目前我为背景制作了一个标签,并在UILabel上添加了UIButton.它在iOS 7中显示,但在iOS 8中它没有显示.如果我用UIView替换UILabel那么它工作正常.
如果我使用此代码在iOS 8中使用UILabel用于显示UILabel和子视图UIButton
UILabel *downLabel = [[UILabel alloc]init]; downLabel.frame = CGRectMake(0,SCREEN_HEIGHT*0.92,SCREEN_WIDTH,SCREEN_HEIGHT*0.08 ); [downLabel setBackgroundColor:[UIColor colorWithRed:(66/255.f) green:(67/255.f) blue:(63/255.f) alpha:1]]; downLabel.userInteractionEnabled = YES; [self.view addSubview:downLabel]; UIButton *downbtnobj = [[UIButton alloc]initWithFrame:CGRectMake(SCREEN_WIDTH*0.68,downLabel.frame.size.height/10,SCREEN_WIDTH*0.30,downLabel.frame.size.height/1.25)]; UIImage *btndownImage = [UIImage imageNamed:@"img 3.png"]; [downbtnobj setImage:btndownImage forState:UIControlStateNormal]; [downbtnobj addTarget:self action:@selector(bulletInButtonClicked) forControlEvents:UIControlEventTouchUpInside]; [downLabel addSubview:downbtnobj];
现在您只能看到UILabel正在显示,但UILabel上没有显示按钮.
如果我用UIView取代UILabel那么它就显得很完美了.
UIView *downLabel = [[UIView alloc]init]; downLabel.frame = CGRectMake(0,SCREEN_HEIGHT*0.08 ); [downLabel setBackgroundColor:[UIColor colorWithRed:(66/255.f) green:(67/255.f) blue:(63/255.f) alpha:1]]; downLabel.userInteractionEnabled = YES; [self.view addSubview:downLabel]; UIButton *downbtnobj = [[UIButton alloc]initWithFrame:CGRectMake(SCREEN_WIDTH*0.68,downLabel.frame.size.height/1.25)]; UIImage *btndownImage = [UIImage imageNamed:@"img 3.png"]; [downbtnobj setImage:btndownImage forState:UIControlStateNormal]; [downbtnobj addTarget:self action:@selector(bulletInButtonClicked) forControlEvents:UIControlEventTouchUpInside]; [downLabel addSubview:downbtnobj];
在这段代码中你可以看到我只用UIView替换UILabel.现在按钮显示.
可以帮助为什么子视图没有在iOS8中的UILabel上显示
解决方法
目前还不清楚iOS 8中的标签有什么不同,但如果你在标签上调用layoutIfNeeded,则可以解决问题(需要在设置框架后),
UILabel *downLabel = [[UILabel alloc]init]; downLabel.frame = CGRectMake(0,SCREEN_HEIGHT*0.08 ); [downLabel layoutIfNeeded]; [downLabel setBackgroundColor:[UIColor colorWithRed:(66/255.f) green:(67/255.f) blue:(63/255.f) alpha:1]]; downLabel.userInteractionEnabled = YES; [self.view addSubview:downLabel];
编辑后：
我还发现,如果您设置文本(在创建标签后的任何时间),则会出现按钮.
