如何在异步回发后保持对同一控件的关注
本文关键字:控件 异步 | 更新日期: 2023-09-27 18:08:06
我有3个文本框,一个是在updatepanel,它将刷新每4秒。在刷新期间,不在更新面板中的控件也会失去焦点。我想把重点放在那些控件上。
下面是我的代码:<asp:UpdatePanel ID="upnlChat" runat="server">
<ContentTemplate >
<asp:TextBox ID="txtChatBox" ReadOnly="true" TextMode="MultiLine"
CssClass="mymultitextboxclass" runat="server"></asp:TextBox>
</ContentTemplate>
<Triggers>
<asp:AsyncPostBackTrigger ControlID="timerChat" />
</Triggers>
</asp:UpdatePanel>
<asp:Timer ID="timerChat" Interval="4000" runat="server" ontick="timerChat_Tick" ></asp:Timer>
<table>
<tr><td>User: </td><td colspan="2"><asp:TextBox ID="txtUser" runat="server" ></asp:TextBox><br /></td>
<td>
<asp:RequiredFieldValidator ID="RequiredUserName" runat="server" ErrorMessage="Username Required" ControlToValidate="txtUser" ></asp:RequiredFieldValidator> </td></tr>
<tr><td>Message: </td><td><asp:TextBox ID="txtMsg" CssClass="mymsg" TextMode="MultiLine" onkeydown="if (event.keyCode == 13) { btnSend.focus(); this.form.submit(); }" runat="server"></asp:TextBox></td>
<td colspan="2"><asp:Button ID="btnSend" runat="server" onclick="btnSend_Click"
OnClientClick="scroll()" Text="send" />
</td></tr>
</table>
有谁能帮帮我吗?
这是@Darshan的脚本稍微修改的版本,使用jQuery。我喜欢他的解决方案,因为这个脚本将与所有的UpdatePanels工作,所以你不必专门为每个UpdatePanel编写代码。
我的修改是:
- 使用jQuery
- 执行空检查
- 不污染全局命名空间
- 编辑: tab与autoostback的文本框一样工作
/* Retain element focus after UpdatePanel postback
***************************************************/
jQuery(function ($) {
var focusedElementId = "";
var prm = Sys.WebForms.PageRequestManager.getInstance();
prm.add_beginRequest(function (source, args) {
var fe = document.activeElement;
if (fe != null) {
focusedElementId = fe.id;
} else {
focusedElementId = "";
}
});
prm.add_endRequest(function (source, args) {
if (focusedElementId != "") {
$("#" + focusedElementId).focus();
}
});
});
Chosen.jQuery
这个版本将与选择的jQuery插件一起工作。
/* Retain element focus after UpdatePanel postback
***************************************************/
jQuery(function ($) {
var focusedElementSelector = "";
var prm = Sys.WebForms.PageRequestManager.getInstance();
prm.add_beginRequest(function (source, args) {
var fe = document.activeElement;
focusedElementSelector = "";
if (fe != null) {
if (fe.id) {
focusedElementSelector = "#" + fe.id;
} else {
// Handle Chosen Js Plugin
var $chzn = $(fe).closest('.chosen-container[id]');
if ($chzn.size() > 0) {
focusedElementSelector = '#' + $chzn.attr('id') + ' input[type=text]';
}
}
}
});
prm.add_endRequest(function (source, args) {
if (focusedElementSelector) {
$(focusedElementSelector).focus();
}
});
});
http://www.codeproject.com/Tips/674414/Set-Focus-on-the-Same-Control-after-Postback-using
检查这个,这可能有助于你理解
哦,好的问题是ASP。. NET Javascript方法"WebForm_AutoFocus(…)"在部分页面更新后不执行,因此您不能在codebbehind类中使用内置函数SetFocus(clientID)。我的解决方案注册了两个事件处理程序,一个用于beginRequest,一个用于endRequest。在事件方法"beginRequest"中,我保存了客户端控件id。在endRequest方法中,我使用这个值来设置焦点,例如:代码:
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="shipper.aspx.cs" Inherits="shipper" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head id="Head1" runat="server">
<title>Restore Focus after background postback</title>
<script language="javascript">
var postbackElement = null;
function RestoreFocus(source, args)
{
document.getElementById(postbackElement.id).focus();
}
function SavePostbackElement(source, args)
{
postbackElement = args.get_postBackElement();
}
function AddRequestHandler()
{
var prm = Sys.WebForms.PageRequestManager.getInstance();
prm.add_endRequest(RestoreFocus);
prm.add_beginRequest(SavePostbackElement);
}
</script>
</head>
<body onload="AddRequestHandler()">
<form id="form1" runat="server">
<asp:ScriptManager ID="sm" runat="server"></asp:ScriptManager>
<div>
<asp:UpdatePanel runat="server" ID="updPanel1">
<ContentTemplate>
<asp:Panel ID="panel1" runat="server">
<asp:RadioButtonList ID="rbList" runat="server" AutoPostBack="true">
<asp:ListItem Text="Rb 1" Value="1"></asp:ListItem>
<asp:ListItem Text="Rb 2" Value="2"></asp:ListItem>
<asp:ListItem Text="Rb 3" Value="3"></asp:ListItem>
<asp:ListItem Text="Rb 4" Value="4"></asp:ListItem>
<asp:ListItem Text="Rb 5" Value="5"></asp:ListItem>
</asp:RadioButtonList><br />
<asp:DropDownList ID="ddSample" runat="server" AutoPostBack="true">
<asp:ListItem Text="Item 1" Value="1"></asp:ListItem>
<asp:ListItem Text="Item 2" Value="2"></asp:ListItem>
<asp:ListItem Text="Item 3" Value="3"></asp:ListItem>
</asp:DropDownList>
</asp:Panel>
</ContentTemplate>
</asp:UpdatePanel>
</div>
</form>
</body>
</html>
on timerChat_Tick event .do this....
txtChatBox.Focus();