How to change MasterPage's label from Content page without refreshing page
Question
I've got MasterPage and Content Page. On the ContentPage there is some label and i want to change it's text when clicked on button on the content page without refreshing the page.
Default.aspx
<%@ Page Title="" Language="C#" MasterPageFile="~/MasterPage.master" %>
<script runat="server">
protected void ImageButton1_Click(object sender, ImageClickEventArgs e)
{
Label SensorTemperatureLabel = (Label)this.Master.FindControl("SensorTemperatureLabel");
if (SensorTemperatureLabel != null)
{
SensorTemperatureLabel.Text = "TEST";
}
}
</script>
<asp:Content ID="Content1" ContentPlaceHolderID="ContentPlaceHolder1" Runat="Server">
<asp:ImageButton ID="ImageButton1" runat="server" OnClick="ImageButton1_Click" />
</asp:Content>
MasterPage.master Part of the code with label
<div class="sidebar">
<!-- insert your sidebar items here -->
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<ContentTemplate>
<asp:Label ID="SensorTemperatureLabel" runat="server" Text="Label"></asp:Label>
</ContentTemplate>
</asp:UpdatePanel>
</div>
3 answers
solution1
1 2012-11-23 18:44:54
If the label is not in <ContentTemplate /> , you can access with javascript
var SensorTemperatureLabel = document.getElementById("<%=SensorTemperatureLabel%>");
SensorTemperatureLabel.innerHTML = "newValue";
Otherwise, the ID is generated and you'll need
var SensorTemperatureLabel = document.getElementById("<%= this.Master.FindControl("SensorTemperatureLabel").ClientID %>");
solution2
1 ACCPTED 2012-11-23 18:52:30
I have prepared you complete solution to show you how you can do this.
First sample master. Take notice I have added ScriptManager to page and target label is inside content template:
<%@ Master Language="C#" AutoEventWireup="true" CodeBehind="Site1.master.cs" Inherits="WebTester.Site1" %>
<!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 runat="server">
<title></title>
</head>
<body>
<form id="form1" runat="server">
<asp:ScriptManager ID="ScriptManager1" runat="server">
</asp:ScriptManager>
<div>
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<ContentTemplate>
<asp:Label ID="SensorTemperatureLabel" runat="server" Text="TEMP"></asp:Label>
</ContentTemplate>
</asp:UpdatePanel>
<asp:ContentPlaceHolder ID="ContentPlaceHolder1" runat="server">
</asp:ContentPlaceHolder>
</div>
</form>
</body>
</html>
Now here is content page, button is also placed inside content template:
<%@ Page Title="" Language="C#" MasterPageFile="~/Site1.Master" AutoEventWireup="true" CodeBehind="WebForm1.aspx.cs" Inherits="WebTester.WebForm1" %>
<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" runat="server">
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<ContentTemplate>
<asp:Button ID="Button1" runat="server" onclick="Button1_Click" Text="Test" />
</ContentTemplate>
</asp:UpdatePanel>
</asp:Content>
And finally here is the code, I get refrence to label by using FindControl:
protected void Button1_Click(object sender, EventArgs e)
{
Site1 site = this.Master as Site1;
if (site != null)
{
Label SensorTemperatureLabel = site.FindControl("SensorTemperatureLabel") as Label;
SensorTemperatureLabel.Text = DateTime.Now.ToString();
}
}
This code will update label on master page without complete page postback.
solution3
0 2017-08-11 00:37:34
I hope my answer help in this case if you have Label in master page named " Label1" then you can change value there like this VB
Dim lb as label= me.master.findcontrol("Label1"):lb.text="Hello worold"
Peace upon you all.
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