Android onRequestPermissionsResult对我的片段不起作用

Question

在我活动页面之一的片段中，我希望从用户处获得权限，并在授予权限后执行一些操作，但OnRequestPermissionsResult不起作用，且在授予权限后看不到任何日志

public class FragmentAboutUs extends Fragment implements ActivityCompat.OnRequestPermissionsResultCallback {
    private Activity          activity;
    private Context           context;
    ...
    private int WRITE_EXTERNAL_STORAGE = 1;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
    }

    @Override

    public View onCreateView(LayoutInflater inflater, final ViewGroup container,
                             Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_about_us, container, false);

        activity = getActivity();
        context = getActivity().getBaseContext();

        ...

        aboutUs = SQLite.select().from(AboutUs.class).querySingle();
        if (aboutUs == null) {
            if (ActivityCompat.checkSelfPermission(context, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
                if (ActivityCompat.shouldShowRequestPermissionRationale(activity, Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
                    ActivityCompat.requestPermissions(activity, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, WRITE_EXTERNAL_STORAGE);
                } else {
                    ActivityCompat.requestPermissions(activity, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, WRITE_EXTERNAL_STORAGE);
                }
            }
        }
        return view;
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        if (requestCode == WRITE_EXTERNAL_STORAGE) {
            Log.e("permission granted"," OK");
        } else {
            super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        }
    }
}

Answer 1

删除此：

implements ActivityCompat.OnRequestPermissionsResultCallback

片段本身可以处理运行时权限的OnRequestPermissionsResultCallback:

使用方法如下：

 final int MyVersion = Build.VERSION.SDK_INT;
if (MyVersion > Build.VERSION_CODES.LOLLIPOP_MR1) {
        if (!checkIfAlreadyhavePermission()) {
            requestPermissions(new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE }, WRITE_EXTERNAL_STORAGE);  //request permission
        } else {
            //call your method permision already granted
        }
    } else {
            //call your method permission not needed for this version
    }


private boolean checkIfAlreadyhavePermission() {
        int result = ContextCompat.checkSelfPermission(getActivity(), Manifest.permission.WRITE_EXTERNAL_STORAGE);
        return result == PackageManager.PERMISSION_GRANTED;
    }

现在，您可以在片段内部的public void onRequestPermissionsResult()中获取权限结果

使用：

public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
    switch (requestCode) {
        case WRITE_EXTERNAL_STORAGE: {
            // If request is cancelled, the result arrays are empty.
            if (grantResults.length > 0
                    && grantResults[0] == PackageManager.PERMISSION_GRANTED) {

                Toast.makeText(getActivity(), "permission granted", Toast.LENGTH_LONG).show();
                //call your action

            } else {
                Toast.makeText(getActivity(), "permission denied", Toast.LENGTH_LONG).show();
            }
            break;
        }
    }
}