iOS13 适配的一些坑

1、在iOS13中 ，UISegmentedControl默认样式变为白底黑字。去掉白底和黑色底框，以及黑色分割线如下：

   if (@available(iOS 13.0, *)) {
           //去掉白底
            [SegmentedControl setSelectedSegmentTintColor:[UIColor clearColor]];
         //去掉底色黑框
            [SegmentedControl setBackgroundImage:[UIImage new] forState:UIControlStateNormal barMetrics:UIBarMetricsDefault];
        //去掉中间黑色分割线
            [SegmentedControl setDividerImage:[UIImage new] forLeftSegmentState:UIControlStateNormal rightSegmentState:UIControlStateNormal barMetrics:UIBarMetricsDefault];
        } else {
            // Fallback on earlier versions
        }

2、statusBar 在iOS13的取法也变了，还会引起崩溃。

- (UIView *)statusBar{
   if (_statusBar == nil){
       if (@available(iOS 13.0, *)) {
           UIWindow * keyWindow =  [ UIApplication sharedApplication ].keyWindow ;
          _statusBar= [[UIView alloc ] initWithFrame:keyWindow.windowScene.statusBarManager.statusBarFrame] ;
           [keyWindow addSubview:_statusBar ] ;
       } else {
           // Fallback on earlier versions
         _statusBar = [[[UIApplication sharedApplication] valueForKey:@"statusBarWindow"] valueForKey:@"statusBar"];
       }
   }
   return _statusBar;
}