY", 1);
     // 裁剪后输出图片的尺寸大小
     intent.putExtra("outputX", 250);
      intent.putExtra("outputY", 250);

   intent.putExtra("outputFormat", "JPEG");// 图片格式
     intent.putExtra("noFaceDetection", true);// 取消人脸识别
     intent.putExtra("return-data", true);
      // 开启一个带有返回值的Activity，请求码为PHOTO_REQUEST_CUT
     startActivityForResult(intent, PHOTO_REQUEST_CUT);
 }

 /*
  * 判断sdcard是否被挂载
  */
 private boolean hasSdcard() {
     if (Environment.getExternalStorageState().equals(
             Environment.MEDIA_MOUNTED)) {
        return true;
     } else {
        return false;
     }
 }

 @Override
 protected void onActivityResult(int requestCode, int resultCode, Intent data) {
     if (requestCode == PHOTO_REQUEST_GALLERY) {
         // 从相册返回的数据
         if (data != null) {
             // 得到图片的全路径
             Uri uri = data.getData();
            crop(uri);
         }

    } else if (requestCode == PHOTO_REQUEST_CAREMA) {
         // 从相机返回的数据
         if (hasSdcard()) {
            crop(Uri.fromFile(tempFile));
         } else {
             Toast.makeText(MainActivity.this, "未找到存储卡，无法存储照片！", 0).show();
         }

   } else if (requestCode == PHOTO_REQUEST_CUT) {
         // 从剪切图片返回的数据
         if (data != null) {
            Bitmap bitmap = data.getParcelableExtra("data");
           this.iv_image.setImageBitmap(bitmap);
       }
         try {
           // 将临时文件删除
            tempFile.delete();
        } catch (Exception e) {
             e.printStackTrace();
         }

   }

    super.onActivityResult(requestCode, resultCode, data);
 }
 }