UIImage，石英光滑圆角 [英] UIImage with smooth rounded corners in quartz

问题描述

我只是在UIImage上测试以下代码以圆角：

   - （UIImage *）makeRoundedImage：（UIImage * ）图像半径:(浮点）半径; 
 {
 CALayer * imageLayer = [CALayer图层]; 
 imageLayer.frame = CGRectMake（0,0，image.size.width，image.size.height）; 
 imageLayer.contents =（id）image.CGImage; 
 
 imageLayer.masksToBounds = YES; 
 imageLayer.cornerRadius = radius; 
 
 UIGraphicsBeginImageContext（image.size）; 
 [imageLayer renderInContext：UIGraphicsGetCurrentContext（）]; 
 UIImage * roundedImage = UIGraphicsGetImageFromCurrentImageContext（）; 
 UIGraphicsEndImageContext（）; 
 
返回roundedImage; 
} 
  

除非仔细观察生成的图像，否则我看起来很好。角落不顺畅。如何使角落变得更平滑/更柔和？

编辑：

石英圆角加工图像：

就像你可以看到角落不平滑。

这是UIImageView的cornerRadius的版本更顺畅。

<这是UIImage类别：

/ p>

   - （UIImage *）imageWithRoundedCornersRadius :( float）radius 
 {
 //开始一个新图像将是具有圆角的新图像
 UIGraphicsBeginImageContextWithOptions（self.size，NO，0）; 
 
 //在绘制任何东西之前添加一个剪辑，形状为圆角矩形
 CGRect rect = CGRectMake（0,0，self.size.width，self.size.height）; 
 [[UIBezierPath bezierPathWithRoundedRect：rect cornerRadius：radius] addClip]; 
 
 //画你的形象
 [self drawInRect：rect]; 
 
 //获取图像，此处设置UIImageView图像
 UIImage * roundedImage = UIGraphicsGetImageFromCurrentImageContext（）; 
 
 //让我们忘记我们正在绘制
 UIGraphicsEndImageContext（）; 
 
返回roundedImage; 
} 
  

I am just testing the following code to round corners on UIImage:

- (UIImage *)makeRoundedImage:(UIImage *)image radius:(float)radius;
{
    CALayer *imageLayer = [CALayer layer];
    imageLayer.frame = CGRectMake(0, 0, image.size.width, image.size.height);
    imageLayer.contents = (id) image.CGImage;

    imageLayer.masksToBounds = YES;
    imageLayer.cornerRadius = radius;

    UIGraphicsBeginImageContext(image.size);
    [imageLayer renderInContext:UIGraphicsGetCurrentContext()];
    UIImage *roundedImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();

    return roundedImage;
}

I looks fine unless you look closely to generated image. Corners are not smooth. How can I make corners to be smoother/softer ?

EDIT:

Processed image with rounded corners in quartz:

Like you can see corner is not smooth.

This is version with UIImageView's cornerRadius that is much more smoother.

Where is the catch ?

解决方案

Here is UIImage category:

- (UIImage *) imageWithRoundedCornersRadius: (float) radius
{
    // Begin a new image that will be the new image with the rounded corners
    UIGraphicsBeginImageContextWithOptions(self.size, NO, 0);

    // Add a clip before drawing anything, in the shape of an rounded rect
    CGRect rect = CGRectMake(0, 0, self.size.width, self.size.height);
    [[UIBezierPath bezierPathWithRoundedRect:rect cornerRadius:radius] addClip];

    // Draw your image
    [self drawInRect:rect];

    // Get the image, here setting the UIImageView image
    UIImage *roundedImage = UIGraphicsGetImageFromCurrentImageContext();

    // Lets forget about that we were drawing
    UIGraphicsEndImageContext();

    return roundedImage;
}

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