根据这个:http://developer.android.com/preview/features/runtime-permissions.html#coding一个应用程序可以检查运行时权限和请求权限,如果它还没有被授予。弹出如下对话框:

如果用户拒绝一个重要的权限,在我看来,应用程序应该显示一个解释为什么需要权限和什么影响拒绝。该对话框有两个选项:

重试(再次请求许可) 拒绝(应用程序将工作没有该许可)。

但是,如果用户选中“Never ask again”,则不应该显示带有解释的第二个对话框,特别是如果用户之前已经拒绝了一次。 现在的问题是:我的应用程序如何知道用户是否选中了Never ask again?IMO onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults)没有给我这个信息。

第二个问题是:谷歌是否计划在权限对话框中包含一个自定义消息,以解释为什么应用程序需要权限?这样就不会出现第二个对话框,这肯定会带来更好的用户体验。


当前回答

我还想知道用户是否选择了“never ask again”。我已经实现了一个“几乎解决方案”与一个丑陋的旗帜,但在我告诉你如何,我将告诉你我的动机:

I would like to offer the permission referring functionality initially. If the user uses it and has no rights, he/she gets the either the 1th dialog from above or both the 2nd and 3rd. When the user has chosen 'Never ask again' I would like to disable the functionality and to display it differently. - My action is triggered by a spinner text entry, I would also like to add '(Permission revoked)' to the label text displayed. This shows to the user: 'There is functionality but I cannot use it, due to my permission settings.' However, this does not seem to be possible, as I cannot check whether or not 'Never ask again' has been chosen.

I came to a solution I can live with by having my functionality always enabled with an active permission check. I am showing a Toast message in onRequestPermissionsResult() in case of a negative response but only if I have not shown my custom rationale popup. So if the user has chosen 'Never ask again' he gets a toast message only. If the user is reluctant to chose 'never ask again' he gets only the custom rationale and the permission request popup by the operation system but not toast, as three notifications in a row would be too much pain.

其他回答

你可以在onRequestPermissionsResult()中检查shouldShowRequestPermissionRationale()。

https://youtu.be/C8lUdPVSzDk?t=2m23s

在onRequestPermissionsResult()中检查权限是否被授予。如果不是,检查shouldShowRequestPermissionRationale()。

如果此方法返回true,则说明为什么需要此特定权限。然后根据用户的选择再次请求permissions()。 如果它返回false,则显示一个错误消息,权限未授予,应用程序不能继续前进或特定功能被禁用。

下面是示例代码。

@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
    super.onRequestPermissionsResult(requestCode, permissions, grantResults);
    switch (requestCode) {
        case STORAGE_PERMISSION_REQUEST:
            if (grantResults.length > 0
                    && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                // permission was granted :)
                downloadFile();
            } else {
                // permission was not granted
                if (getActivity() == null) {
                    return;
                }
                if (ActivityCompat.shouldShowRequestPermissionRationale(getActivity(), Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
                    showStoragePermissionRationale();
                } else {
                    Snackbar snackbar = Snackbar.make(getView(), getResources().getString(R.string.message_no_storage_permission_snackbar), Snackbar.LENGTH_LONG);
                    snackbar.setAction(getResources().getString(R.string.settings), new View.OnClickListener() {
                        @Override
                        public void onClick(View v) {
                            if (getActivity() == null) {
                                return;
                            }
                            Intent intent = new Intent();
                            intent.setAction(Settings.ACTION_APPLICATION_DETAILS_SETTINGS);
                            Uri uri = Uri.fromParts("package", getActivity().getPackageName(), null);
                            intent.setData(uri);
                            OrderDetailFragment.this.startActivity(intent);
                        }
                    });
                    snackbar.show();
                }
            }
            break;
    }
}

