UIImageView绘制圆形图片

参考网上的资料，自实现了一个UIImageView绘制圆形图片功能。

先看效果：

代码如下：

- (void)buttonAction:(id)sender {

    //方式1，见上图的方式1效果。通过imageview的layer来操作

    UIImageView *imageView1 = [[UIImageViewalloc] initWithImage:[UIImageimageNamed:@"11.png"]];

    imageView1.frame = CGRectMake(60,100, 100, 100);

    imageView1.layer.masksToBounds =YES;

    imageView1.layer.cornerRadius =50;

    [self.view addSubview:imageView1];

    

    //方式2，见上图的方式2效果。对画布裁剪成圆形,然后再将原始图像画出来

    UIImageView *imageView2 = [[UIImageViewalloc] initWithFrame:CGRectMake(60,250, 100,100)];

    UIImage *image2 = [UIImageimageNamed:@"12.png"];

    imageView2.image = [selfcircleImage:image2 withParam:0];

    [self.view addSubview:imageView2];

}

-(UIImage*) circleImage:(UIImage*) image withParam:(CGFloat) inset {

    UIGraphicsBeginImageContext(image.size);

    CGContextRef context =UIGraphicsGetCurrentContext();

    //圆的边框宽度为2，颜色为红色

    CGContextSetLineWidth(context,2);

    CGContextSetStrokeColorWithColor(context, [UIColorredColor].CGColor);

    CGRect rect = CGRectMake(inset, inset, image.size.width - inset *2.0f, image.size.height - inset *2.0f);

    CGContextAddEllipseInRect(context, rect);

    CGContextClip(context);

    //在圆区域内画出image原图

    [image drawInRect:rect];

    CGContextAddEllipseInRect(context, rect);

    CGContextStrokePath(context);

    //生成新的image

    UIImage *newimg = UIGraphicsGetImageFromCurrentImageContext();

    UIGraphicsEndImageContext();

    return newimg;

}