objective-c - 如何让NSView的背景图片不重复？

Question

我想复制以下CSS代码获得的效果:

background: white url(./img/background.png) no-repeat;

我编写了 NSView 的子类并以这种方式重写 drawRect:

- (void)drawRect:(NSRect)dirtyRect
{
    dirtyRect = [self bounds];

    [[NSColor whiteColor] setFill];
    NSRectFill(dirtyRect);

    [[NSColor colorWithPatternImage:[NSImage imageNamed:@"background.png"]] setFill];
    NSRectFill(dirtyRect);
}

(我为我的英语不好道歉)

Answer 1

看看NSImage class reference 。可以使用 drawInRect:fromRect:operation:fraction: 绘制图像还有 drawAtPoint:fromRect:operation:fraction: .

所以你可以使用这个:

[[NSImage imageNamed:@"background.png"] drawInRect:dirtyRect fromRect:NSZeroRect operation:NSCompositeSourceOver fraction:1]; // Passing NSZeroRect causes the entire image to draw. 

而是这样:

[[NSColor colorWithPatternImage:[NSImage imageNamed:@"background.png"]] setFill];
    NSRectFill(dirtyRect);