1、通过image mask来操作,需要添加mask目标图片。
mask方法
- + (UIImage*) maskImage:(UIImage*)image withMask:(UIImage*)mask {
- CGImageRef imgRef = [image CGImage];CGImageRef maskRef = [mask CGImage];
- CGImageRef actualMask = CGImageMaskCreate(CGImageGetWidth(maskRef),CGImageGetHeight(maskRef),
- CGImageGetBitsPerComponent(maskRef),CGImageGetBitsPerPixel(maskRef),
- CGImageGetBytesPerRow(maskRef),CGImageGetDataProvider(maskRef),
- NULL, false);CGImageRef masked = CGImageCreateWithMask(imgRef,
- actualMask);return [UIImage imageWithCGImage:masked];
- }
调整图片大小
- + (UIImage *) resizeImage:(UIImage *)image size:(CGSize)newSize {UIGraphicsBeginImageContext(newSize);
- [image drawInRect:CGRectMake(0, 0, newSize.width, newSize.height)];
- UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();UIGraphicsEndImageContext();
- return newImage;
- }
方法调用/:將原始圖片縮成120x120,這一步視原始圖片大小而定,不一定要做
- UIImage *newImg = [Utils resizeImage:orgImg size:CGSizeMake(120, 120)];
- UIImage *maskImg = [UIImage imageNamed:@"mask.png"];
- // 取得mask的圖片物件
- newImg = [ImageUtils maskImage:newImg withMask:maskImg];
- // 開始做裁切(Clip)圖片
小结:详解iPhone开发应用中Mask用法的内容介绍完了
2、通过imageview的layer来操作
如下代码
- UIImageView
* imageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"oiuyfdsa.png"]]; -
imageView.frame = CGRectMake(20.f, 20.f, 100.f, 100.f); -
imageView.layer.masksToBounds = YES; -
imageView.layer.cornerRadius = 50;
a.这种方法需要添加QuarztCore框架才能操作
b.cornerradus的确定问题
3、能过代码对画布裁剪成圆形–》然后再将原始图像画出来–》
- -(UIImage*)
circleImage:(UIImage*) image withParam:(CGFloat) inset { -
UIGraphicsBeginImageCont ext(image.size); -
CGContextRef context = UIGraphicsGetCurrentCont ext(); -
CGContextSetLineWidth(context, 2); -
CGContextSetStrokeColorW ithColor(context, [UIColor redColor].CGColor); -
CGRect rect = CGRectMake(inset, inset, image.size.width - inset * 2.0f, image.size.height - inset * 2.0f); -
CGContextAddEllipseInRec t(context, rect); -
CGContextClip(context); -
-
[image drawInRect:rect]; -
CGContextAddEllipseInRec t(context, rect); -
CGContextStrokePath(context); -
UIImage *newimg = UIGraphicsGetImageFromCu rrentImageContext(); -
UIGraphicsEndImageContex t(); -
return newimg; - }
上面代码注意 如果裁剪后没有使用 CGContextAddEllipseInRec
CGContextStrokePath(context); 这条代码 就会引起背景为白色时看不出来任务效果。
这里是椭圆操作