(1)Ext.FormPanel

f.getForm().submit({
   url:"......",
   params:{   XX:xx .....}
   success: function (c,v,e) {    //e: 触发事件
                  var json=Ext.decode(v.response.responseText);
               },
   failure:function(c,v,e){}
})

Ext.Ajax.request({
    url:"....",
    params:{XX:xx....},
    success: function (v,c) {
                   var json=Ext.decode(v.responseText);
                },
    failure:function(v,c){}
})