public void startCamera2(View view){
        Intent intent=new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
//        Uri photoUri = Uri.fromFile(new File(mFilePath));//显示的路径有权限风险
        photoUri = FileProvider.getUriForFile(
                this,
                getPackageName() + ".provider",
                new File(mFilePath));
        intent.putExtra(MediaStore.EXTRA_OUTPUT,photoUri); //更改照片存储路径到photoUri
        startActivityForResult(intent,REQ_2);   //打开相机拍照，返回相机结果（照片）并回到原界面
    }
    //onActivityResult部分代码
    else if(requestCode == REQ_2){
                FileInputStream fis = null;
                try {
                    fis = new FileInputStream(new File(mFilePath));
                    Bitmap bitmap = BitmapFactory.decodeStream(fis);  //涉及写入内存卡权限，在manifest里面配置

//                    Bitmap bitmap = BitmapFactory.decodeStream(getContentResolver().openInputStream(photoUri));
                    mImageView.setImageBitmap(bitmap);           //从内存读取原图