关于EXTJS的问题，panel里套了一个tabpanel，tabpanel高度200+

Question

说一下我的布局，北，西，中布局，中布局是一个panel，里面套了一个tabpanel，俩都不设高度，ie6下没问题，自动扩展到最大，在IE8里，tabpanel的高度只有200多像素高，怎样让这个tab自动扩展到整个center区域呢？
代码如下：
 var accordion = new Ext.Panel({
                region:'west',
                split:true,
                width: 200,
                layout:'accordion',
                items: [item1, item2, item3, item4, item5]
            });
            
            var northPanel = new Ext.Panel({
                region: 'north',
                layout: "anchor",
                height: 54,
                cls: "docs-header",
                frame: false,
                split: false,
                item: {
                    xtype: "box",
                    el: "header",
                    border: true
                }
            });
            
            var tabs = new Ext.TabPanel({
                resizeTabs:true, 
                minTabWidth: 115,
                tabWidth:135,
                border:false,
                height:window.screen.height-270,////////////////这里不设，IE6就正常，没办法，写死了，凑合能用，但是缩小窗体就不行了。
                enableTabScroll:true,
                defaults: {autoScroll:true},
                plugins: new Ext.ux.TabCloseMenu(),
                items:[{
                    id:'defaultP',
                    title: '主界面',
                    iconCls: 'home',
                    html: '<iframe id="iframe_main" style="width:100%;height:100%" src="../mainpage.aspx" frameborder="0" scrolling="auto"></iframe>',
                    closable:false
                }]
            });
            tabs.activate('defaultP');
            
            
            var center=new Ext.Panel({
                region:'center',
                items:[tabs]
            });
            
            var viewport = new Ext.Viewport({
                layout:'border',
                items:[accordion,northPanel,tabs]
            });

Answer 1

看看ext布局的例子，提供可能的参考：
center Panel 设置layout:'fit'
不行的话layoutConfig:{type:'vbox',align:'stretch'} 然后在tab里加flex:1，这种方法一定行

Answer 2

就算panel中嵌套着tabPanel 两个都设置为autoHeight:true 就不会出问题

Answer 3

怎样让这个tab自动扩展到整个center区域呢？把viewport的layout改为 layout:"border", 把tabpanel改为layout:"fit" 再试试 var center=new Ext.Panel({
  region:'center',
  layout:"fit",
  items:[tabs]
  });