導出到Excel返回空白Excel電子表格

Question

我有以下代碼將GridView導出到Excel文件中。 從理論上講，此代碼應該毫無麻煩地導出。 但是，它正在導出空白。

public static void Export(string fileName, GridView gv, System.Web.UI.Control parentControl)
    {
        HttpContext.Current.Response.Clear();
        HttpContext.Current.Response.AddHeader("content-disposition", string.Format("attachment; filename=" + fileName + ".xls"));
        HttpContext.Current.Response.ContentType = "application/ms-excel";

        using (StringWriter sw = new StringWriter())
        {
            using (HtmlTextWriter htw = new HtmlTextWriter(sw))
            {
                //  Create a table to contain the grid
                Table table = new Table();

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

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

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

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

                //Control 'Content_ctlDisplayIssues_gvIssues' of type 'GridView' must be placed inside a form tag with runat=server.
                System.Web.UI.HtmlControls.HtmlForm form = new System.Web.UI.HtmlControls.HtmlForm();
                parentControl.Controls.Add(form);
                form.Controls.Add(gv);
                form.RenderControl(htw);

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

    /// <summary>
    /// Replace any of the contained controls with literals
    /// </summary>
    /// <param name="control"></param>
    private static void PrepareControlForExport(Control control)
    {
        for (int i = 0; i < control.Controls.Count; i++)
        {
            Control current = control.Controls[i];
            if (current is LinkButton)
            {
                control.Controls.Remove(current);
                control.Controls.AddAt(i, new LiteralControl((current as LinkButton).Text));
            }
            else if (current is ImageButton)
            {
                control.Controls.Remove(current);
                control.Controls.AddAt(i, new LiteralControl((current as ImageButton).AlternateText));
            }
            else if (current is HyperLink)
            {
                control.Controls.Remove(current);
                control.Controls.AddAt(i, new LiteralControl((current as HyperLink).Text));
            }
            else if (current is DropDownList)
            {
                control.Controls.Remove(current);
                control.Controls.AddAt(i, new LiteralControl((current as DropDownList).SelectedItem.Text));
            }
            else if (current is CheckBox)
            {
                control.Controls.Remove(current);
                control.Controls.AddAt(i, new LiteralControl((current as CheckBox).Checked ? "True" : "False"));
            }
            else if (current is Image)
            {
                control.Controls.Remove(current);
                control.Controls.AddAt(i, new LiteralControl((current as Image).AlternateText));
            }

            if (current.HasControls())
            {
                GridViewExportUtil.PrepareControlForExport(current);
            }
        }
    }
}

我在這里想念什么嗎？

Answer 1

您是否曾經在NotePad中打開Excel文件？ 里面沒有HTML！ 但是，您正在使用HtmlTextWriter將數據流式傳輸到瀏覽器。 我認為那不會起作用。

如果您確實確定要將數據轉換為Excel本機格式，則可以使用Excel interop ，也可以尋找更簡化的第三方轉換工具。

如果你只需要用戶在Excel中打開一個電子表格，但你不關心如何將數據傳輸到瀏覽器，我建議你在流CSV格式的數據，使用像在技術這篇文章 。

Answer 2

大部分代碼是正確的。 這里的問題是HTML Writer無法正確呈現。 John Wu在回答中提到了這一點。 因此，這里的解決方法很簡單：

代替;

//Control 'Content_ctlDisplayIssues_gvIssues' of type 'GridView' must be placed inside a form tag with runat=server.
System.Web.UI.HtmlControls.HtmlForm form = new System.Web.UI.HtmlControls.HtmlForm();
parentControl.Controls.Add(form);
form.Controls.Add(gv);
form.RenderControl(htw);

我用了;

//here the table is rendered into the html writer
table.RenderControl(htw);

同樣重要的是在Web.config文件中添加此代碼

<add key="PageInspector:ServerCodeMappingSupport" value="Disabled" />

這對我來說是無縫的。