iOS 实现半边圆角或部分圆角

正常设置view的圆角

- (UIImageView *)mainImageView {
    if (!_mainImageView) {
        _mainImageView = [[UIImageView alloc] init];
        _mainImageView.layer.cornerRadius = 5.0;
        _mainImageView.layer.masksToBounds = YES;
    }
    return _mainImageView;
}

设置一个或多个

封装了Category方法, 两种方法是一个针对绝对布局一个针对相对布局

UIView+MLCore.h 中的实现

#import 
@interface UIView (LSCore)

#pragma mark - 设置部分圆角
/**
 *  设置部分圆角(绝对布局)
 *
 *  @param corners 需要设置为圆角的角 UIRectCornerTopLeft | UIRectCornerTopRight | UIRectCornerBottomLeft | UIRectCornerBottomRight | UIRectCornerAllCorners
 *  @param radii   需要设置的圆角大小 例如 CGSizeMake(20.0f, 20.0f)
 */
- (void)addRoundedCorners:(UIRectCorner)corners
                withRadii:(CGSize)radii;
/**
 *  设置部分圆角(相对布局)
 *
 *  @param corners 需要设置为圆角的角 UIRectCornerTopLeft | UIRectCornerTopRight | UIRectCornerBottomLeft | UIRectCornerBottomRight | UIRectCornerAllCorners
 *  @param radii   需要设置的圆角大小 例如 CGSizeMake(20.0f, 20.0f)
 *  @param rect    需要设置的圆角view的rect
 */
- (void)addRoundedCorners:(UIRectCorner)corners
                withRadii:(CGSize)radii
                 viewRect:(CGRect)rect;

@end

UIView+LSCore.m 中的实现

#import "UIView+LSCore.h"
@implementation UIView (LSCore)
#pragma mark - 设置部分圆角
/**
 *  设置部分圆角(绝对布局)
 *
 *  @param corners 需要设置为圆角的角 UIRectCornerTopLeft | UIRectCornerTopRight | UIRectCornerBottomLeft | UIRectCornerBottomRight | UIRectCornerAllCorners
 *  @param radii   需要设置的圆角大小 例如 CGSizeMake(20.0f, 20.0f)
 */
- (void)addRoundedCorners:(UIRectCorner)corners
                withRadii:(CGSize)radii {
    
    UIBezierPath* rounded = [UIBezierPath bezierPathWithRoundedRect:self.bounds byRoundingCorners:corners cornerRadii:radii];
    CAShapeLayer* shape = [[CAShapeLayer alloc] init];
    [shape setPath:rounded.CGPath];
    
    self.layer.mask = shape;
}

/**
 *  设置部分圆角(相对布局)
 *
 *  @param corners 需要设置为圆角的角 UIRectCornerTopLeft | UIRectCornerTopRight | UIRectCornerBottomLeft | UIRectCornerBottomRight | UIRectCornerAllCorners
 *  @param radii   需要设置的圆角大小 例如 CGSizeMake(20.0f, 20.0f)
 *  @param rect    需要设置的圆角view的rect
 */
- (void)addRoundedCorners:(UIRectCorner)corners
                withRadii:(CGSize)radii
                 viewRect:(CGRect)rect {
    
    UIBezierPath* rounded = [UIBezierPath bezierPathWithRoundedRect:rect byRoundingCorners:corners cornerRadii:radii];
    CAShapeLayer* shape = [[CAShapeLayer alloc] init];
    [shape setPath:rounded.CGPath];
    
    self.layer.mask = shape;
}
@end

#######示例

- (UIImageView *)blackBGimageView {
    if (!_blackBGimageView) {
        _blackBGimageView = [[UIImageView alloc] init];
        _blackBGimageView.backgroundColor = black_color;
        _blackBGimageView.alpha = 0.7;
        [_blackBGimageView addRoundedCorners:UIRectCornerBottomLeft|UIRectCornerBottomRight  withRadii:CGSizeMake(5.0, 5.0) viewRect:CGRectMake(0, 0, ((SCREEN_WIDTH - 4*10)/2.0), 35)];
    }
    return _blackBGimageView;
}

内容扩展

高性能设置圆角，uiimage封装Category方法

// 等比缩放
- (UIImage *)QS_cropSameImageToSize:(CGSize)size
{
    CGFloat scale =  [UIScreen mainScreen].scale;
    UIGraphicsBeginImageContextWithOptions(size, YES, scale);
    CGSize aspectFitSize = CGSizeZero;
    if (self.size.width != 0 && self.size.height != 0)
    {
        CGFloat rateWidth = size.width / self.size.width;
        CGFloat rateHeight = size.height / self.size.height;
        CGFloat rate = MIN(rateHeight, rateWidth);
        aspectFitSize = CGSizeMake(self.size.width * rate, self.size.height * rate);
    }
    [self drawInRect:CGRectMake(0, 0, aspectFitSize.width, aspectFitSize.height)];
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return image;
}

// 非等比缩放
- (UIImage *)QS_noSameImageToSize:(CGSize)size
{
    CGFloat scale =  [UIScreen mainScreen].scale;
    UIGraphicsBeginImageContextWithOptions(size, YES, scale);
    [self drawInRect:CGRectMake(0, 0, size.width, size.height)];
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return image;
}

//圆角切割
- (UIImage *)QS_getCornerRadius:(CGFloat)cornerRadius
{
    CGFloat scale = [UIScreen mainScreen].scale;
    UIGraphicsBeginImageContextWithOptions(self.size, NO, scale);
    CGContextRef c = UIGraphicsGetCurrentContext();
    CGRect rect = CGRectMake(0, 0, self.size.width, self.size.height);
    UIBezierPath *path = [UIBezierPath bezierPathWithRoundedRect:rect cornerRadius:cornerRadius];
    CGContextAddPath(c, path.CGPath);
    CGContextClip(c);
    [self drawInRect:rect];
    CGContextDrawPath(c, kCGPathFillStroke);
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return image;
}