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。