ASP.NET: When and how to dynamically change Gridview's headerText's in code behind?_问答_开发者

I have a gridview with 2 columns. I want to learn coding behind and do NOT wa开发者_开发知识库nt to do this in the aspx file. How do I set the header text for my columns dynamically? At what point do I do so? After the adapter has filled the gridview with data? Right now, I have the header text but it is exactly the same as the datafield name which is last_name and I want to see Last Name in the header field instead. I've tried

GridView1.Columns[0].HeaderText = "Last Name";

but wherever I tried to put it, the compiler complains about index out of range.

Thanks.

aspx code for the gridview:

    <asp:GridView ID="GridView1" runat="server" AllowPaging="True" AllowSorting="True"
                BackColor="White" BorderColor="#DEDFDE" BorderStyle="None" BorderWidth="1px"
                Width="728px" CellPadding="4" ForeColor="Black" GridLines="Vertical" OnPageIndexChanging="GridView1_PageIndexChanging"
                OnSorting="GridView1_Sorting" PageSize="14" OnRowDataBound="GridView1_RowDataBound">
                <AlternatingRowStyle BackColor="White" />
                <FooterStyle BackColor="#CCCC99" />
                <HeaderStyle BackColor="#6B696B" Font-Bold="True" ForeColor="White" />
                <PagerStyle BackColor="#F7F7DE" ForeColor="Black" HorizontalAlign="Right" />
                <RowStyle BackColor="#F7F7DE" />
                <SelectedRowStyle BackColor="#CE5D5A" Font-Bold="True" ForeColor="White" />
                <SortedAscendingCellStyle BackColor="#FBFBF2" />
                <SortedAscendingHeaderStyle BackColor="#848384" />
                <SortedDescendingCellStyle BackColor="#EAEAD3" />
                <SortedDescendingHeaderStyle BackColor="#575357" />
                <PagerSettings Mode="NumericFirstLast" FirstPageText="First" LastPageText="Last"
                    PageButtonCount="5" Position="Bottom" />
            </asp:GridView>

Try putting it in the GridView1.RowDataBound handler. Evaluate e.Row.RowType to determine if it is a header row, then then replace the HeaderText.

protected void GridView1_RowDataBound(object sender, System.Web.UI.WebControls.GridViewRowEventArgs e)
{
    if (e.Row.RowType == DataControlRowType.Header) {
        GridView1.Columns[0].HeaderText = "Last Name";

    }
}

If you are dynamically creating the columns and using sorting, however, you will need to approach it this way to prevent the incidental conversion of the link to sort into plain text:

protected void GridView1_RowDataBound(object sender, System.Web.UI.WebControls.GridViewRowEventArgs e)
{
    if (e.Row.RowType == DataControlRowType.Header) {
        LinkButton HLink = (LinkButton)e.Row.Cells[0].Controls[0];
        HLink.Text = "Last Name";
    }
}

With either, add this attribute to your Gridview in the ASPX:

OnRowDataBound="GridView1_RowDataBound"

Add to Page_Load, but

GridView1.Columns[0].HeaderText = "Last Name";

wouldn't work as it would complain that the column count is 0, hence do this:

protected void grdProd_Load(object sender, EventArgs e)
{
    grdProd.HeaderRow.Cells[0].Text = "Item";
    grdProd.HeaderRow.Cells[1].Text = "Category";
}

I don't think you want to bind text for your header during every row data bind event (1 time for each row) in your Grid!

Just hook on to the Loaded event for the page and then bind the text there like you had it.

 protected void Page_Load(object sender, EventArgs e)
 {
    GridView1.Columns[0].HeaderText = "Last Name";
 }

     <%@ Page Language="C#" AutoEventWireup="true" CodeFile="grdvw8.aspx.cs" Inherits="grdvw8" %>



    <!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 id="Head1" runat="server">

    <title></title>

    </head>

    <body>

    <form id="form1" runat="server">

    <div>

    first header name change To<asp:TextBox ID="txt1" runat="server"></asp:TextBox>

    <br />

    Second header name change To<asp:TextBox ID="txt2" runat="server"></asp:TextBox>

    <br />

    <asp:Button ID="btnChange" Text="Change Header Text" runat="server" onclick="btnChange_Click" />

    <asp:GridView ID="grdvw" runat="server">

    <HeaderStyle Font-Bold="true" ForeColor="Brown" />

    </asp:GridView>

    </div>

    </form>

    </body>

    </html>


/ASPX.CS PAGE/

 using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

using System.Web.UI;

using System.Web.UI.WebControls;

using System.Data;

using System.Data.SqlClient;

using System.Configuration;



public partial class grdvw8 : System.Web.UI.Page

{

    SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["code"].ConnectionString);

    protected void Page_Load(object sender, EventArgs e)

    {

        Bind();

    }



    protected void Bind()

   {

         con.Open();

          SqlCommand cmd=new SqlCommand("select * from gridview",con);

          SqlDataAdapter da=new SqlDataAdapter(cmd);

          DataSet ds=new DataSet();

          da.Fill(ds);

        grdvw.DataSource = ds;

         grdvw.DataBind();



   }



    protected void btnChange_Click(object sender, EventArgs e)

    {

        if (grdvw.Rows.Count > 0)

        {

            grdvw.HeaderRow.Cells[0].Text = txt1.Text;

            grdvw.HeaderRow.Cells[1].Text = txt2.Text;

        }

    }



}