ASP.NET MVC异步获取和刷新ExtJS6 TreeStore

从数据库获取构造树结构是extjs treepanel的核心技术，常用方法是treestroe里配置proxy，这种方式的root成了一个不受控制的节点。

treestroe的root实际是一个层叠json数据，大部分情况是直接写一些简单数据，但在实际应用中必定是要从数据库读取的。我的方法是先用ext.ajax.request获取root数据形成treestroe。定义一个全局的treestroe名字是mtreestore,用ext.ajax.request获得root数据。treestorerefresh函数与此类似，将mtreestore的root换为新值。treepanel的rootvisible属性必须为true，增加一个节点单击事件显示节点的信息。

var mtreestore = null;
ext.ajax.request({
  async: false,
  url: '/api/basicdata_api/getbasictablestreesource',
  method: 'get',
  success: function (response, options)
  {
   var treeroot = ext.decode(response.responsetext);
   mtreestore = ext.create('ext.data.treestore',
   {
    root: treeroot
   });
  },
  failure: function (response, options)
  {
   //var responsearray = ext.decode(response.responsetext);
   ext.msg.alert('服务器错误', '数据处理错误原因:\n\r' + response.responsetext);
  }
});

function treestorerefresh()
{
 ext.ajax.request({
  async: false,
  url: '/api/basicdata_api/getbasictablestreesource',
  method: 'get',
  success: function (response, options)
  {
   var treeroot = ext.decode(response.responsetext);
   if (mtreestore != null)
   {
    mtreestore.setroot(treeroot);
   }
  },
  failure: function (response, options)
  {
   //var responsearray = ext.decode(response.responsetext);
   ext.msg.alert('服务器错误', '数据处理错误原因:\n\r' + response.responsetext);
  }
 });
}

ext.define('treetoolbarcls', {
 extend: 'ext.toolbar.toolbar',
 padding:'0 0 0 0',
 items: [{
  text: '刷新',
  iconcls: 'refresh',
  handler: treestorerefresh,
  height: 30,
  width: 65
 }]
});

ext.define('u1treecls',
{
 extend: 'ext.tree.panel',
 xtype: 'u1tree_xtype',
 //title: '基础数据字典',
 rootvisible: true,
 width: 300,
 store: mtreestore,
 scrollable: true,
 tbar:ext.create('treetoolbarcls'),
 listeners:
 {
  itemclick: nodeclick
 }
});

function nodeclick(node, record, item, index, e, eopts)
{
 if (typeof (record.data) == "undefined")
 {
  return;
 }
 var message = ext.string.format('level={0}<br/>state={1}', record.data.level, record.data.state);
 ext.msg.alert("节点信息", message);
}

下面是后台c#代码

定义一个treenode类，包含treepanel节点固有的一些属性，也可以任意扩充，利用这个可以自定义许多附加数据，如我在里面定义level表示节点的级别。

 [authorize]
 [routeprefix("api/basicdata_api")]
 public class basicdata_apicontroller : apicontroller
 {
  [route("getbasictablestreesource")]
  public httpresponsemessage getbasictablestreesource(string condition = null)
  {
   list<treenode> lstf = new list<treenode>();
   zydadonet z = zydadonet.instance();
   string s1 = "select tablename,title from basedatatables order by tablename";
   string sqltext = s1;
   datatable dt1;
   string errmes;
   z.sql2dtreadonly(s1, out dt1, null, out errmes);
   treenode tnd;
   foreach (datarow drx in dt1.rows)
   {
    tnd = new treenode
    {
     id = drx["tablename"].tostring(),
     text = drx["title"].tostring(),
     level = 1,
     iconcls = "table_6",
     state = drx["tablename"].tostring() + " ok",
     leaf = true
    };
    lstf.add(tnd);
   }
   treenode root = new treenode
   {
    text = "基础数据字典",
    expanded = false,
    iconcls = "folder_close",
    level = 0,
    state = "rootoftree",
    leaf = true
   };
   if (lstf.count > 0)
   {
    root.expanded = true;
    root.leaf = false;
    root.iconcls = "folder_open";
    root.children = lstf;
   }

   string jsonstr;
   jsonstr = jsonconvert.serializeobject(root);
   httpresponsemessage response = request.createresponse(httpstatuscode.ok, "value");
   response.content = new stringcontent(jsonstr, encoding.getencoding("utf-8"), "application/json");
   response.headers.cachecontrol = new cachecontrolheadervalue()
   {
    maxage = timespan.fromminutes(10)
   };
   return response;
  }
 }

 internal class treenode
 {
  public string id { get; set; }
  public string text { get; set; }
  public string iconcls { get; set; }
  public string state { get; set; }
  public bool leaf { get; set; }
  public int level { get; set; }
  public bool expanded { get; set; }
  public list<treenode> children { get; set; }
 }

在nodeclick函数中断可以监视到更多的信息：

最后的运行效果：

然后更改数据表里的数据，点“刷新”就实现了treepanel节点的刷新。

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。