IOS 将图片转化裁剪为圆形头像

好久没写了过了,继续开写吧.
将图片转化裁剪为圆形的头像

-(UIImage*) imageToHeadView:(UIImage*)image withParam:(CGFloat)inset{
  
  //先获取大小
  CGFloat lengthW = CGImageGetWidth(image.CGImage);
  CGFloat lengthH = CGImageGetHeight(image.CGImage);
  CGFloat cutSzie;
  //判断长宽比,获得最大正方形裁剪值
  if(lengthW>= lengthH){
      cutSzie = lengthH;
  }
  else cutSzie = lengthW;
  //执行裁剪(为正方形)
  CGImageRef sourceImageRef = [image CGImage]; //将UIImage转换成CGImageRef
  CGRect rect = CGRectMake(lengthW/2-cutSzie/2, lengthH/2 - cutSzie/2, cutSzie, cutSzie);  //构建裁剪区
  CGImageRef newImageRef = CGImageCreateWithImageInRect(sourceImageRef, rect);    //按照给定的矩形区域进行剪裁
  UIImage *newImage = [UIImage imageWithCGImage:newImageRef];                     //将CGImageRef转换成UIImage
  //取圆形
  UIGraphicsBeginImageContextWithOptions(newImage.size, NO, 0);
  CGContextRef context = UIGraphicsGetCurrentContext();
  CGContextSetFillColorWithColor(context, [UIColor clearColor].CGColor);
  CGContextFillPath(context);
  CGContextSetLineWidth(context, .5);
  CGContextSetStrokeColorWithColor(context, [UIColor clearColor].CGColor);
  CGRect newrect = CGRectMake(inset, inset, newImage.size.width - inset * 2.0f, newImage.size.height - inset * 2.0f);
  CGContextAddEllipseInRect(context, newrect);
  CGContextClip(context);
  
  [newImage drawInRect:newrect];
  CGContextAddEllipseInRect(context, newrect);
  CGContextStrokePath(context);
  UIImage *circleImg = UIGraphicsGetImageFromCurrentImageContext();
  UIGraphicsEndImageContext();
  return circleImg;
}

原图:

edit_background1.jpg

效果图:

Demo.png

调用:

  UIImage *img = [UIImage imageNamed:@"edit_background1.jpg"];
  img = [self imageToHeadView:img withParam:0];      //封装的方法,从中间裁剪为圆形,后面参数为偏移量

小小白一只,就是这样啦