ASP.NET MVC異步獲取和刷新ExtJS6 TreeStore

從數據庫獲取構造樹結構是ExtJS TreePanel的核心技術，常用方法是TreeStroe裡配置proxy，這種方式的root成了一個不受控制的節點。

TreeStroe的root實際是一個層疊json數據，大部分情況是直接寫一些簡單數據，但在實際應用中必定是要從數據庫讀取的。我的方法是先用Ext.Ajax.request獲取root數據形成TreeStroe。定義一個全局的TreeStroe名字是mTreeStore,用Ext.Ajax.request獲得root數據。TreeStoreRefresh函數與此類似，將mTreeStore的root換為新值。TreePanel的rootVisible屬性必須為true，增加一個節點單擊事件顯示節點的信息。

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('服務器錯誤', '數據處理錯誤原因:\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('服務器錯誤', '數據處理錯誤原因:\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: '基礎數據字典',
 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("節點信息", message);
}

下面是後台C#代碼

定義一個TreeNode類，包含TreePanel節點固有的一些屬性，也可以任意擴充，利用這個可以自定義許多附加數據，如我在裡面定義Level表示節點的級別。

 [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 = "基礎數據字典",
    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函數中斷可以監視到更多的信息：

最後的運行效果：

然後更改數據表裡的數據，點“刷新”就實現了TreePanel節點的刷新。

以上就是本文的全部內容，希望對大家的學習有所幫助，也希望大家多多支持腳本之家。