Question

我从GridView导出到Excel文件，我收到上述错误。

  protected void ExportExcelButton_Click(object sender, EventArgs e)
    {
        GridViewExportUtil.Export("Issues.csv", this.gvIssues);
    }

哪个电话：

 public class GridViewExportUtil
{
    public static void Export(string fileName, GridView gv, HashSet<string> selectedRows)
    {
    public static void Export(string fileName, GridView gv)
    {
        Table excelTable = new Table();
        excelTable.GridLines = GridLines.Both;


        excelTable.Rows.Add(gv.HeaderRow);
        foreach (GridViewRow gvRow in gv.Rows)
        {
            excelTable.Rows.Add(gvRow);

        }

        StringWriter wrt = new StringWriter();
        HtmlTextWriter htw = new HtmlTextWriter(wrt);

        System.Web.UI.HtmlControls.HtmlForm form = new System.Web.UI.HtmlControls.HtmlForm();
        Controls.Add(form); // here is where the error is found
        form.Controls.Add(gv);
        form.RenderControl(htw);

        HttpContext.Current.Response.Clear();
        HttpContext.Current.Response.AddHeader("content-disposition", "attachment;filename=" + fileName + DateTime.Today + ".xls");
        HttpContext.Current.Response.ContentType = "application/ms-excel";

        HttpContext.Current.Response.Write(wrt.ToString());
        HttpContext.Current.Response.End();
    }
}

这段代码：

 System.Web.UI.HtmlControls.HtmlForm form = new System.Web.UI.HtmlControls.HtmlForm();
        Controls.Add(form); // here is where the error is found
        form.Controls.Add(gv);
        form.RenderControl(htw);

投入试图解决错误：Control 'cbSelectAll_0' of type 'CheckBox' must be placed inside a form tag with runat=server.

以下也没有帮助：VerifyRenderingInServerForm(Control)：找不到合适的方法来覆盖

Answer 1

此代码假定它作为Page方法的一部分执行。有Controls是有意义的，因为Page.Controls指的是页面上的控件集合。

不确定您是如何在其他类的静态实用程序方法中正常工作的（根据注释，此方法是GridViewExportUtil类的一部分），但无论如何，修复它只是传递实例父控件（可以是页面）作为附加输入：

public static void Export(string fileName, GridView gv, System.Web.UI.Control parentControl)
{
    ...
    parentControl.Controls.Add(form);
    ...
}

在您调用它的页面上，确保传递页面对象：

GridViewExportUtil.Export("some file name", GridView1, this);

错误：名称＆＃39; Controls＆＃39;在当前上下文中不存在

1 个答案: