在NSButtonCell中的圆角NSImage角

问题描述

我有一个NSMatrix与几个NSButtons在它没有文本，但只是图像。其中一个图像是从互联网上下载的，我想在我的OS X应用程序的圆角。

我发现一个答案，几乎是我在看为：但可悲的是它行为疯狂，当我使用it：

  //在我的NSButtonCell子类
  - （void）drawImage：（NSImage *）image withFrame： NSRect）imageFrame inView：（NSView *）controlView 
 {
 // [super drawImage：image withFrame：imageFrame inView：controlView]; 
 
 [NSGraphicsContext saveGraphicsState]; 
 
 NSBezierPath * path = [NSBezierPath bezierPathWithRoundedRect：imageFrame xRadius：5 yRadius：5]; 
 [path addClip]; 
 
 [image drawInRect：imageFrame fromRect：NSZeroRect operation：NSCompositeSourceOver fraction：1.0]; 
 
 [NSGraphicsContext restoreGraphicsState];问题是，如果一个图像是部分透明的（PNG），那么它是一个图像（PNG）。完全破坏，我只在黑色背景上看到几个白色像素。
 
 
 
如果图像不透明，那么它会得到圆角，但旋转180°，我不知道为什么。
 
 
 
有任何建议吗？
解决方案
您需要确保在绘制图像之前正确设置图像的大小，并且应该使用 NSImage 方法 drawInRect：fromRect：operation：fraction：respectFlipped ：hints：以确保图像以正确的方式绘制：
   - （void）drawImage ：（NSImage *）imageFrame：（NSRect）imageFrame inView：（NSView *）controlView 
 {
 // [super drawImage：image withFrame：imageFrame inView：controlView]; 
 
 [NSGraphicsContext saveGraphicsState]; 
 
 NSBezierPath * path = [NSBezierPath bezierPathWithRoundedRect：imageFrame xRadius：5 yRadius：5]; 
 [path addClip]; 
 
 //设置大小
 [image setSize：imageFrame.size]; 
 
 //绘制图像
 [image drawInRect：imageFrame fromRect：NSZeroRect operation：NSCompositeSourceOver fraction：1.0 respectFlipped：YES hints：nil]; 
 
 [NSGraphicsContext restoreGraphicsState]; 
} 
  
如果这样做，图像应该正确绘制，即使它是一个半透明的PNG图片。
 
I have a NSMatrix with a couple of NSButtons in it which have no Text but are only images. One of the images is downloaded from the internet and I would like to have it rounded corners in my OS X application.
I found one answer which nearly is what I was looking for: How to draw a rounded NSImage but sadly it acts crazy when I use it:
// In my NSButtonCell subclass
- (void)drawImage:(NSImage*)image withFrame:(NSRect)imageFrame inView:(NSView*)controlView
{
    // [super drawImage:image withFrame:imageFrame inView:controlView];

    [NSGraphicsContext saveGraphicsState];

    NSBezierPath *path = [NSBezierPath bezierPathWithRoundedRect:imageFrame xRadius:5 yRadius:5];
    [path addClip];

    [image drawInRect:imageFrame fromRect:NSZeroRect operation:NSCompositeSourceOver fraction:1.0];

    [NSGraphicsContext restoreGraphicsState];
}
The problem is that if a image is partly transparent (PNG) then it is completly destroyed and I only see a couple of white pixels on a black background.
And if the image is not transparent then it gets the rounded corners but is rotated 180° and I don't know why.
Any suggestions?
 解决方案 
You need to make sure you set the image's size correctly before drawing it, and you should use the NSImage method drawInRect:fromRect:operation:fraction:respectFlipped:hints: to ensure the image is drawn the correct way up:
- (void)drawImage:(NSImage*)image withFrame:(NSRect)imageFrame inView:(NSView*)controlView
{
    // [super drawImage:image withFrame:imageFrame inView:controlView];

    [NSGraphicsContext saveGraphicsState];

    NSBezierPath *path = [NSBezierPath bezierPathWithRoundedRect:imageFrame xRadius:5 yRadius:5];
    [path addClip];

    //set the size
    [image setSize:imageFrame.size];

    //draw the image
    [image drawInRect:imageFrame fromRect:NSZeroRect operation:NSCompositeSourceOver fraction:1.0 respectFlipped:YES hints:nil];

    [NSGraphicsContext restoreGraphicsState];
}
The image should draw correctly if you do this, even if it's a translucent PNG image.
                        
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