版权声明:本文为博主原创文章,未经博主允许不得转载。 https://cloud.tencent.com/developer/article/1337870
本篇博客要说一下alpha这个属性。
alpha属性是用来设置视图的透明度的,可如果直接使用alpha属性,并且使用此属性的视图有子视图,那么其子视图的透明度也会跟着受影响。先看代码以及效果图吧:
代码:
UIView * redV = [UIView alloc initWithFrame:CGRectMake(0, 0, 100, 100)];
redV.backgroundColor = UIColor redColor;
redV.alpha = 0.5;
self.view addSubview:redV;
UILabel * lbl = [UILabel alloc initWithFrame:CGRectMake(0, 0, 50, 50)];
lbl.text = @"我";
lbl.textColor = UIColor whiteColor;
lbl.textAlignment = NSTextAlignmentCenter;
lbl.backgroundColor = UIColor blackColor;
redV addSubview:lbl;
效果图:
以上效果图是直接使用alpha属性的效果。
代码:
UIView * redV = [UIView alloc initWithFrame:CGRectMake(0, 0, 100, 100)];
redV.backgroundColor = [UIColor redColor colorWithAlphaComponent:0.5];
// redV.alpha = 0.5;
self.view addSubview:redV;
UILabel * lbl = [UILabel alloc initWithFrame:CGRectMake(0, 0, 50, 50)];
lbl.text = @"我";
lbl.textColor = UIColor whiteColor;
lbl.textAlignment = NSTextAlignmentCenter;
lbl.backgroundColor = UIColor blackColor;
redV addSubview:lbl;
效果图:
看客根据所需要的效果选择相应的代码吧!