他のアプリの上に重ねて描画することを許可しても、PackageManager.PERMISSION

このようなコードで、
他のアプリの上に重ねて描画することを許可するボタンを

java
1 if (!Settings.canDrawOverlays(this)) {
2                    Intent intent2 = new Intent(Settings.ACTION_MANAGE_OVERLAY_PERMISSION, Uri.parse("package:" + getPackageName()));
3                    startActivityForResult(intent2, OVERLAY_PERMISSION_REQ_CODE);
4                }

この上のコードで呼び出して、onにして、backボタンで戻っても、

java
1int permissionCheck = ContextCompat.checkSelfPermission(this, Settings.ACTION_MANAGE_OVERLAY_PERMISSION);
2
3                 if (permissionCheck == PackageManager.PERMISSION_GRANTED) {
4                     locationActivity();

この中にはいれません。どうすればいいのでしょうか？

//コード全文です。

java
1public class CheckOverlayActivity extends Activity {
2
3        private final int OVERLAY_PERMISSION_REQ_CODE=20;
4
5        @Override
6        protected void onCreate(Bundle savedInstanceState) {
7            super.onCreate(savedInstanceState);
8            setContentView(R.layout.activity_check_overlay);
9            Log.d("MainActivity", "onCreate()");
10
11            if(Build.VERSION.SDK_INT >= 23){
12                Toast toast = Toast.makeText(this, "１、checkOverlayPermissin()を呼ぶ", Toast.LENGTH_SHORT);
13                toast.show();
14                checkOverlayPermission();
15            }
16            else{
17                locationActivity();
18            }
19        }
20
21        public void checkOverlayPermission() {
22            int permissionCheck = ContextCompat.checkSelfPermission(this, Settings.ACTION_MANAGE_OVERLAY_PERMISSION);
23
24            if (permissionCheck == PackageManager.PERMISSION_GRANTED) {
25                Toast toast = Toast.makeText(this, "すでに許可されてた", Toast.LENGTH_SHORT);
26                toast.show();
27
28                locationActivity();
29            }else{
30                Toast toast = Toast.makeText(this, "２、requestOverlayPermission()を呼ぶ", Toast.LENGTH_SHORT);
31                toast.show();
32                requestOverlayPermission();
33            }
34        }
35
36
37        private void requestOverlayPermission(){
38            Toast toast = Toast.makeText(this, "３、requestOverlayPermission()呼ばれた", Toast.LENGTH_SHORT);
39            toast.show();
40            if (Build.VERSION.SDK_INT < 23) {
41            } else {
42    /* android 6 以上 */
43                if (!Settings.canDrawOverlays(this)) {
44                    Intent intent2 = new Intent(Settings.ACTION_MANAGE_OVERLAY_PERMISSION, Uri.parse("package:" + getPackageName()));
45                    startActivityForResult(intent2, OVERLAY_PERMISSION_REQ_CODE);
46                }
47            }
48        }
49
50
51        // 結果の受け取り
52        @Override
53        protected void onActivityResult(int requestCode, int resultCode, Intent data) {
54
55            Toast toast = Toast.makeText(this, "４、結果の受け取り", Toast.LENGTH_SHORT);
56            toast.show();
57
58
59            //これは、使えない
60            // public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
61            //if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
62            //if (ActivityCompat.checkSelfPermission(this, Settings.ACTION_MANAGE_OVERLAY_PERMISSION) == PackageManager.PERMISSION_GRANTED) {
63
64
65             if(requestCode==OVERLAY_PERMISSION_REQ_CODE){
66
67//                if (ActivityCompat.checkSelfPermission(this, Settings.ACTION_MANAGE_OVERLAY_PERMISSION) == PackageManager.PERMISSION_GRANTED) {
68//                        locationActivity();
69
70                 int permissionCheck = ContextCompat.checkSelfPermission(this, Settings.ACTION_MANAGE_OVERLAY_PERMISSION);
71
72                 if (permissionCheck == PackageManager.PERMISSION_GRANTED) {
73                     locationActivity();
74
75                 }else{
76                    Toast toast1 = Toast.makeText(this, "許可をしないと進めません", Toast.LENGTH_SHORT);
77                    toast1.show();
78                }
79             }
80        }
81
82
83        // Intent でLocation
84        private void locationActivity() {
85            Toast toast = Toast.makeText(this, "５、次の画面へ", Toast.LENGTH_SHORT);
86            toast.show();
87            Intent intent = new Intent(getApplication(), CheckStorageActivity.class);
88            startActivity(intent);
89        }
90    }