Question

错误讯息：

FATAL EXCEPTION: main
Process: com.example.keepair.myapplication, PID: 31796
java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=66536, result=0, data=null} to activity {com.example.keepair.myapplication/com.example.keepair.myapplication.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'android.net.Uri android.content.Intent.getData()' on a null object reference

代码：

    mGetImageFromGalleryButton = (Button) view.findViewById(R.id.btn_getgallery);
    mGetImageFromGalleryButton.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    if(ActivityCompat.checkSelfPermission(getActivity(),
                            Manifest.permission.READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED)
                    {
                        requestPermissions(
                                new String[]{Manifest.permission.READ_EXTERNAL_STORAGE},
                                2000);
                    }
                    else {
                        startGallery();
                    }
                }
            });

    private void startGallery() {
        Intent cameraIntent = new Intent(Intent.ACTION_PICK, MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
        cameraIntent.setType("image/*");
        if (cameraIntent.resolveActivity(getActivity().getPackageManager()) != null) {
            startActivityForResult(cameraIntent, 1000);
        }
    }

    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        if(resultCode == Activity.RESULT_OK) {
            if(requestCode == 1000){
                Uri returnUri = data.getData();
                Bitmap bitmapImage = null;
                try {
                    bitmapImage = MediaStore.Images.Media.getBitmap(getActivity().getContentResolver(), returnUri);
                } catch (IOException e) {
                    e.printStackTrace();
                }
                mImageview.setImageBitmap(bitmapImage);
            }
            returnUri = data.getData();
            Glide.with(this)
                .load(returnUri)
                .override(1280, 1280)
                .centerCrop()
                .crossFade()
                .into(mImageview);
        }
        else { #What is good for this space? }
    }

如果用户点击mGetImageFromGalleryButton中的GalleryFragment，我的代码会这样做，用户可以去图库并选择一张图片，然后使用该图片回到GalleryFragment \ uri

问题： 如果用户单击mGetImageFromGalleryButton然后转到图库，但不选择任何图片并单击android后退按钮，则上面说的Error message我发生了。所以，我想我必须修改public void onActivityResult上的if子句。如果我认为是正确的，那对else { #What is good for this space? }有什么好处你会帮助我吗？

Answer 1

如果不选择任何图像，则数据为空。这就是它给出错误的原因。如果您的数据不为空，请在代码周围添加条件。

E.g

if(data != null){

   //Proceed with your image crop etc

}

如果我没有选择任何图片并单击后退按钮，则会崩溃

2 个答案: