如何正确定位CATransformLayer在其上层的位置

Question

我已经在一个名为containerView的UIView上创建了一个跨越整个screen.On的视图，必须添加一个CATransormLayer和一个UIView，它们具有以下维度。

CATransformlayer : doubleSidedLayer  
Height = containerView.frame.size.height  
Width = containerView.frame.size.width  

UIView : stripView
Height = containerView.frame.size.height  
Width = 20;

它们的x位置都是由变量positionX指定的。理论上，DoubleSidedLayer和stripView都必须重叠。但事实并非如此。

下面是代码。

CGRect containerFrame =CGRectMake(0,0,self.view.frame.size.height,self.view.frame.size.width);
NSLog(@"container frame = %f %f %f %f",containerFrame.origin.x,containerFrame.origin.y,containerFrame.size.width,containerFrame.size.height);
UIView *containerView = [[UIView alloc]initWithFrame:containerFrame];
[containerView setBackgroundColor:[UIColor grayColor]];

float positionX = containerFrame.size.width/4;//This is the position where the stripView and doubleSidedLayer must be placed

//Configuration of CATransformLayer.
CGRect doubleLayerFrame = CGRectMake(positionX,0,containerFrame.size.width/2,containerFrame.size.height);
CATransformLayer *doubleSidedLayer  = [CATransformLayer layer];
[doubleSidedLayer setFrame:doubleLayerFrame];

NSLog(@"DoubleSidedLayer frame = %f %f %f %f",doubleSidedLayer.frame.origin.x,doubleSidedLayer.frame.origin.y,doubleSidedLayer.frame.size.width,doubleSidedLayer.frame.size.height);
NSLog(@"DoubleSidedLayer bounds = %f %f %f %f",doubleSidedLayer.bounds.origin.x,doubleSidedLayer.bounds.origin.y,doubleSidedLayer.bounds.size.width,doubleSidedLayer.bounds.size.height);
NSLog(@"Anchor Points = %f %f",doubleSidedLayer.anchorPoint.x, doubleSidedLayer.anchorPoint.y);
NSLog(@"position = %f %f",doubleSidedLayer.position.x,doubleSidedLayer.position.y);

//Configuring top layer
CALayer *topLayer = [[CALayer alloc]init];
[topLayer setFrame:doubleLayerFrame];
[topLayer setContents:(id)[UIImage imageNamed:@"1.png"].CGImage];
[topLayer setZPosition:2];
[topLayer setDoubleSided:NO];

//Adding the layers
[doubleSidedLayer addSublayer:topLayer];
[containerView.layer addSublayer:doubleSidedLayer];

//Adding the stripView
UIView *stripView = [[UIView alloc]initWithFrame:CGRectMake(positionX, 0, 20,containerView.frame.size.height)];
[stripView setBackgroundColor:[UIColor cyanColor]];
[containerView addSubview:stripView];
NSLog(@"Strip frame = %f %f %f %f",stripView.frame.origin.x,stripView.frame.origin.y,stripView.frame.size.width,stripView.frame.size.height);

//Adding the containerView to the main view
[self.view addSubview:containerView];

从日志语句中可以看到doubleSidedLayer和stripView的框架。

doubleSidedLayer frame = 120.000000 0.000000 240.000000 300.000000   
strip frame = 120.000000 0.000000 20.000000 300.000000

但这两者并不是重叠的。这是屏幕截图。

​

注意:我的工作方向是横向。

Answer 1

我想知道是否有更简单的方法来实现你想要的东西。例如，如果我有一些视图，我想要将图像从一个图像“翻转”到另一个图像，我使用类似于以下内容：

[UIView transitionWithView:self.imageView
                  duration:0.5
                   options:UIViewAnimationOptionTransitionFlipFromLeft | UIViewAnimationOptionCurveEaseInOut
                animations:^{
                    if (self.flipped)
                        self.imageView.image = [UIImage imageNamed:@"front.png"];
                    else
                        self.imageView.image = [UIImage imageNamed:@"back.png"];

                    self.flipped = !self.flipped;

                }
                completion:nil];

我是用一个图像视图来做这件事的，但是这个概念对你使用的任何UIView控件都是一样的。如果你有一些容器视图，并且你想在这个animations块中添加/删除或者显示/隐藏控件，你也可以这样做。只需使用容器视图作为transitionWithView的第一个参数。

Answer 2

我可以找出我的错误。topLayer的配置出现问题。这应该在doubleSidedLayer的范围内。所以我把[topLayer setFrame:doubleLayerFrame]改成了[topLayer setFrame:doubleSidedLayer.bounds]。这解决了我的问题。