如何在没有问题的情况下将角半径应用于 UIView？

Posted 2023-02-24

【中文标题】如何在没有问题的情况下将角半径应用于 UIView？

【英文标题】：How to apply corner radius to a UIView without issues?

【发布时间】：2013-05-12 03:46:36

【问题描述】：

目前我正在将角半径和阴影应用于滚动视图中的多个 UIView。我注意到添加角半径和阴影会使滚动视图在滚动时变得疯狂。如何应用这些影响而不影响我的表现？

【参考方案1】：

尝试同时设置图层的shadowPath：

view.layer.cornerRadius=6.0f;
view.layer.borderWidth=2.0f;
view.layer.borderColor=[UIColor grayColor].CGColor;
view.layer.shadowColor = [UIColor blackColor].CGColor;
view.layer.shadowOpacity = 0.3f;
view.layer.shadowOffset = CGSizeMake(0, 0.0f);
view.layer.masksToBounds = NO;
UIBezierPath *path = [UIBezierPath bezierPathWithRect:view.bounds];
view.layer.shadowPath = path.CGPath;

【参考方案2】：

+(UIImage *)makeRoundCornerImage : (UIImage*) img : (int) cornerWidth : (int) cornerHeight

    UIImage * newImage = nil;

    if( nil != img)
    
        NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
        int w = img.size.width;
        int h = img.size.height;

        CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
        CGContextRef context = CGBitmapContextCreate(NULL, w, h, 8, 4 * w, colorSpace, kCGImageAlphaPremultipliedFirst);

        CGContextBeginPath(context);
        CGRect rect = CGRectMake(0, 0, img.size.width, img.size.height);
        addRoundedRectToPath(context, rect, cornerWidth, cornerHeight);
        CGContextClosePath(context);
        CGContextClip(context);

        CGContextDrawImage(context, CGRectMake(0, 0, w, h), img.CGImage);

        CGImageRef imageMasked = CGBitmapContextCreateImage(context);
        CGContextRelease(context);
        CGColorSpaceRelease(colorSpace);
        [img release];


        newImage = [[UIImage imageWithCGImage:imageMasked] retain];
        CGImageRelease(imageMasked);

        [pool release];
    

    return newImage;

// 借助这个方法我们可以创建任意PNG文件的圆角

 UIImage *imageFromFile = [UIImage imageNamed:@"FilterFields.png"];
        imageFromFile = [ImageManipulator
makeRoundCornerImage:imageFromFile : 10 : 10];


        [SmallTable setImage:imageFromFile];