下面是我用来导出从here中截取的GridView的类，它可以处理模板列和图像控件（显示替换文本）。
您可能需要查看PrepareControlForExport（）是如何处理一些控件的，也可能需要在PrepareControlForExport（）中添加更多控件的处理，因为它还不完整。

public class ExportGridView
{
    public static void Export(String fileName, GridView gridView)
    {
        HttpContext.Current.Response.Clear();
        HttpContext.Current.Response.AddHeader("content-disposition", String.Format("attachment; filename={0}", fileName));
        HttpContext.Current.Response.ContentType = "application/ms-excel";

        //  Create a table to contain the grid
        Table table = new Table();

        //  include the gridline settings
        table.GridLines = gridView.GridLines;

        //  add the header row to the table
        if (gridView.HeaderRow != null)
        {
            PrepareControlForExport(gridView.HeaderRow);
            table.Rows.Add(gridView.HeaderRow);
        }

        //  add each of the data rows to the table
        foreach (GridViewRow row in gridView.Rows)
        {
            PrepareControlForExport(row);
            table.Rows.Add(row);
        }

        //  add the footer row to the table
        if (gridView.FooterRow != null)
        {
            PrepareControlForExport(gridView.FooterRow);
            table.Rows.Add(gridView.FooterRow);
        }

        using (StringWriter stringWriter = new StringWriter())
        {
            using (HtmlTextWriter htmlWriter = new HtmlTextWriter(stringWriter))
            {
                //  render the table into the htmlwriter
                table.RenderControl(htmlWriter);

                //  render the htmlwriter into the response
                HttpContext.Current.Response.Write(stringWriter.ToString());
                HttpContext.Current.Response.End();
            }
        }
    }

    private static void PrepareControlForExport(Control control)
    {
        for (int i = 0; i < control.Controls.Count; i++)
        {
            Control c = control.Controls[i];

            if (c is LinkButton)
            {
                control.Controls.Remove(c);
                control.Controls.AddAt(i, new LiteralControl((c as LinkButton).Text));
            }
            else if (c is ImageButton)
            {
                control.Controls.Remove(c);
                control.Controls.AddAt(i, new LiteralControl((c as ImageButton).AlternateText));
            }
            else if (c is HyperLink)
            {
                control.Controls.Remove(c);
                control.Controls.AddAt(i, new LiteralControl((c as HyperLink).Text));
            }
            else if (c is Image)
            {
                control.Controls.Remove(c);
                control.Controls.AddAt(i, new LiteralControl((c as Image).AlternateText));
            }
            else if (c is DropDownList)
            {
                control.Controls.Remove(c);
                control.Controls.AddAt(i, new LiteralControl((c as DropDownList).SelectedItem.Text));
            }
            else if (c is CheckBox)
            {
                control.Controls.Remove(c);
                if ((c as CheckBox).Checked)
                {
                    control.Controls.AddAt(i, new LiteralControl("True"));
                }
                else
                {
                    control.Controls.AddAt(i, new LiteralControl("False"));
                }
            }
            else if (c is HiddenField)
            {
                control.Controls.Remove(c);
            }

            if (c.HasControls())
            {
                PrepareControlForExport(c);
            }
        }
    }
}

• 以下是我最初的DataGrid答案，只是为了完整起见...*

您没有在DataGrid上定义任何列，因此它会自动生成这些列，并生成以下HTML（带有excel标题）：

<table cellspacing="0" rules="all" border="1" style="border-collapse:collapse;">
    <tr>
        <td>ID</td><td>FName</td>
    </tr>
    <tr>
        <td>1</td><td>aaa</td>
    </tr>
    <tr>
        <td>2</td><td>bbb</td>
    </tr>
    <tr>
        <td>3</td><td>ccc</td>
    </tr>
</table>

如果向DataGrid添加一些列，则可以获得所需的输出（不要忘记包括dg.AutoGenerateColumns = false）：

Response.AddHeader("content-disposition", "attachment;filename=tets.xls");
Response.Clear();
Response.Charset = "";
Response.ContentType = "application/vnd.ms-excel";

System.IO.StringWriter stringWrite = new System.IO.StringWriter();
System.Web.UI.HtmlTextWriter htmlWrite = new System.Web.UI.HtmlTextWriter(stringWrite);
System.Web.UI.WebControls.DataGrid dg = new System.Web.UI.WebControls.DataGrid();

BoundColumn column;

column = new BoundColumn();
column.DataField = "ID";
column.HeaderText = "Employee ID";
dg.Columns.Add(column);

column = new BoundColumn();
column.DataField = "FName";
column.HeaderText = "First Name";
dg.Columns.Add(column);

dg.AutoGenerateColumns = false;
dg.DataSource = Data.BuildData();
dg.DataBind();
dg.RenderControl(htmlWrite);
Response.Write(stringWrite.ToString());
Response.End();

您还没有在GridView上定义任何列，所以它会自动生成这些列，生成以下HTML（带有excel标题）：

<div>
    <table cellspacing="0" rules="all" border="1" style="border-collapse:collapse;">
        <tr>
            <th scope="col">Employee ID</th><th scope="col">First Name</th>
        </tr>
        <tr>
            <td>1</td>
            <td>aaa</td>
        </tr>
        <tr>
            <td>2</td>
            <td>bbb</td>
        </tr>
        <tr>
            <td>3</td>
            <td>ccc</td>
        </tr>
    </table>
</div>

如果您向GridView中添加一些列，就可以获得所需的输出（不要忘记包含gv.AutoGenerateColumns = false）：

Response.AddHeader("content-disposition", "attachment;filename=tets.xls");
    Response.Clear();
    Response.Charset = "";
    Response.ContentType = "application/vnd.ms-excel";

    System.IO.StringWriter stringWrite = new System.IO.StringWriter();
    System.Web.UI.HtmlTextWriter htmlWrite = new System.Web.UI.HtmlTextWriter(stringWrite);
    System.Web.UI.WebControls.GridView gv = new System.Web.UI.WebControls.GridView();

    BoundField column;

    column = new BoundField();
    column.DataField = "ID";
    column.HeaderText = "Employee ID";
    gv.Columns.Add(column);

    column = new BoundField();
    column.DataField = "FName";
    column.HeaderText = "First Name";
    gv.Columns.Add(column);

    gv.AutoGenerateColumns = false;
    gv.DataSource = Data.BuildData();
    gv.DataBind();
    gv.RenderControl(htmlWrite);
    Response.Write(stringWrite.ToString());
    Response.End();