ASP.NET 2.0 中动态添加 GridView 模板列以及取值的例子

时间：2010-08-25 来源：Jian P

<%...@ 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:
                    TextBox tb = new TextBox();
                    tb.ID = "ItemNum";
                    tb.Width = 50;
                    tb.DataBinding += new   EventHandler(this.OnDataBinding);
                    container.Controls.Add(tb);
                    break;
                default:
                    break;
            }
        }
        public void OnDataBinding(object sender, EventArgs e)
        {
            TextBox l = (TextBox)sender;//TextBox发送绑定请求
            GridViewRow container = (GridViewRow)l.NamingContainer;
            l.Text = ((DataRowView)container.DataItem)["ItemNum"].ToString();//绑定ItemNum字段
        }
    }

  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>

动态添加的TextBox，PostBack之后就没有了，要取得用户在里面输入的值，要用Request.Form[###]

其中的###需要填入的是控件在客户端的name属性

幸好，虽然嵌套在模版列里的TextBox的name是自动生成的，但终归有规律可循：

假设GridView控件的ID是GridView1，动态添加的TextBox控件的ID是MyText，那么：
protected void Button1_Click(object sender, EventArgs e)
{
    for (int i = 0; i < GridView1.Rows.Count; i++)
    {
        string txtName = "GridView1$ctl"+(i+2).ToString().PadLeft(2,'0')+"$MyText";
        if(Request.Form[txtName]!=null)
         {
             Response.Write(Request.Form[txtName] + "<br/>");
         }
    }
}

ASP.NET 2.0 中动态添加 GridView 模板列 以及取值的例子

ASP.NET 2.0 中动态添加 GridView 模板列以及取值的例子