使用Json传值的示例

Ext.onReady(function(){ 
var ds = new Ext.data.Store({ 
    proxy: new Ext.data.HttpProxy({url:'grid.jsp'}), 
    reader: new Ext.data.JsonReader({ 
    totalProperty: 'totalProperty', 
  root: 'root' 
}, [ 
    {name: 'id',mapping:'id'}, 
        {name: 'name',mapping:'name'}, 
        {name: 'descn',mapping:'descn'} 
    ]) 
}); 
ds.on('load',function(){ 
      var size = ds.getCount();//获得数据数量 
      alert(size); 
  }); 
var cm = new Ext.grid.ColumnModel([ 
    {header:'编号',dataIndex:'id'}, 
    {header:'名称',dataIndex:'name'}, 
    {header:'描述',dataIndex:'descn'} 
]); 
var grid = new Ext.grid.GridPanel({ 
    el: 'grid', 
    title:'23sdf32', 
ds: ds, 
    cm: cm, 
    bbar: new Ext.PagingToolbar({ 
        pageSize: 10, 
        store: ds, 
        displayInfo: true,