权限对话框未显示6.0

Question

我想获得android.permission.WRITE_SETTINGS权限以在那里切换值。看一下我得到这段代码的文档后，它根本没有显示对话框。

在授予权限时，我调用AlarmManager来启动BroadcastReceiver，我在startAlarm方法上执行。但是我觉得它与我的问题无关。

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    SeePermissions();


}

public void SeePermissions(){
    // Here, thisActivity is the current activity
    if (ContextCompat.checkSelfPermission(this,
            Manifest.permission.WRITE_SETTINGS)
            != PackageManager.PERMISSION_GRANTED) {

        // Should we show an explanation?
        if (ActivityCompat.shouldShowRequestPermissionRationale(this,
                Manifest.permission.WRITE_SETTINGS)) {

        } else {
            // No explanation needed, we can request the permission.
            ActivityCompat.requestPermissions(this,
                    new String[]{Manifest.permission.WRITE_SETTINGS},
                    MY_PERMISSIONS_REQUEST_WRITE_SETTINGS);
        }
    }
}

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

                Intent alarmIntent=new Intent(this, AlarmReceiver.class);
                enableNightMode = PendingIntent.getBroadcast(this, 123, alarmIntent, PendingIntent.FLAG_UPDATE_CURRENT);
                startAlarm();

            } else {

                Toast.makeText(getApplicationContext(),"NO",Toast.LENGTH_SHORT).show();
            }
            return;
        }

    }
}