授予写入权限，但在执行时被拒绝

Question

我在清单中添加了对外部存储设备的写访问权限，并在我的Android手机中授予了这些权限。如果他们不存在，我甚至会在执行时要求他们。

然而，我总是得到这个例外：

Java语言io。FileNotFoundException:/storage/simulated/03b3d97bd-5186-4506-97dc-9994b7ce0761（权限被拒绝）

你知道为什么吗？

try {

    if (Build.VERSION.SDK_INT >= 23) {
        int permissionCheck = ContextCompat.checkSelfPermission(activity, Manifest.permission.WRITE_EXTERNAL_STORAGE);
        if (permissionCheck != PackageManager.PERMISSION_GRANTED) {
            ActivityCompat.requestPermissions(getActivity(), new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, 1);
        }
    }


    OutputStream output = new FileOutputStream(Environment.getExternalStorageDirectory() + image_uuid);
    byte[] buffer = new byte[1024];
    int bytesRead;
    BitmapDrawable bitmapDrawable = (BitmapDrawable) temp.getDrawable();
    etc. etc. etc.

在清单文件中：

</application>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

Answer 1

在获得权限之前，您在sd卡中写入文件。您必须使用以下代码等待授予权限的结果：

@Override
public void onRequestPermissionsResult(int requestCode,
        String permissions[], int[] grantResults) {
    switch (requestCode) {
        case MY_PERMISSIONS_REQUEST_WRITE_EXTERNAL_STORAGE/*1 in here*/: {
            // If request is cancelled, the result arrays are empty.
            if (grantResults.length > 0
                && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                // permission was granted
                // write file here
            } else {
                // permission denied
            }
            return;
        }

        // other 'case' lines to check for other
        // permissions this app might request.
    }
}

请参见此处