如何把具有標籤3側邊框

Question

我需要把UIView的一個標誌，只有3個邊界可見或突出顯示如圖所示下面image.How做這在Objective-C的的。 如果例如提供，這將是很好。

Answer 1

- (CALayer *)prefix_addUpperBorder:(UIRectEdge)edge color:(UIColor *)color thickness:(CGFloat)thickness 
{ 
    CALayer *border = [CALayer layer]; 

    switch (edge) { 
     case UIRectEdgeTop: 
      border.frame = CGRectMake(0, 0, CGRectGetWidth(self.frame), thickness); 
      break; 
     case UIRectEdgeBottom: 
      border.frame = CGRectMake(0, CGRectGetHeight(self.frame) - thickness, CGRectGetWidth(self.frame), thickness); 
      break; 
     case UIRectEdgeLeft: 
      border.frame = CGRectMake(0, 0, thickness, CGRectGetHeight(self.frame)); 
      break; 
     case UIRectEdgeRight: 
      border.frame = CGRectMake(CGRectGetWidth(self.frame) - thickness, 0, thickness, CGRectGetHeight(self.frame)); 
      break; 
     default: 
      break; 
    } 

    border.backgroundColor = color.CGColor; 

    [self.layer addSublayer:border]; 

    return border; 
}