具有半透明背景的自定义 NSButton
我正在尝试创建一个具有 50% 不透明黑色背景和白色文本的自定义 NSButton。为此，我对 NSButton 进行了子类化并重载了 DrawRect：
- (void) drawRect:(NSRect)dirtyRect
{
[self setBordered:NO];
//REMED since it has same effect as NSRectFill below
//[[self cell] setBackgroundColor:[NSColor colorWithCalibratedRed:0 green:0 blue:0 alpha:0.2]];
NSColor* backgroundColor = [NSColor colorWithCalibratedWhite:0 alpha:0.3f];
[backgroundColor setFill];
NSRectFill(dirtyRect);
[super drawRect:dirtyRect];
}
白色文本看起来很好，但按钮的背景始终是 100% 不透明。不解释 alpha 值。
有什么想法吗？谢谢！
I'm trying to create a custom NSButton with a 50% opaque black background and white text. To do this I've subclassed NSButton and overloaded DrawRect:
- (void) drawRect:(NSRect)dirtyRect
{
[self setBordered:NO];
//REMED since it has same effect as NSRectFill below
//[[self cell] setBackgroundColor:[NSColor colorWithCalibratedRed:0 green:0 blue:0 alpha:0.2]];
NSColor* backgroundColor = [NSColor colorWithCalibratedWhite:0 alpha:0.3f];
[backgroundColor setFill];
NSRectFill(dirtyRect);
[super drawRect:dirtyRect];
}
The white text appears fine but the button's background is always 100% opaque. The alpha value is not interpreted.
Any ideas? Thanks!
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NSRectFill()的默认操作是 copy 这不是你想要的。将其替换为The default operation of
NSRectFill()is copy which is not what you want. Replace it with我发现的另一个解决方案是保持代码相同，但在 Interface Builder 中为每个按钮打开核心动画层。我对核心动画层了解不够，不知道为什么它会起作用。我之前关闭了 CAL，因为它使我的字体看起来非常锯齿。
Another solution I found was to keep my code the same but turn on the Core Animation Layer for each button in Interface Builder. I don't know enough about Core Animation Layer to know why this worked. I had previously turned CAL off because it was making my fonts look very jagged.