iOS 為ImageView設定圓角
阿新 • • 發佈:2019-01-28
1.最簡單的是直接設定imageVIew的layer的圓角屬性(_img是一個imageVIew)
_img.layer.cornerRadius=_img.frame.size.width/3;// 將圖層的邊框設定為圓角
_img.layer.masksToBounds=YES;// 隱藏邊界
2.為imageVIew的layer層設定圓角背景圖片(可以把image view設定成任何想要的形狀)
CALayer* maskLayer = [CALayer layer]; maskLayer.frame = CGRectMake(0, 0,_imgView3.frame.size.width,_imgView3.frame.size.height); maskLayer.contents = (id)[[UIImage imageNamed:@"headerBg"] CGImage];//為圖層設定背景圖片 [_imgView3.layer setMask:maskLayer];
headerBg圖片為
3.可以把圖片剪下成圓角形狀
4.也可以用的透明圓角矩形覆蓋合成圖片來形成-(id)createRoundedRectImage:(UIImage*)image size:(CGSize)size { // the size of CGContextRef int w = size.width; int h = size.height; UIImage *img = image; CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB(); CGContextRef context = CGBitmapContextCreate(NULL, w, h, 8, 4 * w, colorSpace,kCGImageAlphaPremultipliedFirst); CGRect rect = CGRectMake(0, 0, w, h); CGContextBeginPath(context); addRoundedRectToPath(context, rect, size.width/3, size.height/3); CGContextClosePath(context); CGContextClip(context); CGContextDrawImage(context, CGRectMake(0, 0, w, h), img.CGImage); CGImageRef imageMasked = CGBitmapContextCreateImage(context); CGContextRelease(context); CGColorSpaceRelease(colorSpace); return [UIImage imageWithCGImage:imageMasked]; } static void addRoundedRectToPath(CGContextRef context, CGRect rect, float ovalWidth, float ovalHeight) { float fw, fh; if (ovalWidth == 0 || ovalHeight == 0) { CGContextAddRect(context, rect); return; } CGContextSaveGState(context); CGContextTranslateCTM(context, CGRectGetMinX(rect), CGRectGetMinY(rect)); CGContextScaleCTM(context, ovalWidth, ovalHeight); fw = CGRectGetWidth(rect) / ovalWidth; fh = CGRectGetHeight(rect) / ovalHeight; CGContextMoveToPoint(context, fw, fh/2); // Start at lower right corner CGContextAddArcToPoint(context, fw, fh, fw/2, fh, 1); // Top right corner CGContextAddArcToPoint(context, 0, fh, 0, fh/2, 1); // Top left corner CGContextAddArcToPoint(context, 0, 0, fw/2, 0, 1); // Lower left corner CGContextAddArcToPoint(context, fw, 0, fw, fh/2, 1); // Back to lower right CGContextClosePath(context); CGContextRestoreGState(context); }
- (UIImage*) maskImage:(UIImage *)image withMask:(UIImage *)maskImage { CGImageRef maskRef = maskImage.CGImage; CGImageRef mask = CGImageMaskCreate(CGImageGetWidth(maskRef), CGImageGetHeight(maskRef), CGImageGetBitsPerComponent(maskRef), CGImageGetBitsPerPixel(maskRef), CGImageGetBytesPerRow(maskRef), CGImageGetDataProvider(maskRef), NULL, false); CGImageRef masked = CGImageCreateWithMask([image CGImage], mask); return [UIImage imageWithCGImage:masked]; }
如果是要圓角矩形形狀的圖片,1和3的效果相同。如果退形狀要求高的話2,4的效果要好很多