通过ajax/javascript返回CollapsiblePanelExtender

Question

我希望能够通过javascript返回一个以编程方式生成的可折叠面板扩展器，以及它的面板等等。我已经让面板和相关的表格通过了，但是当我尝试连接cpe时，它就坏了。并返回错误：

cpe面板等由WebService生成，我尝试让JS将get服务动态返回到特定字段的内容写入

Microsoft JScript runtime error: Sys.Net.WebServiceFailedException: The server method 'Sub_Menu_Helper' failed with the following error: System.InvalidOperationException-- Page cannot be null. Please ensure that this operation is being performed in the context of an ASP.NET request.

                {
                    Label somelabel = new Label();
                    somelabel.ID = somenumber.ToString();
                    somelabel.Text = somenumber.ToString();
                    subpnlContent.Controls.Add(somelabel);
                    ++somenumber;
                }

                CollapsiblePanelExtender cpeMenuLast = new CollapsiblePanelExtenderEx();
                cpeMenuLast.ID = "subcpe" + strMenuId + strParentHierarchyIds;
                cpeMenuLast.TargetControlID = "subpnlContent" + strParentMenuId + "_" + strMenuId;
                cpeMenuLast.ExpandControlID = "cellContent" + strParentMenuId + "_" + strMenuId;
                cpeMenuLast.CollapseControlID = "cellContent" + strParentMenuId + "_" + strMenuId;
                cpeMenuLast.Collapsed = bCollapsed;
                cpeMenuLast.TextLabelID = strMenuName;
                cpeMenuLast.ExpandedText = m_strButtonLabelHide;
                cpeMenuLast.CollapsedText = m_strButtonLabelShow;
                cpeMenuLast.ImageControlID = "imglnk" + strMenuId;
                cpeMenuLast.CollapsedImage = "~/App_Themes/default/nbExpand.gif";
                cpeMenuLast.ExpandedImage = "~/App_Themes/default/nbCollapse.gif";
                cpeMenuLast.SuppressPostBack = true;
                cpeMenuLast.ScrollContents = false;

                //Add Everything
                cellSubMenu.Controls.Add(subpnlContent);
                cellSubMenu.Controls.Add(cpeMenuLast);
                row.Cells.Add(cellSubMenu);
                tbl.Rows.Add(row);

                using (StringWriter sw = new StringWriter(sb))
                {
                    using (HtmlTextWriter tw = new HtmlTextWriter(sw))
                    {
                        tbl.RenderControl(tw);
                    }
                }

我该如何解决这个问题呢？

Answer 1

看起来您需要一个带有ScriptManager的Page对象来呈现CollapsiblePanelExtender，这是有意义的，因为您需要一些脚本才能正常工作。

因此，也许您可以尝试以下方法来呈现您的表：

var page = new Page();
page.Controls.Add(new ScriptManager());
page.Controls.Add(tbl);
var writer = new StringWriter();
HttpContext.Current.Server.Execute(page, writer, false);
return writer.ToString();

奥利弗