iOS_UIImage_裁切圆形头像

github地址: https://github.com/mancongiOS/UIImage.git

UIImage的Cagetory

UIImage+ImageCircle.h

- (UIImage *)imageClicpCircleWithRect:(CGRect)rect;

UIImage+ImageCircle.m

#import "UIImage+ImageCircle.h"

@interface View : UIView
@property (nonatomic, strong) UIImage * image;
@end

@implementation View

- (void)drawRect:(CGRect)rect {

    CGContextRef contextRef = UIGraphicsGetCurrentContext();
    CGContextSaveGState(contextRef);

    // Ellipse --> 椭圆的
    CGContextAddEllipseInRect(contextRef, CGRectMake(rect.size.width / , rect.size.height / , rect.size.width / , rect.size.height / ));
    CGContextClip(contextRef);
    CGContextFillPath(contextRef);
    [self.image drawAtPoint:CGPointMake(, )];

    CGContextRestoreGState(contextRef);
}
@end

@implementation UIImage (ImageCircle)

- (UIImage *)imageClicpCircleWithRect:(CGRect)rect {

    View * myView = [[View alloc] init];
    myView.image = self;

    UIGraphicsBeginImageContext(rect.size);
    CGContextRef context = UIGraphicsGetCurrentContext();

    myView.frame = CGRectMake(rect.origin.x, rect.origin.y, rect.size.width, rect.size.height);
    myView.backgroundColor = [UIColor orangeColor];
    [myView.layer renderInContext:context];

    UIImage * imageNew = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    return imageNew;
}

@end

使用:

- (UIImageView *)imageView {
    if (_imageView == nil) {
        self.imageView = [[UIImageView alloc] init];
        self.imageView.backgroundColor = [UIColor redColor];

        UIImage * image = [UIImage imageNamed:@"1.jpg"];
        // 裁剪出来一个在原图中心点,半径为四分之一原图宽高最小值的圆.

        CGFloat imageSizeMin = MIN(image.size.width, image.size.height);

        CGFloat circleImageWH = imageSizeMin;
        CGFloat circleImage_x = (image.size.width - circleImageWH) / ;
        CGFloat circleImage_y = (image.size.height - circleImageWH) / ;

        self.imageView.image = [image imageClicpCircleWithRect:CGRectMake(circleImage_x, circleImage_y, circleImageWH, circleImageWH)];

    } return _imageView;
}