iOS使用阴影为UILabel添加底部边框

Question

我可以知道如何UILable仅使用阴影添加底部边框？没有顶部,左侧,右侧边框.

这不起作用.这是我尝试过的代码,但它不起作用.

CALayer* layer = [titleLabel layer];
layer.frame = CGRectMake(-1, -1, titleLabel.frame.size.width, 1.0f);
layer.borderWidth=1;
[layer setBorderWidth:2.0f];
[layer setBorderColor:[UIColor blackColor].CGColor];
[layer setShadowOffset:CGSizeMake(-3.0, 3.0)];
[layer setShadowRadius:5.0];
[layer setShadowOpacity:5.0];

Answer 1

以这种方式测试:

UILabel *lbl = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, 200, 50)];

[lbl setText:@"Testo di prova..."];
[lbl setBackgroundColor:[UIColor clearColor]];
[[self view] addSubview:lbl];
[lbl sizeToFit];

CALayer* layer = [lbl layer];

CALayer *bottomBorder = [CALayer layer];
bottomBorder.borderColor = [UIColor darkGrayColor].CGColor;
bottomBorder.borderWidth = 1;
bottomBorder.frame = CGRectMake(-1, layer.frame.size.height-1, layer.frame.size.width, 1);
[bottomBorder setBorderColor:[UIColor blackColor].CGColor];
[layer addSublayer:bottomBorder];

我希望这可以帮助你