View操作 swift

        //创建View
        let view1 =UIView()
        let view2 =UIView(frame: CGRectMake(20,120, 100,100))
        let view3 =UIView(frame: CGRectMake(40,140, 100,100))
        
        //设置view的尺寸
        view1.frame =CGRectMake(0,100, 100,100)
        
        //设置view的背景色
        view1.backgroundColor =UIColor.redColor()
        view2.backgroundColor =UIColor.greenColor()
        view3.backgroundColor = UIColor.blueColor()
        
        //设置view的中心位置,不改变view的大小
        view1.center =CGPointMake(80,200)
    
        //改变view的宽和高，视图原来的中心位置不变
        view1.bounds =CGRectMake(0,0, 40,40);
        
        //设置view的tag值
        view1.tag =1;
        view2.tag =2;
        view3.tag =3;

        //依次添加三个视图(从上到下是：蓝，绿，红)
        self.view.addSubview(view1)
        self.view.addSubview(view2)
        self.view.addSubview(view3)
        
        //把view1（红）移到最上面
        self.view.bringSubviewToFront(view1)
        
        //把view3（蓝）移到最下面
        self.view.sendSubviewToBack(view3)
        
        //交换两个视图的位置
        self.view.exchangeSubviewAtIndex(0, withSubviewAtIndex: 2)
         
        //把一个视图插在某个位置
        self.view.insertSubview(view1, atIndex:2)
        
        //把一个视图插在另一个视图的下面
        self.view.insertSubview(view1, belowSubview: view3)
        
        //把一个视图插在另一个视图的上面
        self.view.insertSubview(view1, aboveSubview: view2)
         
        //已经添加了某个视图
        self.view.didAddSubview(view1)
            
        //将要移除某个视图
        self.view.willRemoveSubview(view1)
        
        //把一个视图从一个父视图上移到另一个父视图上
        self.view.willMoveToSuperview(view3)
            
        //已经移动到了父视图上
        self.view.didMoveToSuperview()
        
        //把一个视图移动到一个窗口上
        self.view.willMoveToWindow(UIApplication.sharedApplication().keyWindow)
        
        //已经移动到了一个窗口上
        self.view.didMoveToWindow()
            
        //subViews中存放的(红，绿，蓝三个视图)
        let subViews :NSArray = NSArray.init(array:self.view.subviews)
        
        //如何找到一个视图,其实此时view4就是view1,view5也是view1
        let view4 = subViews.objectAtIndex(0)as! UIView
        view4.backgroundColor =UIColor.blackColor()
        let view5 =self.view.viewWithTag(1)
        view5?.backgroundColor =UIColor.purpleColor()
        
        //隐藏view1
        view1.hidden =true;
        
        //删除View2
        view2.removeFromSuperview()
        
        //再添加一个视图
        let lastView =UIView()
        lastView.frame =CGRectMake(0,200, 200,200);
        lastView.backgroundColor =UIColor.init(white:0.80, alpha: 1)
        self.view.addSubview(lastView)
        
        //设置view的透明度
        lastView.alpha =0.5

        //设置lastView的圆角角度
        lastView.layer.cornerRadius =10
        //设置边框的的宽度
        lastView.layer.borderWidth =2
        //设置边框的颜色
        lastView.layer.borderColor =UIColor.redColor().CGColor
        //允许剪切
        lastView.clipsToBounds =true