Customerize NSTableHeaderCell and apply it in tableview

Come from: http://stackoverflow.com/questions/4753282/modifying-table-headers-on-mac

首先，子类化NSTableHeaderCell

@interface CNSTableHeaderCell : NSTableHeaderCell {

}

- (void)drawWithFrame:(CGRect)cellFrame
          highlighted:(BOOL)isHighlighted
               inView:(NSView *)view;
@end

@implementation CNSTableHeaderCell

- (void)drawWithFrame:(CGRect)cellFrame
          highlighted:(BOOL)isHighlighted
               inView:(NSView *)view
{
	CGRect cfillRect, cborderRect;
	NSBezierPath *path = [NSBezierPath bezierPath];
	NSPoint ptStart, ptEnd;
	
	//make two new rect from cellFrame
	//for instance,based on the fourth argument of CGRectDivide -- in this case is 1.0
	//cellFrame = (0,0,200,20),cfillRect = (0,0,200,20-1),cborderRect = (0,20-1,200,1)
	CGRectDivide(cellFrame, &cborderRect, &cfillRect, 1.0, CGRectMaxYEdge);
	
	//make NSRect from CGRect, and fill it with any color you like,in this case is blueColor
	NSRect fillRect = NSMakeRect(cfillRect.origin.x, cfillRect.origin.y, cfillRect.size.width, cfillRect.size.height);
	[[NSColor blueColor] set];
	NSRectFill(fillRect);
	
	//set highlight behavior
	if (isHighlighted) 
	{
		[[NSColor colorWithDeviceWhite:0.0 alpha:0.1] set];
		NSRectFillUsingOperation(fillRect, NSCompositeSourceOver);
	}
	
	//set antialias to make text more smoothly
	[[NSGraphicsContext currentContext] setShouldAntialias:YES];
	
	//draw right vertical line for cell
	ptStart.x = fillRect.origin.x + fillRect.size.width - 1;
	ptStart.y = fillRect.origin.y;
	
	ptEnd.x = fillRect.origin.x + fillRect.size.width - 1;
	ptEnd.y = fillRect.origin.y + fillRect.size.height;
	[path moveToPoint:ptStart];
	[path lineToPoint:ptEnd];
	
	//draw cell bottom line
	ptStart.x = cellFrame.origin.x;
	ptStart.y = cellFrame.origin.y + cellFrame.size.height;
	ptEnd.x = cellFrame.origin.x + cellFrame.size.width;
	ptEnd.y = cellFrame.origin.y + cellFrame.size.height;
	[path moveToPoint:ptStart];
	[path lineToPoint:ptEnd];
	
	//draw cell top line
	ptStart.x = fillRect.origin.x;
	ptStart.y = fillRect.origin.y;
	ptEnd.x = fillRect.origin.x + fillRect.size.width;
	ptEnd.y = fillRect.origin.y;
	[path moveToPoint:ptStart];
	[path lineToPoint:ptEnd];
	
	//set line color and show line
	[[NSColor redColor] set];
	[path stroke];
	
	//finally draw interior
	[self drawInteriorWithFrame:fillRect inView:view];
}

//NSCell method
- (void)drawWithFrame:(CGRect)cellFrame inView:(NSView *)view
{
	[self drawWithFrame:cellFrame highlighted:NO inView:view];
}

//NSCell method
- (void)highlight:(BOOL)isHighlighted
        withFrame:(CGRect)cellFrame
           inView:(NSView *)view
{
	[self drawWithFrame:cellFrame highlighted:isHighlighted inView:view];
}

@end

然后，应用到tableview

	NSTableColumn *aColumn = nil;
	NSArray *arrTableColumns = [self tableColumns];
	for (int i = 0;i<[arrTableColumns count];i++)
	{
		aColumn = [arrTableColumns objectAtIndex:i];
		if ([[aColumn headerCell]class] == [NSTableHeaderCell class]) 
		{
			CNSTableHeaderCell *aHeaderCell = [[CNSTableHeaderCell alloc]
											   initTextCell:[[aColumn headerCell] stringValue]];
			[aHeaderCell setFont:[NSFont fontWithName:@"Arial" size:13]];
			[aHeaderCell setTextColor:[NSColor whiteColor]];
			[aColumn setHeaderCell:aHeaderCell];
			[aHeaderCell release];
		}
	}

效果如图：