iOS-iOS15后获取window的方式

windows API_DEPRECATED("Use UIWindowScene.windows on a relevant window scene instead", ios(2.0, 15.0));

目前使用的获取window的方式只支持到iOS15，所以在项目开发的时候担心之后通过该方法拿到的window有问题，研究了下怎么拿新版的window的办法

 if (@available(iOS 15, *)) {
       __block UIScene * _Nonnull tmpSc;
        [[[UIApplication sharedApplication] connectedScenes] enumerateObjectsUsingBlock:^(UIScene * _Nonnull obj, BOOL * _Nonnull stop) {
            if (obj.activationState == UISceneActivationStateForegroundActive) {
                tmpSc = obj;
                *stop = YES;
            }
        }];
        UIWindowScene *curWinSc = (UIWindowScene *)tmpSc;
        [curWinSc.keyWindow addSubview:self.bgView];
    } else {
        [[[[UIApplication sharedApplication] windows] objectAtIndex:0] addSubview:self.bgView];
    }