Android-请求权限对话框不出现在请求权限之后（活动、权限[]、请求代码）

Question

我一直在尝试实现运行时权限。下面是它的代码片段：

RunTimePermissionsUtil。JAVA

package com.orgzit.android.util;

import android.app.Activity;
import android.content.Context;
import android.content.pm.PackageManager;
import android.os.Build;
import android.support.v4.app.ActivityCompat;

public class RuntimePermissionsUtil {

private static boolean shouldAskPermission() {
    return (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M);
}

private static boolean shouldAskPermission(Context context, String permission) {
    if (shouldAskPermission()) {
        int permissionGrantedResult = ActivityCompat.checkSelfPermission(context, permission);
        return !(permissionGrantedResult == PackageManager.PERMISSION_GRANTED);
    }
    return false;
}

//TODO Karan 2018-09-20 Still need to investigate on the behaviour of storing in SharedPreferences whether I have asked for the permission before or not
public static void checkPermission(Context context, String permission, AskPermissionListener permissionListener) {
    if (shouldAskPermission(context, permission)) {
        if (!ActivityCompat.shouldShowRequestPermissionRationale(((Activity)context), permission)) {
            permissionListener.onNeedPermission();
        } else {
            permissionListener.onPermissionDisabled();
        }
    } else {
        permissionListener.onPermissionGranted();
    }
}

public interface AskPermissionListener {

    void onPermissionGranted();

    void onNeedPermission();

    void onPermissionDisabled();
}
}

在一个名为AddFileActivity的活动中，我在一个点击事件中实现了这个监听器，其代码如下：

public class AddFileActivity extends DrawerActivity {

private static final int CAMERA_REQ_CODE = 1001;
private static final int FILE_SELECT_REQ_CODE = 1002;

private Activity activity;

private RuntimePermissionsUtil.AskPermissionListener askPermissionListener;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    activity = this;
    init();
    getSupportActionBar().setTitle("Add File");

    askPermissionListener = new RuntimePermissionsUtil.AskPermissionListener() {
        @Override
        public void onPermissionGranted() {
            Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
            cameraFileUri = getCameraFileUri();
            intent.putExtra(MediaStore.EXTRA_OUTPUT, cameraFileUri);
            startActivityForResult(intent, CAMERA_REQ_CODE);
        }

        @Override
        public void onNeedPermission() {
            ActivityCompat.requestPermissions(activity, new String[]{Manifest.permission.CAMERA}, CAMERA_REQ_CODE);
        }

        @Override
        public void onPermissionDisabled() {
            Toast.makeText(activity,"App does not have the permission to Open Camera :(", Toast.LENGTH_LONG).show();
        }
    };
}

@Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
    Log.d("q","q");
}

private void init() {
            showFileChooser();
}


private void showFileChooser() {
    final CharSequence[] items = {"Open camera", "Select from device",
            "Cancel"};
    AlertDialog.Builder builder = new AlertDialog.Builder(AddFileActivity.this);
    builder.setItems(items, new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int item) {
            if (items[item].equals("Open camera")) {
                RuntimePermissionsUtil.checkPermission(activity, Manifest.permission.CAMERA, askPermissionListener);
                Log.d("d","d");
            } else if (items[item].equals("Select from device")) {
                //DO SOMETHING
            } else if (items[item].equals("Cancel")) {
                dialog.dismiss();
            }
        }
    });
    builder.show();
}

所以，我所有的代码都会执行，它会进入onNeed权限（）代码，其中，它会进入

ActivityCompat.requestPermissions(activity, new String[]{Manifest.permission.CAMERA}, CAMERA_REQ_CODE);

但是，令人惊讶的是，在此之后，没有任何对话框要求获得摄像头的运行时权限，相反，对话框关闭并再次显示活动。

有没有人能帮我解决这个问题，或者指出一个克服它的方法

Answer 1

权限请求对话框未出现的原因有：

• 要么许可已经被授予
• 或者权限已设置为不再询问
• 或者你还没有在舱单上声明许可

在所有情况下，都会立即调用onRequestPermissionsResult（），而不显示对话框。检查它是否被调用，并检查结果。

与其编写自己的实用程序类，我建议您看看我的库：https://github.com/nabinbhandari/Android-Permissions