#新浪微博样式的ActionSheet 实现此功能的关键是在view里面生成一个UIWindow（该window会自动被加入到已有的window上面），然后设置windowlevel和hidden属性就可以显示或者隐藏。

//懒加载window，新建window之后会被自动添加到已有window上，只要设置windowLevel和hidden属性即可显示
-(UIWindow *)actionWindow{

    if (!_actionWindow) {
        _actionWindow = [[UIWindow alloc]initWithFrame:[UIScreen mainScreen].bounds];
        _actionWindow.windowLevel = UIWindowLevelAlert;
        _actionWindow.backgroundColor = [UIColor colorWithRed:0 green:0 blue:0 alpha:.3];
    }
    return _actionWindow;
}

//显示
-(void)show{
    //设置self初始位置
    self.frame = CGRectMake(0, ZDHEIGHT, ZDWIDTH, ZDHEIGHT);
    
    //添加本身到新建window
    [self.actionWindow addSubview:self];
    
    self.actionWindow.hidden = NO;
    [UIView animateWithDuration:ZDANIMATIONTIME animations:^{
        self.frame = CGRectMake(0, 0, ZDWIDTH, ZDHEIGHT);
    }];
}

-(void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event{
    
    [self dismissFromeSuperView];
    
}

//移除
-(void)dismissFromeSuperView {
    
    [UIView animateWithDuration:ZDANIMATIONTIME animations:^{
        self.frame = CGRectMake(0, ZDHEIGHT, ZDWIDTH, ZDHEIGHT);
        
    } completion:^(BOOL finished) {
        
        [self removeFromSuperview];
        self.actionWindow.hidden = YES;
        self.actionWindow = nil;
        
    }];
}