<div><asp:DropDownList ID="DropDownList1" runat="server" onselectedindexchanged="DropDownList1_SelectedIndexChanged" AutoPostBack="True"></asp:DropDownList><asp:GridView ID="GridView1" runat="server"></asp:GridView></div>

/// <summary>/// model类里面的两个属性其实是dropdownlist的Name和Value属性。在本例中两个属性都一样。/// </summary>class ToolDataModel{public string Name { get; set; }public string Value { get; set; }}

//将dataTable转换成list的model集合，并去掉list中重复项，用于绑定dropdownlist.private  List<ToolDataModel> DataTableToList(DataTable dt){List<ToolDataModel> modelList = new List<ToolDataModel>();int rowsCount = dt.Rows.Count;if (rowsCount > 0){ToolDataModel model;//遍历为list初始出for (int n = 0; n < rowsCount; n++){model = new ToolDataModel();if (dt.Rows[n]["m__strToolName"] != null && dt.Rows[n]["m__strToolName"].ToString() != ""){model.Name = dt.Rows[n]["m__strToolName"].ToString();}if (dt.Rows[n]["m__strToolName"] != null && dt.Rows[n]["m__strToolName"].ToString() != ""){model.Value = dt.Rows[n]["m__strToolName"].ToString();}modelList.Add(model);}}//去除list中重复项，这是一个很简单的算法，一看就懂了for (int i = 0; i < modelList.Count; i++){for (int j = i + 1; j < modelList.Count; j++){if (modelList[i].Name == modelList[j].Name){modelList.RemoveAt(modelList.LastIndexOf(modelList[i]));}}}return modelList;}

 protected void Page_Load(object sender, EventArgs e){if (!Page.IsPostBack){BindView();}}private void BindView() {GridView1.DataSource = DataTest.BindData();GridView1.DataBind();//将datatable转换成list集合再绑定数据，ToolDataModel是model类List<ToolDataModel> lstItems = DataTableToList(DataTest.BindData().Tables[0]);//本来是想用linq去掉dropdownlist中重复值，如下面代码，但是linq的distinct很坑爹，所以自己写了一个。//var query = (from data in lstItems//            select data).Distinct<ToolDataModel>();DropDownList1.DataSource = lstItems;//这里绑定model类里的两个属性。看出来为什么要设置name和value两个属性了吧。DropDownList1.DataTextField = "Name";DropDownList1.DataValueField = "Value";DropDownList1.DataBind();}protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e){DataView dv = new DataView();dv = DataTest.BindData().Tables[0].DefaultView;//m__strToolName是dataSet的一个属性，用DataView的RowFilter属性筛选datasetdv.RowFilter = "m__strToolName=" + DropDownList1.SelectedValue;GridView1.DataSource = dv;GridView1.DataBind();}