grid高度自适应

var CM_cmdata_Viewport = new Ext.Viewport({
        id : 'CM_cmdata_Viewport',
        name : 'CM_cmdata_Viewport',
        layout : 'border',
        items : [{
            region : 'center',
            layout : 'fit',
            margins : '27 0 0 0',
            border : false,
            items : CM_cmdata_TabPanel,
            listeners :{
                afterrender : autoSetTableGridHeight
            }
        }]
    });
   
    // ÉèÖÃÒ³Ãæ±í¸ñµÄ¸ß¶È
    function autoSetTableGridHeight(){
        var height = CM_cmdata_dbAndFileGrid.getHeight() + 50 + 10;
        var neGridHeight = Ext.getBody().getHeight() - height;
        CM_cmdata_hostAndTableGrid.setHeight(neGridHeight);
        CM_cmdata_syncHostAndTableGrid.setHeight(Ext.getBody().getHeight()-50);
        Ext.getCmp('CM_cmdata_Viewport').doLayout(true, false);
    }