Android Marshmallow: Changing permissions at run time crashes app

Question

Marshmallow has redesigned getting permissions. So Handled permissions before calling the method which needs permissions and it works fine, but It crashes in the following scenario:

Step 1: Opened app and gave all the necessary permissions

Step 2: Clicked Home button(So the app is in background)

Step 3: Manually changed the permissions in the Settings

Step 4: Launched the app from multitasks, now it crashes because of app context becomes invalid

Observed that app gets created again, don't understand why this happens. Any suggestions to rectify this issue would be welcome!

Answer 1

It's because of additional features added from Marshmallow. You need to request from user at runtime. For this use this class which I have made. Then use it whereever required

public class AppPermission {

    public static boolean isMarshmallowPlusDevice() {
        return Build.VERSION.SDK_INT > Build.VERSION_CODES.LOLLIPOP_MR1;
    }

    @TargetApi(Build.VERSION_CODES.M)
    public static boolean isPermissionRequestRequired(Activity activity, @NonNull String[] permissions, int requestCode) {
        if (isMarshmallowPlusDevice() && permissions.length > 0) {
            List<String> newPermissionList = new ArrayList<>();
            for (String permission : permissions) {
                if (PackageManager.PERMISSION_GRANTED != activity.checkSelfPermission(permission)) {
                    newPermissionList.add(permission);
                }
            }
            if (newPermissionList.size() > 0) {
                activity.requestPermissions(newPermissionList.toArray(new String[newPermissionList.size()]), requestCode);
                return true;
            }
        }
        return false;
    }
}

Then put this code where you require permission from user.

if (!AppPermission.isPermissionRequestRequired(SignInActivity.this, new String[]{"android.permission.GET_ACCOUNTS"},
        REQUEST_APP_PERMISSION)) {
    // Your code if permission available
}

After this, in your Fragment or Activity put this code -

@Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
    super.onRequestPermissionsResult(requestCode, permissions, grantResults);
    switch (requestCode) {
        case REQUEST_APP_PERMISSION:
            for (int i = 0; i < permissions.length; i++) {
                String permission = permissions[i];
                int grantResult = grantResults[i];
                switch (permission) {
                    case "android.permission.GET_ACCOUNTS":
                        if (PackageManager.PERMISSION_GRANTED == grantResult) {
                            // Your code
                        }
                        break;
                }
            }
            break;
    }
}

The above code is for request permission for GET_ACCOUNTS you can change it to whatever required.