設置指定邊界圓角

最近項目中需要用到一些視圖的某些邊界設置為圓角，比如指定一個長方形view，需要設置其左邊為圓形，所以就封裝一個類來實現指定邊界的圓角

1，首先創建一個繼承於UIView的分類（由於項目中我需設置一個button的圓角， 所以命名為Btn）

2.在介面文件中設置介面

這裡參數：distance 為需要設置圓角的那個邊界的高度或寬度

#import <UIKit/UIKit.h>

typedef enum {
    ZSSideRoundLeft,
    ZSSideRoundRight,
    ZSSideRoundUp,
    ZSSideRoundDown
} ZSSideRound;

@interface UIView (ZSSideRoundBtn)

- (void)roundSide:(ZSSideRound)side distance:(CGFloat)distance;

@end

3.在.m中實現 （在這裡指定邊界設置為半圓）

#import "UIView+ZSSideRoundBtn.h"

@implementation UIView (ZSSideRoundBtn)

- (void)roundSide:(ZSSideRound)side distance:(CGFloat)distance
{
    UIBezierPath* maskPath;

    if (side == ZSSideRoundLeft)
    {
        maskPath = [UIBezierPath bezierPathWithRoundedRect:self.bounds
                                         byRoundingCorners:(UIRectCornerTopLeft | UIRectCornerBottomLeft)
                                               cornerRadii:CGSizeMake(distance/2, distance/2)];
    }
    else if (side == ZSSideRoundRight)
    {
        maskPath = [UIBezierPath bezierPathWithRoundedRect:self.bounds
                                         byRoundingCorners:(UIRectCornerTopRight | UIRectCornerBottomRight)
                                               cornerRadii:CGSizeMake(distance/2, distance/2)];
    }
    else if (side == ZSSideRoundUp)
    {
        maskPath = [UIBezierPath bezierPathWithRoundedRect:self.bounds
                                         byRoundingCorners:(UIRectCornerTopLeft | UIRectCornerTopRight)
                                               cornerRadii:CGSizeMake(distance/2, distance/2)];
    }
    else
    {
        maskPath = [UIBezierPath bezierPathWithRoundedRect:self.bounds
                                         byRoundingCorners:(UIRectCornerBottomLeft | UIRectCornerBottomRight)
                                               cornerRadii:CGSizeMake(distance/2, distance/2)];
    }

    // 創建形狀圖層,設置它的路徑
    CAShapeLayer* maskLayer = [CAShapeLayer layer];
    maskLayer.frame = self.bounds;
    maskLayer.path = maskPath.CGPath;

    // 新創建的形狀圖層設置為圖像視圖層的面具
    self.layer.mask = maskLayer;

    [self.layer setMasksToBounds:YES];
}
@end

搞定，以後需要設置一些UIView的子類視圖的邊界為半圓時，直接引用就OK