封装一：直接封装成了一个方法

/// 边框类型(位移枚举)  
typedef NS_ENUM(NSInteger, UIBorderSideType) {  
    UIBorderSideTypeAll    = 0,  
    UIBorderSideTypeTop    = 1 << 0,  
    UIBorderSideTypeBottom = 1 << 1,  
    UIBorderSideTypeLeft   = 1 << 2,  
    UIBorderSideTypeRight  = 1 << 3,  
};  
  
/** 
 设置view指定位置的边框 
 
 @param originalView   原view 
 @param color          边框颜色 
 @param borderWidth    边框宽度 
 @param borderType     边框类型 例子: UIBorderSideTypeTop|UIBorderSideTypeBottom 
 @return  view 
 */  
- (UIView *)borderForView:(UIView *)originalView color:(UIColor *)color borderWidth:(CGFloat)borderWidth borderType:(UIBorderSideType)borderType {  
      
    if (borderType == UIBorderSideTypeAll) {  
        originalView.layer.borderWidth = borderWidth;  
        originalView.layer.borderColor = color.CGColor;  
        return originalView;  
    }  
      
    /// 线的路径  
    UIBezierPath * bezierPath = [UIBezierPath bezierPath];  
      
    /// 左侧  
    if (borderType & UIBorderSideTypeLeft) {  
        /// 左侧线路径  
        [bezierPath moveToPoint:CGPointMake(0.0f, originalView.frame.size.height)];  
        [bezierPath addLineToPoint:CGPointMake(0.0f, 0.0f)];  
    }  
      
    /// 右侧  
    if (borderType & UIBorderSideTypeRight) {  
        /// 右侧线路径  
        [bezierPath moveToPoint:CGPointMake(originalView.frame.size.width, 0.0f)];  
        [bezierPath addLineToPoint:CGPointMake( originalView.frame.size.width, originalView.frame.size.height)];  
    }  
      
    /// top  
    if (borderType & UIBorderSideTypeTop) {  
        /// top线路径  
        [bezierPath moveToPoint:CGPointMake(0.0f, 0.0f)];  
        [bezierPath addLineToPoint:CGPointMake(originalView.frame.size.width, 0.0f)];  
    }  
      
    /// bottom  
    if (borderType & UIBorderSideTypeBottom) {  
        /// bottom线路径  
        [bezierPath moveToPoint:CGPointMake(0.0f, originalView.frame.size.height)];  
        [bezierPath addLineToPoint:CGPointMake( originalView.frame.size.width, originalView.frame.size.height)];  
    }  
    
    CAShapeLayer * shapeLayer = [CAShapeLayer layer];  
    shapeLayer.strokeColor = color.CGColor;  
    shapeLayer.fillColor  = [UIColor clearColor].CGColor;  
    /// 添加路径  
    shapeLayer.path = bezierPath.CGPath;  
    /// 线宽度  
    shapeLayer.lineWidth = borderWidth;  
      
    [originalView.layer addSublayer:shapeLayer];  
      
    return originalView;  
}  

封装二：封装成了类别.h内容

#import <UIKit/UIKit.h>  
  
typedef NS_OPTIONS(NSUInteger, UIBorderSideType) {  
    UIBorderSideTypeAll  = 0,  
    UIBorderSideTypeTop = 1 << 0,  
    UIBorderSideTypeBottom = 1 << 1,  
    UIBorderSideTypeLeft = 1 << 2,  
    UIBorderSideTypeRight = 1 << 3,  
};  
  
@interface UIView (BorderLine)  
  
- (UIView *)borderForColor:(UIColor *)color borderWidth:(CGFloat)borderWidth borderType:(UIBorderSideType)borderType;  
  
@end 

.m内容

#import "UIView+BorderLine.h"  
  
@implementation UIView (BorderLine)  
  
- (UIView *)borderForColor:(UIColor *)color borderWidth:(CGFloat)borderWidth borderType:(UIBorderSideType)borderType {  
      
    if (borderType == UIBorderSideTypeAll) {  
        self.layer.borderWidth = borderWidth;  
        self.layer.borderColor = color.CGColor;  
        return self;  
    }  
      
      
    /// 左侧  
    if (borderType & UIBorderSideTypeLeft) {  
        /// 左侧线路径  
        [self.layer addSublayer:[self addLineOriginPoint:CGPointMake(0.f, 0.f) toPoint:CGPointMake(0.0f, self.frame.size.height) color:color borderWidth:borderWidth]];  
    }  
      
    /// 右侧  
    if (borderType & UIBorderSideTypeRight) {  
        /// 右侧线路径  
        [self.layer addSublayer:[self addLineOriginPoint:CGPointMake(self.frame.size.width, 0.0f) toPoint:CGPointMake( self.frame.size.width, self.frame.size.height) color:color borderWidth:borderWidth]];  
    }  
      
    /// top  
    if (borderType & UIBorderSideTypeTop) {  
        /// top线路径  
        [self.layer addSublayer:[self addLineOriginPoint:CGPointMake(0.0f, 0.0f) toPoint:CGPointMake(self.frame.size.width, 0.0f) color:color borderWidth:borderWidth]];  
    }  
      
    /// bottom  
    if (borderType & UIBorderSideTypeBottom) {  
        /// bottom线路径  
        [self.layer addSublayer:[self addLineOriginPoint:CGPointMake(0.0f, self.frame.size.height) toPoint:CGPointMake( self.frame.size.width, self.frame.size.height) color:color borderWidth:borderWidth]];  
    }  
      
    return self;  
}  
  
- (CAShapeLayer *)addLineOriginPoint:(CGPoint)p0 toPoint:(CGPoint)p1 color:(UIColor *)color borderWidth:(CGFloat)borderWidth {  
  
    /// 线的路径  
    UIBezierPath * bezierPath = [UIBezierPath bezierPath];  
    [bezierPath moveToPoint:p0];  
    [bezierPath addLineToPoint:p1];  
      
    CAShapeLayer * shapeLayer = [CAShapeLayer layer];  
    shapeLayer.strokeColor = color.CGColor;  
    shapeLayer.fillColor  = [UIColor clearColor].CGColor;  
    /// 添加路径  
    shapeLayer.path = bezierPath.CGPath;  
    /// 线宽度  
    shapeLayer.lineWidth = borderWidth;  
    return shapeLayer;  
}   
@end  

用法：

UIView *testView = [[UIView alloc] initWithFrame:CGRectMake(80.0f, 80.0f, 200.0f, 100.0f)];  
    testView.backgroundColor = [UIColor lightGrayColor];  
    [self.view addSubview:testView];  
    [self borderForView:testView color:[UIColor redColor] borderWidth:1.0f borderType:UIBorderSideTypeTop | UIBorderSideTypeBottom];  

效果：

image

不足之处,边框线过宽的话，交界处会有留白；

ps:注意，需要先把你的view加载在父view上，[self.view addSubview:testView]; 之后再设置边框；否则可能会不起作用的；

转载：http://blog.csdn.net/syg90178aw/article/details/72465473