Question

我正在尝试检查我的应用是否有权访问存储空间：

 if (ContextCompat.checkSelfPermission(SplashActivity.this, Manifest.permission.READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
        Toast.makeText(getBaseContext(), "merry christmas", Toast.LENGTH_LONG).show();
    }

这仅在清单中没有存储权限时才有效。当我添加权限时，它停止显示烤面包。似乎此代码检查清单是否具有权限，而不是是否授予了权限。我该如何解决？？

Answer 1

您必须使用以下代码手动请求用户允许权限。然后检查是否授予许可。

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    if(permitted()){
        // prompting permission dialog
        // permform your task
     }

 }


@Override
public void onResume() {
    super.onResume();
    if (permitted(PERMISSIONS))
        load();
}

@Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
    super.onRequestPermissionsResult(requestCode, permissions, grantResults);
    switch (requestCode) {
        case 1:
            if (permitted(permissions)) {
                load();
            } else {
                Toast.makeText(context, R.string.not_permitted, Toast.LENGTH_SHORT).show();
            }
    }
}
public static final String[] PERMISSIONS = new String[]{Manifest.permission.READ_EXTERNAL_STORAGE, Manifest.permission.WRITE_EXTERNAL_STORAGE};

boolean permitted(String[] ss) {
    for (String s : ss) {
        if (ContextCompat.checkSelfPermission(context, s) != PackageManager.PERMISSION_GRANTED) {
            return false;
        }
    }
    return true;
}

boolean permitted() {
    for (String s : PERMISSIONS) {
        if (ContextCompat.checkSelfPermission(context, s) != PackageManager.PERMISSION_GRANTED) {
            ActivityCompat.requestPermissions(getActivity(), PERMISSIONS, 1);
            return false;
        }
    }
    return true;
}

Answer 2

您的代码仅在未授予许可的情况下有效。如果未运行，则在安装过程中或从以前的apk数据中授予该权限。只需进入设置，选择您的应用并撤消权限，或者选择清除数据选项，然后重试。

Answer 3

这就是我的方法

   if (!checkPermission()) {  // this line checks permission everytime you access this activity
            Toast.makeText(context, R.string.not_permitted, Toast.LENGTH_SHORT).show();
       requestPermission();
   } else {
       enableGPS();
   }  




public boolean checkPermission() {
        int result = ContextCompat.checkSelfPermission(this, ACCESS_FINE_LOCATION);
        return result == PackageManager.PERMISSION_GRANTED;
    }

    public void requestPermission() {
        ActivityCompat.requestPermissions(this, new String[]{ACCESS_FINE_LOCATION}, REQUEST_CODE_ASK_PERMISSIONS);
    }  

@Override
    public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
        if (requestCode == REQUEST_CODE_ASK_PERMISSIONS) {
            if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                enableGPS();
            } else {
                Toast.makeText(getApplicationContext(), "Please allow access to continue!", Toast.LENGTH_SHORT).show();
            }
        }
    }

Answer 4

在应用程序级别gradle中添加以下依赖项，并同步您的项目。

implementaion 'com.nabinbhandari.android:permissions:3.8'

在此之后，在您的活动中编写代码以检查是否授予了权限。

 public void requestCameraAndStorage() {
    String[] permissions = {Manifest.permission.WRITE_EXTERNAL_STORAGE,Manifest.permission.CAMERA}; // dont forget to add these permissions in manifest file.
    Permissions.check(this, permissions, null, null, new PermissionHandler() {
        @Override
        public void onGranted() {
            // do whatever you want to do.
        }

        @Override
        public void onDenied(Context context, ArrayList<String> deniedPermissions) {
            super.onDenied(context, deniedPermissions);
        }
    });
}

然后根据需要在onCreate或任何onButtonClick内调用此方法。此库非常有效地处理onDenied。

如何检查应用程序是否具有特定权限？

4 个答案: