Question

在我的应用中，我想获得用户读取和写入外部存储上的数据的权限，我将权限标签放入清单中，如下所示。但是在安装应用程序或运行时以及需要读取或写入存储的位置时，不会征得用户的许可，并且无法读写内存，直到我手动进入设置应用程序访问权限并启用对内存的访问。 / p>

我的清单是这个

<script>
  var $star_rating = $('.star-rating .fa');

  var SetRatingStar = function () {
    return $star_rating.each(function () {
      if (parseInt($star_rating.siblings('input.rating-value').val()) >= parseInt($(this).data('rating'))) {
        return $(this).removeClass('fa-star-o').addClass('fa-star');
      } else {
        return $(this).removeClass('fa-star').addClass('fa-star-o');
      }
    });
  };

  $star_rating.on('click', function () {
    $star_rating.siblings('input.rating-value').val($(this).data('rating'));
    return SetRatingStar();
  });

  SetRatingStar();
  $(document).ready(function () {

  });
</script>

Answer 1

在android API> = 23中，您需要在运行时请求权限。看看here

类似这样的东西

        // Here, thisActivity is the current activity
    if (ContextCompat.checkSelfPermission(thisActivity,
            Manifest.permission.WRITE_EXTERNAL_STORAGE)
            != PackageManager.PERMISSION_GRANTED) {

        // Permission is not granted
        // Should we show an explanation?
        if (ActivityCompat.shouldShowRequestPermissionRationale(thisActivity,
                Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
            // Show an explanation to the user *asynchronously* -- don't block
            // this thread waiting for the user's response! After the user
            // sees the explanation, try again to request the permission.
        } else {
            // No explanation needed; request the permission
            ActivityCompat.requestPermissions(thisActivity,
                    new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE},
                    MY_PERMISSIONS_WRITE_EXTERNAL_STORAGE);

            // MY_PERMISSIONS_REQUEST_READ_CONTACTS is an
            // app-defined int constant. The callback method gets the
            // result of the request.
        }
    } else {
        // Permission has already been granted
    }

但是，Ted permission library是一个避免使用此类样板代码的glib。

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

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


    };

    //check all needed permissions together
    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_EXTERNAL_STORAGE, Manifest.permission.WRITE_EXTERNAL_STORAGE)
            .check();

Answer 2

在您的活动中写下这些行，只需在 super.onCreate（...）和 setContentView（...）之前：

super.onCreate(savedInstanceState);

    // Here, thisActivity is the current activity

    if (ContextCompat.checkSelfPermission(this, Manifest.permission.READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
        ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.READ_EXTERNAL_STORAGE}, 1);
    }

    if (ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
        ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, 1);
    }

    if (ContextCompat.checkSelfPermission(this, Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) {
        ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.CAMERA}, 1);
    }
    setContentView(R.layout.activity_main);

现在它应该可以工作了，它为我解决了这个问题！

Answer 3

从android 24及更高版本开始，您需要运行时权限才能访问设备的某些功能，例如麦克风和摄像头，存储设备等。请使用以下代码检查是否具有存储权限访问权限

  private boolean hasStoragePermission(int requestCode) {
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
        if (checkSelfPermission(Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
            requestPermissions(new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, requestCode);
            return false;
        } else {
            return true;
        }
    } else {
        return true;
    }
}

如果允许执行您的操作，它将显示弹出窗口以允许访问

 @Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
    super.onRequestPermissionsResult(requestCode, permissions, grantResults);
    if (grantResults.length > 0
            && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
        if (requestCode == FILE_ATTACHMENT)
            attachFile();

    }
}

Answer 4

棉花糖或更高版本的存储和画廊使用的读写权限

  private void requestPermission() {
  if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
    requestPermissions(new String[] {
   android.Manifest.permission.WRITE_EXTERNAL_STORAGE}, REQUEST_WRITE_PERMISSION);
   } else {
     openFilePicker();
   }
  }

要检查许可结果，请使用以下方法：

 @Override
 public void onRequestPermissionsResult(int requestCode, @NonNull String[] 
 permissions, @NonNull int[] grantResults) {
 super.onRequestPermissionsResult(requestCode, permissions, grantResults);

switch (requestCode) {
    case STORAGE_PERMISSION_REQUEST_CODE:
        if (grantResults.length > 0 && permissions[0].equals(Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
            // check whether storage permission granted or not.
            if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                //do what you want;
            }
        }
        break;
    default:
        break;
}

}

Answer 5

清理该死的项目，如果仍然无法运行，则重新生成并运行。...

在您的活动的onCreate方法中添加此代码。删除应用程序，清理项目，构建并运行。同样不要忘记在清单中添加所需的权限。（对于较低的API级别，该代码是不必要的，但是从23开始，您也需要此代码）

private fun requestPermission() {

    val permissions = arrayOf(Manifest.permission.ACCESS_FINE_LOCATION, Manifest.permission.WRITE_EXTERNAL_STORAGE)
    this.requestPermissions(permissions, 5)
}

读取和写入外部存储权限不起作用

5 个答案: