动态添加列，关键是实现 ITemplate.InstantiateIn 方法。下面是一个添加 GridView 模板列的例子。
C#代码
<%
...
@ Page Language="C#"
%>
<%
...
@ Import Namespace="System.Data"
%>
DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><script runat="server">...
ICollection CreateDataSource()
...{ DataTable dt = new DataTable(); DataRow dr; dt.Columns.Add(new DataColumn("id", typeof(Int32))); dt.Columns.Add(new DataColumn("text", typeof(string))); for (int i = 0; i < 6; i++) ...{ dr = dt.NewRow(); dr[0] = i; dr[1] = "列表项目 " + i.ToString(); dt.Rows.Add(dr);
} DataView dv = new DataView(dt); return dv; } public class GridViewTemplate : ITemplate ...{ private DataControlRowType templateType; private string columnName; public GridViewTemplate( DataControlRowType type, string colname ) ...{ templateType = type; columnName = colname; } public void InstantiateIn( System.Web.UI.Control container ) ...{ switch (templateType) ...{ case DataControlRowType.Header: Literal lc = new Literal(); lc.Text = columnName; container.Controls.Add(lc); break; case DataControlRowType.DataRow: DropDownList drr = new DropDownList(); drr.ID = "dropdown"; drr.AppendDataBoundItems = true; drr.Items.Add(new ListItem("-----请选择------","")); drr.Items.Add(new ListItem("AA", "a")); drr.Items.Add(new ListItem("BB", "b")); drr.Items.Add(new ListItem("CC", "c")); container.Controls.Add(drr); break; default: break; } } } protected void Page_Load(object sender, EventArgs e) ...{ if (!IsPostBack) ...{ TemplateField customField = new TemplateField(); customField.ShowHeader = true; customField.HeaderTemplate = new GridViewTemplate(DataControlRowType.Header, "动态添加列"); customField.ItemTemplate = new GridViewTemplate(DataControlRowType.DataRow, ""); GridView1.Columns.Add(customField); GridView1.DataSource = CreateDataSource(); GridView1.DataBind(); } } protected void GridView1_RowDataBound( object sender, GridViewRowEventArgs e ) ...{ if (e.Row.RowType == DataControlRowType.DataRow) ...{ //可以在这里访问数据库的其它字段的值，可以设置默认选择项，具体应用，看自己的发挥了。 //下面只是例子，举一反三，不再费话了 DataRowView gv = (DataRowView)e.Row.DataItem; int itemSeleted = Int32.Parse(gv.Row["id"].ToString()) > 3 ? 0 : Int32.Parse(gv.Row["id"].ToString()); DropDownList dr = (DropDownList)e.Row.FindControl("dropdown"); dr.SelectedIndex = itemSeleted; }
}
script><html xmlns="http://www.w3.org/1999/xhtml"><head id="Head1" runat="server"> <title>GridView动态添加模板列的例子
title>
head><body><form id="form1" runat="server"> <asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" OnRowDataBound="GridView1_RowDataBound"> <Columns> <asp:BoundField HeaderText="标题" DataField="text"/>
Columns>
asp:GridView>
form>
body>
html>
