iOS 13 修改状态栏背景色

iOS 13之后，苹果禁止KVC直接修改私有属性。以前用KVC修改状态栏背景色也会Crash。
新的解决办法如下。

if (@available(iOS 13.0, *)) {
       UIView *statusBar = [[UIView alloc]initWithFrame:[UIApplication sharedApplication].keyWindow.windowScene.statusBarManager.statusBarFrame] ;
        statusBar.backgroundColor = color;
        [[UIApplication sharedApplication].keyWindow addSubview:statusBar];
    } else {
        // Fallback on earlier versions
        UIView *statusBar = [[[UIApplication sharedApplication] valueForKey:@"statusBarWindow"] valueForKey:@"statusBar"];
           if ([statusBar respondsToSelector:@selector(setBackgroundColor:)]) {
               statusBar.backgroundColor = color;
           }
    }