if(ContextCompat.checkSelfPermission(MainActivity.this,Mainfest.permission.
                WRITE_EXTERNAL_STORAGE)!= PackageManager.PERMISSION_GRANTED){
            ActivityCompat.requestPermissions(MainActivity.this,new String[]{
                    Mainfest.permission.WRITE_EXTERNAL_STORAGE},1);
        }else {        }
    }
进行权限判断和申请,代码中的Mainfest显示红色,错误提示说Error:(60, 72) 错误: 程序包Mainfest不存在