android - 如何在运行时权限中获取 "Never ask Again"选项

Question

在我的应用程序中，我创建了一个名为 Untility 的类，我在其中编写了 READ_EXTERNAL_STORAGE 权限代码。但问题是当我在应用程序上单击“拒绝”时，我没有找到警报通知来再次设置它允许。最初我有“不再询问”选项。单击它后，对话框消失了。现在在运行应用程序后，如果我单击拒绝，我将无法再找到对话框消息以使其再次允许。如何修改我的代码以每次都显示此消息。

我的工具类是

public class Utility {

public static final int MY_PERMISSIONS_REQUEST_READ_EXTERNAL_STORAGE = 123;

@TargetApi(Build.VERSION_CODES.M)
public static boolean checkPermission(final Context context) {
    int currentAPIVersion = Build.VERSION.SDK_INT;
    if (currentAPIVersion >= android.os.Build.VERSION_CODES.M) {
        if (ContextCompat.checkSelfPermission(context, Manifest.permission.READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
            if (ActivityCompat.shouldShowRequestPermissionRationale((Activity) context, Manifest.permission.READ_EXTERNAL_STORAGE)) {
                Log.v("TAG", "Permission is granted");
            }
            else {
                ActivityCompat.requestPermissions((Activity) context, new String[]{Manifest.permission.READ_EXTERNAL_STORAGE}, MY_PERMISSIONS_REQUEST_READ_EXTERNAL_STORAGE);
            }
            return false;
        } else {
            return true;
        }
    } else {
        return true;
    }
 }

我在这里调用 Utility 类的另一个类是

@Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
    switch (requestCode) {
        case Utility.MY_PERMISSIONS_REQUEST_READ_EXTERNAL_STORAGE:
            if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                if(userChoosenTask.equals("Take Photo"))
                    cameraIntent();
                else if(userChoosenTask.equals("Choose from Library"))
                    galleryIntent();

                    //do something here
            } else {
                //code for deny
                Toast.makeText(DetailMyColleague.this, "Permission Denied", Toast.LENGTH_SHORT).show();
            }
            break;
    }
}
private void selectImage() {
    final CharSequence[] items = { "Take Photo", "Choose from Library",
            "Cancel" };

    AlertDialog.Builder builder = new AlertDialog.Builder(DetailMyColleague.this);
    builder.setTitle("Add Photo!");
    builder.setItems(items, new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int item) {
            boolean result=Utility.checkPermission(DetailMyColleague.this);

            if (items[item].equals("Take Photo")) {
                userChoosenTask ="Take Photo";
                if(result)
                    cameraIntent();

            } else if (items[item].equals("Choose from Library")) {
                userChoosenTask ="Choose from Library";
                if(result)
                    galleryIntent();

            } else if (items[item].equals("Cancel")) {
                dialog.dismiss();
            }
        }
    });
    builder.show();
}
private void galleryIntent()
{
    Intent intent = new Intent();
    intent.setType("image/*");
    intent.setAction(Intent.ACTION_GET_CONTENT);//
    startActivityForResult(Intent.createChooser(intent, "Select File"),SELECT_FILE);
}
private void cameraIntent()
{
    Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
    startActivityForResult(intent, REQUEST_CAMERA);
}
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);

    if (resultCode == Activity.RESULT_OK) {
        if (requestCode == SELECT_FILE)
            onSelectFromGalleryResult(data);
        else if (requestCode == REQUEST_CAMERA)
            onCaptureImageResult(data);
    }
}

private void onCaptureImageResult(Intent data) {
    Bitmap thumbnail = (Bitmap) data.getExtras().get("data");
    ByteArrayOutputStream bytes = new ByteArrayOutputStream();
    thumbnail.compress(Bitmap.CompressFormat.JPEG, 90, bytes);

    File destination = new File(Environment.getExternalStorageDirectory(),
            System.currentTimeMillis() + ".jpg");

    FileOutputStream fo;
    try {
        destination.createNewFile();
        fo = new FileOutputStream(destination);
        fo.write(bytes.toByteArray());
        fo.close();
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }

    profilePic.setImageBitmap(thumbnail);
}
@SuppressWarnings("deprecation")
private void onSelectFromGalleryResult(Intent data) {

    Bitmap bm=null;
    if (data != null) {
        try {
            bm = MediaStore.Images.Media.getBitmap(getApplicationContext().getContentResolver(), data.getData());
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    profilePic.setImageBitmap(bm);
}

Answer 1

一旦他们说“不再询问”，您就无法显示相同的请求消息，但您可以检查权限，如果被拒绝，则显示一个自定义对话框，将他们定向到设置页面，目的是:

startActivityForResult(new Intent(android.provider.Settings.ACTION_SETTINGS), 0);

如果您的权限检查失败:

if (ContextCompat.checkSelfPermission(context, Manifest.permission.READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
    // show a dialog
    new AlertDialog.Builder(this).setMessage("You need to enable permissions to use this feature").setPositiveButton("Go to settings", new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {
            // navigate to settings
            startActivityForResult(new Intent(android.provider.Settings.ACTION_SETTINGS), 0);
        }
    }).setNegativeButton("Go back", new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {
            // leave?
            MyActivity.this.onBackPressed();
        }
    }).show();
}