Objective c 在NSCollectionViews子视图上绘制

Objective c 在NSCollectionViews子视图上绘制,objective-c,drawing,nscollectionview,Objective C,Drawing,Nscollectionview,我在NSCollectionView子类中有以下代码: -(void)drawRect:(NSRect)rect { if(!NSEqualRects(highlightBox,NSZeroRect)) { [[NSColor colorWithCalibratedRed:1.0f green:0.2f blue:0.2f alpha:1.0f] set]; NSRectFillUsingOperation(NSInsetRec

我在NSCollectionView子类中有以下代码:

-(void)drawRect:(NSRect)rect {  
    if(!NSEqualRects(highlightBox,NSZeroRect)) {        
        [[NSColor colorWithCalibratedRed:1.0f green:0.2f blue:0.2f alpha:1.0f] set];    
        NSRectFillUsingOperation(NSInsetRect(tempHighlightBox, -1.0, -1.0),NSCompositeSourceOver);
        [[NSColor colorWithCalibratedRed:0.2f green:0.2f blue:1.0f alpha:0.5f] set];
        NSRectFillUsingOperation(tempHighlightBox,NSCompositeSourceOver);
    }
}

NSRect绘制正常,但它位于任何NSCollectionViews子视图的后面,我希望它位于顶部。这可能吗?

首先绘制视图,然后在其上绘制其所有子视图。在
drawRect:
方法中无法绘制子视图。为此,还必须重写子视图的
drawRect:
方法