如何在OSX中更改NSWindow标题栏的颜色

NSView用名称子类aMyTitleView并添加以下代码

- (void)drawString:(NSString *)string inRect:(NSRect)rect {
    static NSDictionary *att = nil;
    if (!att) {
        NSMutableParagraphStyle *style = [[NSParagraphStyle defaultParagraphStyle] mutableCopy];
        [style setLineBreakMode:NSLineBreakByTruncatingTail];
        [style setAlignment:NSCenterTextAlignment];
        att = [[NSDictionary alloc] initWithObjectsAndKeys: style, NSParagraphStyleAttributeName,[NSColor whiteColor], NSForegroundColorAttributeName,[NSFont fontWithName:@"Helvetica" size:12], NSFontAttributeName, nil];
        [style release];

    }

    NSRect titlebarRect = NSMakeRect(rect.origin.x+20, rect.origin.y-4, rect.size.width, rect.size.height);


    [string drawInRect:titlebarRect withAttributes:att];
}


- (void)drawRect:(NSRect)dirtyRect
{
    NSRect windowFrame = [NSWindow  frameRectForContentRect:[[[self window] contentView] bounds] styleMask:[[self window] styleMask]];
    NSRect contentBounds = [[[self window] contentView] bounds];

    NSRect titlebarRect = NSMakeRect(0, 0, self.bounds.size.width, windowFrame.size.height - contentBounds.size.height);
    titlebarRect.origin.y = self.bounds.size.height - titlebarRect.size.height;

    NSRect topHalf, bottomHalf;
    NSDivideRect(titlebarRect, &topHalf, &bottomHalf, floor(titlebarRect.size.height / 2.0), NSMaxYEdge);

    NSBezierPath * path = [NSBezierPath bezierPathWithRoundedRect:self.bounds xRadius:4.0 yRadius:4.0];
    [[NSBezierPath bezierPathWithRect:titlebarRect] addClip];



    NSGradient * gradient1 = [[[NSGradient alloc] initWithStartingColor:[NSColor colorWithCalibratedWhite:0.0 alpha:1.0] endingColor:[NSColor colorWithCalibratedWhite:1 alpha:1.0]] autorelease];
    NSGradient * gradient2 = [[[NSGradient alloc] initWithStartingColor:[NSColor colorWithCalibratedWhite:1 alpha:1.0] endingColor:[NSColor colorWithCalibratedWhite:0 alpha:1.0]] autorelease];

  [path addClip];


//    [[NSColor colorWithCalibratedWhite:0.00 alpha:1.0] set];
//   [path fill];


   [gradient1 drawInRect:topHalf angle:270.0];
    [gradient2 drawInRect:bottomHalf angle:270.0];

    [[NSColor blackColor] set];
    NSRectFill(NSMakeRect(0, -4, self.bounds.size.width, 1.0));


    [self drawString:@"My Title" inRect:titlebarRect];


}

在appDelegate中，导入类MyTitleView并添加以下代码

- (void)applicationDidFinishLaunching:(NSNotification *)aNotification
{
    NSRect boundsRect = [[[_window contentView] superview] bounds];
    BlackTitlebarView * titleview = [[BlackTitlebarView alloc] initWithFrame:boundsRect];
    [titleview setAutoresizingMask:(NSViewWidthSizable | NSViewHeightSizable)];

    [[[_window contentView] superview] addSubview:titleview positioned:NSWindowBelow relativeTo:[[[[_window contentView] superview] subviews] objectAtIndex:0]];
}