自定函数获取datagrid,datalist,rpeater控件中header,footer栏中控件

在论坛上看到很多关于datagrid,gridview,datalist,rpeater提取header,footer中控件的问题,整理了一下.供大家分享
下面我以DataGrid为便进行说明.
footer栏又称页脚栏,在很多时候我们可以在该栏放页码及相当的功能键.但是最后在获得这些控件引用的时候就会有点麻烦,由于footer(页脚),header(页眉)都不在DataGrid.Items属性中,该属性返回的集合只包含数据绑定生成的item,所以必须用其他方法来做.下面是我从csdn和其他地方总结而来的几种方法：
1.在ItemCreated或者ItemDataBound中对其控件进行查找;

if (e.Item.ItemType == ListItemType.Footer)

{

}

2.遍历DataGrid中的所有Item.DataGrid.Controls[0]一般来说为生成的Table.

foreach (DataGridItem item in myGrid.Controls[0].Controls)

{

if(item.ItemType==ListItemType.Footer)

{
//用Item.FindControl查找相应的控件

}

前面两种方法大家都经常用，这里再列出以前在csdn上看到的思归大哥提出的另外两种方法。
3.Table t=(Table)DataGrid.Controls[0];
//如果你有Pager的话，那么你需要这样编码T.Rows[T.Rows.Count-2]去获得Pager
DataGridItem item=(DataGridItem)t.Rows[t.Rows.Count-1];
//该item就是Footer,此时你就可以用FindControl查找了。
下面为一个完整的demo

前台页;

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="SearchHeaderAndFooterControl.aspx.cs"
    Inherits="SearchHeaderAndFooterControl" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title>F</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <asp:DataGrid runat="server" ID="gvUserView" DataSourceID="ldsUserData" ShowFooter="True"
            AllowCustomPaging="True" AllowPaging="True"
            onitemdatabound="gvUserView_ItemDataBound">
            <Columns>
                <asp:TemplateColumn>
                    <HeaderTemplate>
                        <asp:TextBox runat="server" ID="txtHeaderInfo" Text="this is header textbox value!"></asp:TextBox>
                    </HeaderTemplate>
                </asp:TemplateColumn>
                <asp:TemplateColumn>
                    <FooterTemplate>
                        <asp:TextBox runat="server" ID="txtFooterInfo" Text="this is footer textbox value!"></asp:TextBox>
                    </FooterTemplate>
                </asp:TemplateColumn>
            </Columns>
        </asp:DataGrid>
        <asp:LinqDataSource ID="ldsUserData" runat="server" ContextTypeName="DataClassesDataContext"
            TableName="Customers">
        </asp:LinqDataSource>
        <br />
        <asp:Button ID="btnGetFooterControlValue" runat="server" Text="获取footer控件" OnClick="btnGetFooterControlValue_Click" />
        <asp:Button ID="btnGetHeaderControlValue" runat="server"
            Text="获取header控件" onclick="btnGetHeaderControlValue_Click" />
    </div>
    </form>
</body>
</html>

后台页;

using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;

public partial class SearchHeaderAndFooterControl : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {

    }

    protected void btnGetFooterControlValue_Click(object sender, EventArgs e)
    {
        #region 方法1
        //foreach (DataGridItem item in gvUserView.Controls[0].Controls)
        //{

        //    if (item.ItemType == ListItemType.Footer)
        //    {
        //        TextBox txtFooter = item.FindControl("txtFooterInfo") as TextBox;
        //        ShowMessage(txtFooter.Text);
        //        break;

        //    }
        //}
        #endregion

        #region 方法2
        //Table clientTable = gvUserView.Controls[0] as Table;
        //DataGridItem item = (DataGridItem)clientTable.Rows[clientTable.Rows.Count - 2];

        //TextBox txtFooter = item.FindControl("txtFooterInfo") as TextBox;
        //ShowMessage(txtFooter.Text);
        #endregion



    }

    private void ShowMessage(string str)
    {
        string notifyInfo = string.Format("alert('{0}');", str);
        Page.ClientScript.RegisterClientScriptBlock(GetType(), "", notifyInfo, true);
    }

    protected void btnGetHeaderControlValue_Click(object sender, EventArgs e)
    {
        foreach (DataGridItem item in gvUserView.Controls[0].Controls)
        {

            if (item.ItemType == ListItemType.Header)
            {
                TextBox txtHeader = item.FindControl("txtHeaderInfo") as TextBox;
                ShowMessage(txtHeader.Text);
                break;
            }
        }

    }

    protected void gvUserView_ItemDataBound(object sender, DataGridItemEventArgs e)
    {
        if (e.Item.ItemType == ListItemType.Header)
        {
            TextBox txtHeader = e.Item.FindControl("txtHeaderInfo") as TextBox;
            ShowMessage(txtHeader.Text);

        }
        //if (e.Item.ItemType == ListItemType.Footer)
        //{
        //    TextBox txtFooter = e.Item.FindControl("txtFooterInfo") as TextBox;
        //    ShowMessage(txtFooter.Text);

        //}
    }
}

如果控件为GridView，则进行简单变换即可使用

if (e.Row.RowType == DataControlRowType.Header)
        {
            TextBox txtHeader = e.Row.FindControl("txtHeaderInfo") as TextBox;
            ShowMessage(txtHeader.Text);

        }
        //if (e.Row.RowType == DataControlRowType.Footer)
        //{
        //    TextBox txtFooter = e.Item.FindControl("txtFooterInfo") as TextBox;
        //    ShowMessage(txtFooter.Text);

        //}

DataList,Repeater也是同理

//if (e.Item.ItemType == ListItemType.Header)
        //{

        //}
        if (e.Item.ItemType == ListItemType.Footer)
        {
            TextBox txtFooter = e.Item.FindControl("txtFooterInfo") as TextBox;
            //TextBox txtFooter = e.Item.Controls[1] as TextBox;
            ShowMessage(txtFooter.Text);
        }