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.
        } 
    }

扩展上面mVck的答案，下面的逻辑确定是否“Never ask again”已经为给定的权限请求进行了检查:

bool bStorage = grantResults[0] == Permission.Granted;
bool bNeverAskForStorage =
    !bStorage && (
        _bStorageRationaleBefore == true  && _bStorageRationaleAfter == false ||
        _bStorageRationaleBefore == false && _bStorageRationaleAfter == false
    );

摘自下面(完整的例子见这个答案)

private bool _bStorageRationaleBefore;
private bool _bStorageRationaleAfter;        
private const int ANDROID_PERMISSION_REQUEST_CODE__SDCARD = 2;
//private const int ANDROID_PERMISSION_REQUEST_CODE__CAMERA = 1;
private const int ANDROID_PERMISSION_REQUEST_CODE__NONE = 0;

public override void OnRequestPermissionsResult(int requestCode, string[] permissions, [GeneratedEnum] Permission[] grantResults)
{
    base.OnRequestPermissionsResult(requestCode, permissions, grantResults);

    switch (requestCode)
    {
        case ANDROID_PERMISSION_REQUEST_CODE__SDCARD:               
            _bStorageRationaleAfter = ShouldShowRequestPermissionRationale(Android.Manifest.Permission.WriteExternalStorage);
            bool bStorage = grantResults[0] == Permission.Granted;
            bool bNeverAskForStorage =
                !bStorage && (
                    _bStorageRationaleBefore == true  && _bStorageRationaleAfter == false ||
                    _bStorageRationaleBefore == false && _bStorageRationaleAfter == false
                );      
            break;                
    }
}

private List<string> GetRequiredPermissions(out int requestCode)
{
    // Android v6 requires explicit permission granting from user at runtime for security reasons            
    requestCode = ANDROID_PERMISSION_REQUEST_CODE__NONE; // 0
    List<string> requiredPermissions = new List<string>();

    _bStorageRationaleBefore = ShouldShowRequestPermissionRationale(Android.Manifest.Permission.WriteExternalStorage);
    Permission writeExternalStoragePerm = ApplicationContext.CheckSelfPermission(Android.Manifest.Permission.WriteExternalStorage);
    //if(extStoragePerm == Permission.Denied)
    if (writeExternalStoragePerm != Permission.Granted)
    {
        requestCode |= ANDROID_PERMISSION_REQUEST_CODE__SDCARD;
        requiredPermissions.Add(Android.Manifest.Permission.WriteExternalStorage);
    }

    return requiredPermissions;
}

protected override void OnCreate(Bundle savedInstanceState)
{
    base.OnCreate(savedInstanceState);

        // Android v6 requires explicit permission granting from user at runtime for security reasons
        int requestCode;
        List<string> requiredPermissions = GetRequiredPermissions(out requestCode);
        if (requiredPermissions != null && requiredPermissions.Count > 0)
        {
            if (requestCode >= ANDROID_PERMISSION_REQUEST_CODE__SDCARD)                    
            {
                _savedInstanceState = savedInstanceState;
                RequestPermissions(requiredPermissions.ToArray(), requestCode);
                return;
            }
        }
    }            

    OnCreate2(savedInstanceState);
}

public void onRequestPermissionsResult(int requestCode, @NonNull String permissions[], @NonNull int[] grantResults) {
    switch (requestCode) {
        case PERMISSIONS_REQUEST_EXTERNAL_STORAGE: {
            if (grantResults.length > 0) {
                if (ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
                    // Denied
                } else {
                    if (ActivityCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED) {
                        // To what you want
                    } else {
                       // Bob never checked click
                    }
                }
            }
        }
    }
}

试试这个简单的权限库。它将在3个简单的步骤中处理与权限相关的所有操作。这节省了我的时间。您可以在15分钟内完成所有权限相关的工作。

它可以处理拒绝，它可以处理永不再请求，它可以调用应用程序设置的权限，它可以给出一个Rational消息，它可以给出一个拒绝消息，它可以给出一个接受的权限列表，它可以给出一个拒绝的权限列表，等等。

https://github.com/ParkSangGwon/TedPermission

步骤1:添加依赖项

dependencies {
     compile 'gun0912.ted:tedpermission:2.1.1'
     //check the above link for latest libraries
}

步骤2:征求许可

TedPermission.with(this)
    .setPermissionListener(permissionlistener)
    .setDeniedMessage("If you reject permission,you can not use this service\n\nPlease turn on permissions at [Setting] > [Permission]")
    .setPermissions(Manifest.permission.READ_CONTACTS, Manifest.permission.ACCESS_FINE_LOCATION)
    .check();

步骤3:处理权限响应

PermissionListener permissionlistener = new PermissionListener() {
    @Override
    public void onPermissionGranted() {
        Toast.makeText(MainActivity.this, "Permission Granted", Toast.LENGTH_SHORT).show();
    }

    @Override
    public void onPermissionDenied(ArrayList<String> deniedPermissions) {
        Toast.makeText(MainActivity.this, "Permission Denied\n" + deniedPermissions.toString(), Toast.LENGTH_SHORT).show();
    }
};

这里有一个很好的和简单的方法来检查当前的权限状态:

    @Retention(RetentionPolicy.SOURCE)
    @IntDef({GRANTED, DENIED, BLOCKED_OR_NEVER_ASKED })
    public @interface PermissionStatus {}

    public static final int GRANTED = 0;
    public static final int DENIED = 1;
    public static final int BLOCKED_OR_NEVER_ASKED = 2;

    @PermissionStatus 
    public static int getPermissionStatus(Activity activity, String androidPermissionName) {
        if(ContextCompat.checkSelfPermission(activity, androidPermissionName) != PackageManager.PERMISSION_GRANTED) {
            if(!ActivityCompat.shouldShowRequestPermissionRationale(activity, androidPermissionName)){
                return BLOCKED_OR_NEVER_ASKED;
            }
            return DENIED;
        }
        return GRANTED;
    }

警告:在用户通过用户提示接受/拒绝权限之前，在第一个应用程序启动时返回BLOCKED_OR_NEVER_ASKED(在sdk 23+设备上)

更新:

Android支持库现在似乎也有一个非常类似的类Android .support.v4.content。PermissionChecker，包含checkSelfPermission()，返回:

public static final int PERMISSION_GRANTED = 0;
public static final int PERMISSION_DENIED = -1;
public static final int PERMISSION_DENIED_APP_OP = -2;

如果你想检测所有的“状态”(第一次被拒绝，刚刚被拒绝，刚刚被“Never Ask Again”拒绝或永久拒绝)，你可以做以下事情:

创建2个布尔值:

private boolean beforeClickPermissionRat;
private boolean afterClickPermissionRat;

在请求允许之前设置第一个:

beforeClickPermissionRat = shouldShowRequestPermissionRationale(Manifest.permission.READ_EXTERNAL_STORAGE);

在你的onRequestPermissionsResult方法中设置第二个:

afterClickPermissionRat = shouldShowRequestPermissionRationale(Manifest.permission.READ_EXTERNAL_STORAGE);

使用下面的“真值表”在onRequestPermissionsResult()中做任何你需要的事情(在检查你仍然没有权限之后):

// before after
// FALSE  FALSE  =  Was denied permanently, still denied permanently --> App Settings
// FALSE  TRUE   =  First time deny, not denied permanently yet --> Nothing
// TRUE   FALSE  =  Just been permanently denied --> Changing my caption to "Go to app settings to edit permissions"
// TRUE   TRUE   =  Wasn't denied permanently, still not denied permanently --> Nothing