相对某个控件进行布局

Size widgetSize = Director::getInstance()->getWinSize();
        
        Text* alert = Text::create("Layout", "fonts/Marker Felt.ttf", 30 );
        alert->setColor(Color3B(159, 168, 176));
        alert->setPosition(Point(widgetSize.width / 2.0f,
                                 widgetSize.height / 2.0f - alert->getSize().height * 3.075f));
        
        addChild(alert);
        
        
        Layout* layout = Layout::create();
        layout->setSize(Size(widgetSize.width, widgetSize.height));
       
        //横向排列，这里相似Android里的线性布局
        layout->setLayoutType(LAYOUT_RELATIVE);
        /*以图片为背景*/
        layout->setBackGroundImageScale9Enabled(true);
        layout->setBackGroundImage("green_edit.png");
        
        layout->setPosition(Point(0,0));
        addChild(layout);

        
        ImageView* imageView_Center = ImageView::create("scrollviewbg.png");
        layout->addChild(imageView_Center);
        
        RelativeLayoutParameter* rp_Center = RelativeLayoutParameter::create();
        //给布局參数起名字，以便以后别的对象相对它布局
        rp_Center->setRelativeName("rp_Center");
        rp_Center->setAlign(RELATIVE_CENTER_IN_PARENT);
        imageView_Center->setLayoutParameter(rp_Center);
        
        //above center
        ImageView* imageView_AboveCenter = ImageView::create("switch-mask.png");
        layout->addChild(imageView_AboveCenter);
        
        RelativeLayoutParameter* rp_AboveCenter = RelativeLayoutParameter::create();
        //设置相对哪个对象布局
        rp_AboveCenter->setRelativeToWidgetName("rp_Center");
        rp_AboveCenter->setAlign(RELATIVE_LOCATION_ABOVE_CENTER);
        imageView_AboveCenter->setLayoutParameter(rp_AboveCenter);
        
        
        //below center
        ImageView* imageView_BelowCenter = ImageView::create("switch-mask.png");
        layout->addChild(imageView_BelowCenter);
        
        RelativeLayoutParameter* rp_BelowCenter = RelativeLayoutParameter::create();
        rp_BelowCenter->setRelativeToWidgetName("rp_Center");
        rp_BelowCenter->setAlign(RELATIVE_LOCATION_BELOW_CENTER);
        imageView_BelowCenter->setLayoutParameter(rp_BelowCenter);
        
        
        //left center
        ImageView* imageView_LeftCenter = ImageView::create("switch-mask.png");
        layout->addChild(imageView_LeftCenter);
        
        RelativeLayoutParameter* rp_LeftCenter = RelativeLayoutParameter::create();
        rp_LeftCenter->setRelativeToWidgetName("rp_Center");
        rp_LeftCenter->setAlign(RELATIVE_LOCATION_LEFT_OF_CENTER);
        imageView_LeftCenter->setLayoutParameter(rp_LeftCenter);
        
        
        
        //right center
        ImageView* imageView_RightCenter = ImageView::create("switch-mask.png");
        layout->addChild(imageView_RightCenter);
        
        RelativeLayoutParameter* rp_RightCenter = RelativeLayoutParameter::create();
        rp_RightCenter->setRelativeToWidgetName("rp_Center");
        rp_RightCenter->setAlign(RELATIVE_LOCATION_RIGHT_OF_CENTER);
        imageView_RightCenter->setLayoutParameter(rp_RightCenter);