iOS裁剪出环形图片

EddieDurham 4年前
   <p>ios 裁剪出一个圆形的头像,这样的例子在简书已经很多了,我就不详细的介绍了.今天我想讲的是怎么裁剪出一个环形的图片.废话不多说,见代码。</p>    <p>1:首先将一张图片裁剪成圆形图片,,</p>    <pre>  <code class="language-swift">/**圆形图片裁剪*/  - (UIImage *)wjf_circleImage   {      //利用self生成一张圆形图片      // 1.开启图形上下文      UIGraphicsBeginImageContextWithOptions(self.size,NO,0);      // 2.描述圆形路径      UIBezierPath*path = [UIBezierPathbezierPathWithOvalInRect:CGRectMake(0,0,      self.size.width,self.size.height)];      // 3.设置裁剪区域      [pathaddClip];      // 4.画图      [selfdrawAtPoint:CGPointZero];      // 5.取出图片      UIImage*image =UIGraphicsGetImageFromCurrentImageContext();      // 6.关闭上下文      UIGraphicsEndImageContext();      returnimage;  }</code></pre>    <p>2:用CGContextClearRect 的功能 制作环形图片</p>    <pre>  <code class="language-swift">- (UIImage*)getClearRectImage:(UIImage*)image{      UIGraphicsBeginImageContextWithOptions(image.size,NO,0.0f);      CGContextRefctx =UIGraphicsGetCurrentContext();      //默认绘制的内容尺寸和图片一样大,从某一点开始绘制      [imagedrawAtPoint:CGPointZero];      CGFloatbigRaduis = image.size.width/5;      CGRectcirleRect =CGRectMake(image.size.width/2-bigRaduis,       image.size.height/2-bigRaduis, bigRaduis*2, bigRaduis*2);      //CGContextAddArc(ctx,image.size.width/2-bigRaduis,image.size.height/2-bigRaduis,       bigRaduis, 0.0, 2*M_PI, 0);      CGContextAddEllipseInRect(ctx,cirleRect);      CGContextClip(ctx);      CGContextClearRect(ctx,cirleRect);      UIImage*newImage =UIGraphicsGetImageFromCurrentImageContext();      UIGraphicsEndImageContext();      returnnewImage;  }</code></pre>    <p>如果你的图片是正方形的话,就大功告成了,但是你的图片是长方形呢,不用怕.</p>    <p>注:将长方形图片变成正方形图片:</p>    <pre>  <code class="language-swift">- (UIImage * ) getSquareImage: (UIImage    * ) image RangeCGRect: (CGRect) range    centerBool: (BOOL) centerBool {        /*如若centerBool为Yes则是由中心点取mCGRect范围的图片*/        floatimgWidth = image.size.width;        floatimgHeight = image.size.height;        floatviewWidth = range.size.width;        floatviewHidth = range.size.height;        CGRectrect;        if (centerBool)        rect = CGRectMake((imgWidth - viewWidth) / 2,        (imgHeight - viewHidth) / 2, viewWidth, viewHidth);        else {            if (viewHidth            {                if (imgWidth <= imgHeight) {                    rect = CGRectMake(0, 0, imgWidth, imgWidth * viewHidth / viewWidth);                } else {                    floatwidth = viewWidth * imgHeight / viewHidth;                    floatx = (imgWidth - width) / 2;                    if (x > 0) {                        rect = CGRectMake(x, 0, width, imgHeight);                    } else {                        rect = CGRectMake(0, 0, imgWidth, imgWidth * viewHidth / viewWidth);                    }                }            } else {                if (imgWidth <= imgHeight) {                    floatheight = viewHidth * imgWidth / viewWidth;                    if (height < imgHeight) {                        rect = CGRectMake(0, 0, imgWidth, height);                    } else                    {                        rect = CGRectMake(0, 0, viewWidth * imgHeight / viewHidth, imgHeight);                    }                } else                {                    floatwidth = viewWidth * imgHeight / viewHidth;                    if (width < imgWidth)                    {                        floatx = (imgWidth - width) / 2;                        rect = CGRectMake(x, 0, width, imgHeight);                    } else                    {                        rect = CGRectMake(0, 0, imgWidth, imgHeight);                    }                }            }        }        CGImageRefSquareImageRef =        CGImageCreateWithImageInRect(image.CGImage, rect);        CGRectSquareImageBounds = CGRectMake(0, 0, CGImageGetWidth(SquareImageRef),       CGImageGetHeight(SquareImageRef));        UIGraphicsBeginImageContext(SquareImageBounds.size);        CGContextRefcontext = UIGraphicsGetCurrentContext();        CGContextDrawImage(context, SquareImageBounds, SquareImageRef);        UIImage * SquareImage = [UIImageimageWithCGImage: SquareImageRef];        UIGraphicsEndImageContext();        returnSquareImage;    }</code></pre>    <p>当然这是就用到了UIimage的size的属性了.</p>    <pre>  <code class="language-swift">CGSize size = yuanlai.size;  float imageSize;  NSLog(@"size==height%f====width%f",size.height,size.width);  if(size.height>= size.width) {      imageSize = size.width;  }else{      imageSize = size.height;  }</code></pre>    <p> </p>    <p>来自:http://www.cocoachina.com/ios/20160831/17443.html</p>    <p> </p>