将图像文件写入 sdcard 时出现“Permission Denied”错误

Question

I was using a demo project to acquire and save image into SDcard, it works well. But after creating a new project with the same code, it keeps giving "Permission Denied" error and IO exception.

The xml and gradle files are copied from the demo project and only several activities are deleted, the permissions are stated in the xml file

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

Also dynamically requested in the code

public class PermissionManager {
    private static final int REQUEST_CODE_ASK_PERMISSIONS = 1;
    private static final String[] PERMISSIONS_ARRAYS = new String[] {
            Manifest.permission.READ_EXTERNAL_STORAGE,
            Manifest.permission.WRITE_EXTERNAL_STORAGE};
    private static List<String> permissionsList = new ArrayList<>();
    private PermissionManager() {
    }
    public static void onResume(final Activity activity) {
        boolean isHasPermission = true;
        for (String permission : PERMISSIONS_ARRAYS) {
            if (ContextCompat.checkSelfPermission(activity, permission) != PackageManager.PERMISSION_GRANTED) {
                isHasPermission = false;
                break;
            }
        }
        if (!isHasPermission) {
            for (String permission : PERMISSIONS_ARRAYS) {
                if (ContextCompat.checkSelfPermission(activity, permission) != PackageManager.PERMISSION_GRANTED) {
                    permissionsList.add(permission);
                }
            }
            ActivityCompat.requestPermissions(activity,
                    permissionsList.toArray(new String[permissionsList.size()]), REQUEST_CODE_ASK_PERMISSIONS);
        }
    }

I found there are several questions about this issue but as shown above, the permission request and statement are all set and they work well in the old project, could anyone give some hint?

Answer 1

There's a new feature for devices running on Android 10+ when you are handling media files and probably caused your problem. For Android 10, you can temperarily opt-out the scoped storage by adding this line to the manitest file:

 <application android:requestLegacyExternalStorage="true" ... >