Extjs gridpanel横向滚动条的问题

在gridpanel中加入以下代码：

 

viewConfig : {   
    layout : function() {   
        if (!this.mainBody) {   
            return; // not rendered   
        }   
        var g = this.grid;   
        var c = g.getGridEl();   
        var csize = c.getSize(true);   
        var vw = csize.width;   
        if (!g.hideHeaders && (vw < 20 || csize.height < 20)) { // display:   
            // none?   
            return;   
        }   
        if (g.autoHeight) {   
            if (this.innerHd) {   
                this.innerHd.style.width = (vw) + 'px';   
            }   
        } else {   
            this.el.setSize(csize.width, csize.height);   
            var hdHeight = this.mainHd.getHeight();   
            var vh = csize.height - (hdHeight);   
            this.scroller.setSize(vw, vh);   
            if (this.innerHd) {   
                this.innerHd.style.width = (vw) + 'px';   
            }   
        }   
        if (this.forceFit) {   
            if (this.lastViewWidth != vw) {   
                this.fitColumns(false, false);   
                this.lastViewWidth = vw;   
            }   
        } else {   
            this.autoExpand();   
            this.syncHeaderScroll();   
        }   
        this.onLayout(vw, vh);   
    }   
}