如何在页面加载时扩展树面板 - EXTJS 4

Question

var tree = Ext.create('Ext.tree.Panel', { 
     store: store, 
     rootVisible: false, 
     //useArrows: true, 
     frame: true, 
     title: 'Vehicle List', 
     region:'west', 
     width: 200, 
     root: { 
     expanded: true 
     }, 
     checked : false, 
     height: 250, 
     dockedItems: [{ 
      xtype: 'toolbar', 
      items: { 
       text: 'Get checked nodes', 
       handler: function(){ 
        var records = tree.getView().getChecked(), 
         names = []; 

        Ext.Array.each(records, function(rec){ 
         names.push(rec.get('MainID')); 
        }); 

        Ext.MessageBox.show({ 
         title: 'Selected Nodes', 
         msg: names.join('<br />'), 
         icon: Ext.MessageBox.INFO 
        }); 
       } 
      } 
     }] 
    }); 

如何让树扩展？我试过

root: { 
     expanded: true 
     } 

但它仍然不起作用。你从服务器返回的每个节点

{ name: 'expanded', type: 'boolean', defaultValue: true, persist: false }, 

或可选择地设置expanded为true：

Answer 1

添加到您的模型。

Answer 2

root: { 
     expanded: true 
     } 

这应该在您的商店的定义。

像下面这样。

var store = Ext.create('Ext.data.TreeStore', { 
    root: { 
     expanded: true, 
     children: [ 
      { text: "a", leaf: true }, 
      { text: "b", expanded: true, children: [ 
       { text: "c", leaf: true }, 
       { text: "d", leaf: true} 
      ] } 
     ] 
    } 
});