ios window上添加悬浮button 记录

一：创建window添加上面。添加在新建window上

（1）.@property (nonatomic, strong) UIWindow *window;

@property (nonatomic, strong) UIButton *flButton;

 //悬浮按钮所处的顶端UIWindow

//    _window = [[UIWindow alloc] initWithFrame:CGRectMake(screenWidth*0.5 - 36, screenHeight - 122, 72, 72)];

//    _window.layer.cornerRadius = 36;

//    _window.layer.masksToBounds = YES;

//    //使得新建window在最顶端

//    _window.windowLevel = UIWindowLevelAlert + 1;

//    _window.backgroundColor = [UIColor clearColor];

//    [_window addSubview:_flButton];

//    //显示window

//    [_window makeKeyAndVisible];

(2).移除window

 [_window resignKeyWindow];

////    _window = nil;

二：获取单例window，然后将button添加上面。移除时让button隐藏。

@property (nonatomic, strong) UIWindow *window;

 _window = [[UIApplication sharedApplication].windows lastObject];

    // 添加到窗口

    [_window addSubview:_flButton];