通过此方法可以设置任何控件(UIView的子类)的任意一个方向的圆角

效果如图:

(左上角圆角) (上边两个角圆角) ![Uploading Snip20160116_13_330721.png . . .]

上边两个角是圆角的输入框
下边两个角是圆角的输入框

Snip20160116_15.png

当然,你也可以其他方法实现,比如用一个四个角圆角的view作为背景,然后里面装两个透明的textfield,中间画一条线,但是这种方法稍微有点耗内存,定向圆角是直接对layer进行操作,更加轻量级,所以建议用定向圆角的方法

代码:
如果使用系统的API是办不到的,只能同时设置四个角的圆角,这里我讲介绍一种办法,可以设置定向圆角

使用方法:
//1.导入头文件

 #import "ZHRoundView.h"```
//2.让你的view/label/button...继承自ZHRoundView
//3.只需要一句代码就可搞定

//设置左上角圆角
self.myView.roundType = ZHRoundTypeLeft;
//设置上面两个角是圆角
//self.myView.roundType = ZHRoundTypeTop;

如果想绘制边框

view.borderWidth = 2;
view.borderColor = [UIColor blackColor].CGColor;
view.cornerRadius = 10;

源码:
头文件:ZHRoundView.h

import <UIKit/UIKit.h>

typedef enum{
ZHRoundTypeTop = 0,
ZHRoundTypeLeft,
ZHRoundTypeRight,
ZHRoundTypeBottom,
ZHRoundTypeAll,
ZHRoundTypeNone
}ZHRoundType;

@interface ZHRoundView : UIView
/**

• 圆角类型
  */
  @property(nonatomic,assign)ZHRoundType roundType;

/**

• 边框宽度
  */
  @property (nonatomic ,assign) CGFloat borderWidth;

/**

• 边框颜色
  /
  @property (nonatomic ,assign) CGColorRef borderColor;
  /*
• 圆角的半径
  */
  @property (nonatomic ,assign) CGFloat cornerRadius;
  @end

.m文件
ZHRoundView.m

//
// ZHRoundView.m
// 核心动画
//
// Created by 演员新之助 on 15/12/29.
// Copyright © 2015年 演员新之助. All rights reserved.
//

import "ZHRoundView.h"

@interface ZHRoundView()

@end
@implementation ZHRoundView
/*

// Only override drawRect: if you perform custom drawing.

// An empty implementation adversely affects performance during animation.

• (void)drawRect:(CGRect)rect {

// Drawing code

}

*/

-(instancetype)initWithFrame:(CGRect)frame
{
[self setup];
return [super initWithFrame:frame];
}

-(void)awakeFromNib
{
[self setup];
}

/**

• 初始化
  */
  -(void)setup{
  //默认cornerRadius为10
  _cornerRadius = 10;
  }

/**

• 设置圆角方向(设置边框颜色和宽度应放在此方法之前)

• @param roundType 定向圆角的方向
  */
  -(void)setRoundType:(ZHRoundType)roundType{

  _roundType = roundType;

self.layer.mask = nil;

UIRectCorner   corners;

switch (roundType) {
        
    case ZHRoundTypeLeft:
        
        corners =  UIRectCornerTopLeft;
        
        break;
        
    case ZHRoundTypeRight:
        
        corners = UIRectCornerBottomRight | UIRectCornerTopRight;
        
        break;
        
    case ZHRoundTypeBottom:
        
        corners = UIRectCornerBottomLeft | UIRectCornerBottomRight;
        
        break;
        
    case ZHRoundTypeTop:
        
        corners = UIRectCornerTopRight | UIRectCornerTopLeft;
        
        break;
        
    case ZHRoundTypeNone:
        
        corners = UIRectCornerBottomLeft & UIRectCornerBottomRight;
        
        break;
        
    case ZHRoundTypeAll:
        
        corners = UIRectCornerAllCorners;
        
        break;
        
        
        
    default:
        
        break;
        
}



UIBezierPath *maskPath = [UIBezierPath bezierPathWithRoundedRect:self.bounds byRoundingCorners:corners cornerRadii:CGSizeMake(_cornerRadius, _cornerRadius)];
CAShapeLayer *maskLayer = [CAShapeLayer layer];

maskLayer.frame  = self.bounds;
maskLayer.path   = maskPath.CGPath;
self.layer.mask  = maskLayer;

//绘制边框
CAShapeLayer *strokeLayer = [CAShapeLayer layer];
strokeLayer.path = maskPath.CGPath;
strokeLayer.fillColor = [UIColor clearColor].CGColor;
strokeLayer.strokeColor = _borderColor;
strokeLayer.lineWidth = _borderWidth;


// Transparent view that will contain the stroke layer
UIView *strokeView = [[UIView alloc] initWithFrame:self.bounds];
strokeView.userInteractionEnabled = NO; // in case your container view contains controls
[strokeView.layer addSublayer:strokeLayer];

// configure and add any subviews to the container view

// stroke view goes in last, above all the subviews
[self addSubview:strokeView];

}

@end

PS:源码是在群里大神"恒总"的基础上改进哒╭(╯3╰)╮,他的github地址:https://github.com/iPermanent