【下载文档:  ASP.NET C#生成下拉列表树实现代码.txt 】

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ASP.NET C#生成下拉列表树实现代码
效果图: 代码: 复制代码 代码如下: using System.Data; using System.Web.UI.WebControls; ///

/// 根据DataTable生成下拉列表树 ///

public class DropDownListHelp { private string gridline; private DataTable dt; public DropDownListHelp() { // //TODO: 在此处添加构造函数逻辑 // } ///

/// 根据Datatable生成树形下拉菜单 ///

/// /// 上级节点关键字段 /// 上级节点值 /// 本节点关键字段 /// 排序字符串 /// DownList public void createDropDownTree(DataTable datatable, string parentKeyField, string parentKey, string keyField, string textField, string sortString, DropDownList ddl) { dt = datatable; ddl.Items.Add(new ListItem("", "")); addChildItems(parentKeyField, parentKey, keyField, textField, sortString, ddl); } ///

/// 递归生成树节点 ///

/// 上级节点关键字段 /// 上级节点值 /// 本节点关键字段 /// 排序字符串 /// DownList控件 /// private void addChildItems(string parentKeyField, string parentKey, string keyField, string textField, string sortString, DropDownList ddl) { DataView dv = new DataView(dt, parentKeyField + "='" + parentKey + "'", sortString, DataViewRowState.CurrentRows); int a = dv.Count; if (dv.Count == 0) { return; } for (int i = 0; i < a; i++) { gridline = ""; dv.RowFilter = parentKeyField + "='" + parentKey + "'"; dv.Sort = sortString; getTreeLine(parentKeyField, dv[i][parentKeyField].ToString(), keyField, dv[i][keyField].ToString(), sortString); dv.RowFilter = parentKeyField + "='" + parentKey + "'"; dv.Sort = sortString; ddl.Items.Add(new ListItem(gridline + (i == a - 1 ? "┗" : "┣") + dv[i][textField].ToString(), dv[i][keyField].ToString())); addChildItems(parentKeyField, dv[i][keyField].ToString(), keyField, textField, sortString, ddl); } dv.Dispose(); } ///

/// 回溯生成树的连接线 ///

/// 上级节点关键字段 /// 上级节点值 /// 本节点关键字段 /// 本节点值 /// 排序字符串 /// private void getTreeLine(string parentKeyField, string parentKey, string keyField, string nodeKey, string sortString) { //选择父层节点 DataView dv = new DataView(dt, keyField + "='" + parentKey + "'", sortString, DataViewRowState.CurrentRows); if (dv.Count > 0) { //选择父节点同级节点 dv.RowFilter = parentKeyField + "='" + dv[0][parentKeyField].ToString() + "'"; dv.Sort = sortString; for (int j = 0; j < dv.Count; j++) { if (dv[j][keyField].ToString() == parentKey) { if (j == dv.Count - 1) { gridline = "　" + gridline; } else { gridline = "┃" + gridline; } } } getTreeLine(parentKeyField, dv[0][parentKeyField].ToString(), keyField, dv[0][keyField].ToString(), sortString); } dv.Dispose(); } } 调用: 复制代码 代码如下: DropDownListHelp ddlHelper = new DropDownListHelp(); ddlHelper.createDropDownTree(dt, "parentID", "1", "ID","Text", "Text asc", DropDownList1);