UIView重写drawRect导致视图不遵守masksToBounds

本文介绍了UIView重写drawRect导致视图不遵守masksToBounds的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述 我试图在自定义视图中覆盖UIView的 drawRect：方法。但是，我的视图的边界半径定义为：I am trying to override the drawRect: method of UIView in my custom view. However, my view has a border radius defined as: sub = [[[NSBundle mainBundle] loadNibNamed:@"ProfileView" owner:self options:nil] objectAtIndex:0]; [self addSubview:sub]; [sub setUserInteractionEnabled:YES]; [self setUserInteractionEnabled:YES]; CALayer *layer = sub.layer; layer.masksToBounds = YES; layer.borderWidth = 5.0; layer.borderColor = [UIColor whiteColor].CGColor; layer.cornerRadius = 30.0;这完美无缺，并在我的视图周围放置了一个带边框半径的漂亮边框（不介意背面的对角线/直白线，它们与此视图无关）：This works perfectly and places a nice border with a border radius around my view (don't mind the diagonal/straight white lines at the back, they have nothing to do with this view): 然而，当我尝试覆盖 drawRect：在我看来，我可以看到黑色背景没有掩盖到边界。我不做任何（目前），这是我的代码：However, when I try to override the drawRect: method in my view, I can see a black background not masking to bounds. I don't do anything (currently), here is my code:-(void)drawRect:(CGRect)rect{ [super drawRect:rect];}结果如下： 我'除了绘制方法之外什么都没改变。如何在保持视图遵循角半径蒙版的同时覆盖绘制方法？这是iOS中的错误还是我错过了什么？I've changed nothing but the draw method. How can I override the draw method while keeping my view obey the corner radius mask? Is this a bug in iOS or am I missing something?推荐答案我不知道完整的答案，但我知道UIView的 drawLayer：inContext：的实现方式不同，具体取决于你是否实现了 drawRect：。也许掩盖/限制边界是其中一种不同的方式。I don't know the full answer, but I do know that UIView's implementation of drawLayer:inContext: works differently depending on whether you have implemented drawRect: or not. Perhaps masking/clipping to bounds is one of those things it does differently.您可以尝试通过多种方式解决问题：You can try solving your issue a number of ways: 让你的背景透明：make your background transparent: layer.backgroundColor = [UIColor clearColor].CGColor; 将自己剪辑到自定义 drawRect：：- (void)drawRect:(CGRect)rect { [[UIBezierPath bezierPathWithRoundedRect:rect cornerRadius:30.0] addClip]; [image drawInRect:rect]; // or whatever} 明确划出角落：carve out the corners explicitly:CGContextBeginPath(c);CGContextAddArc(c, r, r, r, M_PI, 3*M_PI_2, 0);CGContextAddLineToPoint(c, 0, 0);CGContextClosePath(c);CGContextClip(c);[[UIColor grayColor] setFill];UIRectFill(rect); 我偷了这个伟大的最后2条建议来自WWDC 2010的演示： iPhone OS上的高级性能优化（视频列在这个索引页面 - 烦人的，没有直接的链接。）I stole those last 2 suggestions from this great presentation from WWDC 2010: Advanced Performance Optimization on iPhone OS (video listed at this index page -- annoyingly, no direct link). 这篇关于UIView重写drawRect导致视图不遵守masksToBounds的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！