UILabel设置border

label.m

UIView *view = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 320, 35)];
UILabel *label = [[UILabel alloc] initWithFrame:CGRectMake(10, 15, 320, 20)];

CALayer *bottomBorder = [CALayer layer];
bottomBorder.frame = CGRectMake(0, 40, 320, .5);

CALayer *rightBorder = [CALayer layer];
rightBorder.frame = CGRectMake(320, 0, 40, .5);

CALayer *topBorder = [CALayer layer];
topBorder.frame = CGRectMake(0, 0, 320, .5);

[view.layer addSublayer:bottomBorder];
[view.layer addSublayer:topBorder];
[view.layer addSublayer:rightBorder];
[view.layer addSublayer:label];