裁剪出环形图片
Posted qigemingnan
tags:
篇首语：本文由小常识网(cha138.com)小编为大家整理，主要介绍了裁剪出环形图片相关的知识，希望对你有一定的参考价值。
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;
float imageSize;
NSLog(@"size==height%f====width%f",size.height,size.width);
if(size.height>= size.width) {
imageSize = size.width;
}else{
imageSize = size.height;
}以上是关于裁剪出环形图片的主要内容，如果未能解决你的问题，请参考以下文章