Ajax second postback not working in Sharepoint in UpdatePanel-优快云博客

本文介绍了一种解决SharePoint中使用ASP.NET AJAX UpdatePanel时出现的第二次PostBack失败的方法。通过禁用Windows SharePoint Services JavaScript中的formonSubmit包装器，可以避免特定URL场景下导致的问题，并确保UpdatePanel正常工作。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

We have one problem in work, we spend with that two days without any solution, all we found cause some another problem. This is what help us when the page is not making second postback in update panel when the first postback is fired by element in UpdatePanel and refresh only update panels on the page.

Taken from Mike Ammerlaan’s Blog

Windows SharePoint Services JavaScript has a “form onSubmit wrapper” which is used to override the default form action. This work is put in place to ensure that certain types of URLs, which may contain double byte characters, will fully work across most postback and asynchronous callback scenarios. However, if your scenarios do not involve double byte character URLs, you may successful disable this workaround and gain the ability to use ASP.NET AJAX UpdatePanels.

To do this, you may need to register a client startup script which disables this workaround, in addition to resetting the default form action:

view plain copy to clipboard print ?

<script type='text/javascript'>
_spOriginalFormAction = document.forms[0].action;
_spSuppressFormOnSubmitWrapper=true;
</script>

This script may be directly embedded in the page, or could be emitted by a control that uses the UpdatePanel. The following is an example of a very simple method which will fix this issue:

view plain copy to clipboard print ?

private void EnsureUpdatePanelFixups()
{
if (this.Page.Form != null)
{<br />
string formOnSubmitAtt = this.Page.Form.Attributes["onsubmit"];
if (formOnSubmitAtt == "return _spFormOnSubmitWrapper();")
{
this.Page.Form.Attributes["onsubmit"] = "_spFormOnSubmitWrapper();";
}
}
ScriptManager.RegisterStartupScript(this, typeof(AjaxUpdatePanelPart), "UpdatePanelFixup", "_spOriginalFormAction = document.forms[0].action; _spSuppressFormOnSubmitWrapper=true;", true);
}