无法在 Android Oreo 中创建目录（API 26）

我已经阅读了 Android Oreo 的行为和更改的文档。

我知道为 Android Oreo (API 26) 创建文件目录有不同的过程

Code :

 File mediaStorageDir = null;

    if (Build.VERSION.SDK_INT >= 26) {
        mediaStorageDir = new File(Environment.getExternalStorageDirectory().toString(), "MyDirectory");
        Log.v("HEREEEEE","YES");
    } else {
        mediaStorageDir = new File(Environment.getExternalStorageDirectory().toString()
                + File.separator + "MyDirectory");
    }

    if (!mediaStorageDir.exists()) {
        if (!mediaStorageDir.mkdirs()) {
            Toast.makeText(RecordVideoActivity.this, "Failed to create directory MyDirectory.",
                    Toast.LENGTH_LONG).show();
            return null;
        }
    }

但每次我举杯时无法创建目录 MyDirectory。我能够Log.v("HEREEEEE","YES");也但不知道它没有创建目录。

高级帮助将不胜感激。！

发布 Lollipop 需要征求许可，你可以在这篇文章中寻找答案here https://stackoverflow.com/a/33162451/5164673

public  boolean isStoragePermissionGranted() {
    if (Build.VERSION.SDK_INT >= 23) {
        if (checkSelfPermission(android.Manifest.permission.WRITE_EXTERNAL_STORAGE)
                == PackageManager.PERMISSION_GRANTED) {
            Log.v(TAG,"Permission is granted");
            return true;
        } else {

            Log.v(TAG,"Permission is revoked");
            ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, 1);
            return false;
        }
    }
    else { //permission is automatically granted on sdk<23 upon installation
        Log.v(TAG,"Permission is granted");
        return true;
    }
}

权限结果回调：

@Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
    super.onRequestPermissionsResult(requestCode, permissions, grantResults);
    if(grantResults[0]== PackageManager.PERMISSION_GRANTED){
        Log.v(TAG,"Permission: "+permissions[0]+ "was "+grantResults[0]);
        //Create your Directory here
    }
}