sizeToFit 和 sizeThatFits 区别
2020-07-11 本文已影响0人
Sharif_su
sizeToFit:
会计算出最优的 size 而且会改变自己的size
UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(10, 10, 0, 0)];
[label setBackgroundColor:[UIColor grayColor]];
[label setFont:[UIFont systemFontOfSize:20]];
label.text = @"宽高测试！！！";
[label sizeToFit];
NSLog(@"width=%.1f height=%.1f ", label.frame.size.width, label.frame.size.height);
[self.view addSubview:label];
输入结果
[17002:605091] width=143.0 height=24.0
sizeThatFits:会计算出最优的 size 但是不会改变 自己的 size
UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(10, 10, 0, 0)];
[label setBackgroundColor:[UIColor grayColor]];
[label setFont:[UIFont systemFontOfSize:20]];
label.text = @"宽高测试！！！";
CGSize sizeThatFits = [label sizeThatFits:CGSizeZero];
NSLog(@"sizeThatFits: width=%.1f height=%.1f", sizeThatFits.width, sizeThatFits.height);
NSLog(@"width=%.1f height=%.1f", label.frame.size.width, label.frame.size.height);
[self.view addSubview:label];
test_su[17073:608773] sizeThatFits: width=143 height=24.0
test_su[17073:608773] width=0.0 height=0.
总结:
sizeToFit:直接改变了这个label的宽和高，使它根据上面字符串的大小变化
sizeThatFits:会计算出最优的 size 但是不会改变 自己的 size