显然,谷歌maps对位置许可正是这样做的。

我必须实现相机的动态权限。有三种可能的情况:允许2。否认,3。别再问了。

 @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {

    for (String permission : permissions) {
        if (ActivityCompat.shouldShowRequestPermissionRationale(getActivity(), permission)) {
            //denied
            Log.e("denied", permission);
        } else {
            if (ActivityCompat.checkSelfPermission(getActivity(), permission) == PackageManager.PERMISSION_GRANTED) {
                //allowed
                Log.e("allowed", permission);
            } else {
                //set to never ask again
                Log.e("set to never ask again", permission);
                //do something here.
            }
        }
    }
    if (requestCode != MaterialBarcodeScanner.RC_HANDLE_CAMERA_PERM) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        return;
    }
    if (grantResults.length != 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
        mScannerView.setResultHandler(this);
        mScannerView.startCamera(mCameraId);
        mScannerView.setFlash(mFlash);
        mScannerView.setAutoFocus(mAutoFocus);
        return;
    } else {
        //set to never ask again
        Log.e("set to never ask again", permissions[0]);
    }
    DialogInterface.OnClickListener listener = new DialogInterface.OnClickListener() {
        public void onClick(DialogInterface dialog, int id) {
            dialog.cancel();
        }
    };
    AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
    builder.setTitle("Error")
            .setMessage(R.string.no_camera_permission)
            .setPositiveButton(android.R.string.ok, listener)
            .show();


}

private void insertDummyContactWrapper() {
        int hasWriteContactsPermission = checkSelfPermission(Manifest.permission.CAMERA);
        if (hasWriteContactsPermission != PackageManager.PERMISSION_GRANTED) {
            requestPermissions(new String[]{Manifest.permission.CAMERA},
                    REQUEST_CODE_ASK_PERMISSIONS);
            return;
        }
        mScannerView.setResultHandler(this);
        mScannerView.startCamera(mCameraId);
        mScannerView.setFlash(mFlash);
        mScannerView.setAutoFocus(mAutoFocus);
    }

private int checkSelfPermission(String camera) {
    if (ContextCompat.checkSelfPermission(getActivity(), Manifest.permission.CAMERA)
            != PackageManager.PERMISSION_GRANTED) {
        return REQUEST_CODE_ASK_PERMISSIONS;
    } else {
        return REQUEST_NOT_CODE_ASK_PERMISSIONS;
    }
}

在阅读了一些答案后,我发现了许多冗长而令人困惑的答案 我的结论是

if (!ActivityCompat.shouldShowRequestPermissionRationale(this,Manifest.permission.READ_EXTERNAL_STORAGE))
                Toast.makeText(this, "permanently denied", Toast.LENGTH_SHORT).show();

我有点晚了,我也遇到过类似的问题。解决此问题如下

假设您需要位置权限

请求权限启动器

private final ActivityResultLauncher<String> requestPermissionLauncher =
      registerForActivityResult(
          new RequestPermission(),
          isGranted -> {
            if (isGranted) {
              // Permission is granted go ahead
            } else {
              shouldShowRequestPermissionRationale();
            }
          });

权限检查

  private boolean hasPermissions() {
        if (checkSelfPermission(requireActivity(), ACCESS_FINE_LOCATION) == PERMISSION_GRANTED) {
          // Permission is granted go ahead
        } else {
          requestPermissionLauncher.launch(ACCESS_FINE_LOCATION);
        }
      }

检查是否需要显示权限理性/自定义对话来教育用户

private void shouldShowRequestPermissionRationale() {
        if (!shouldShowRequestPermissionRationale(ACCESS_FINE_LOCATION)) {
          // need to show permission rational custom dialog.
        } 
    }

shouldShowRequestPermissionRationale()方法可以用来检查用户是否选择了“never asked again”选项并拒绝了权限。 有很多代码示例,所以我宁愿解释如何将它用于这样的目的,因为我认为它的名称和实现使它比实际情况更加复杂。

正如在运行时请求权限中解释的那样,如果选项“never ask again”可见,该方法返回true,否则返回false;因此,它在第一次显示对话框时返回false,然后从第二次开始返回true,只有当用户拒绝选择该选项的权限时,它才会再次返回false。

要检测这种情况,您可以检测序列false-true-false,或者(更简单)您可以使用一个标记来跟踪对话框显示的初始时间。在此之后,该方法返回true或false,其中false将允许您检测何时选择该选项。