ios 裁剪出一个圆形的头像,,这样的例子在已经很多了,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:
1:首先将一张图片裁剪成圆形图片,,
/**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;
}
2:用CGContextClearRect 的功能 制作环形图片
- (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;
}
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.
注:将长方形图片变成正方形图片:
-(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;
}
当然这是就用到了UIimage的size的属性了.
CGSize size =yuanlai.size;
floatimageSize;
NSLog(@"size==height%f====width%f",size.height,size.width);
if(size.height>= size.width) {
imageSize = size.width;
}else{
imageSize = size.height;
}
有什么不对的地方,大家都提提意见...分享了一关于:绘图详解的文章:http://m.blog.csdn.net/article/details?id=51251717