how to access master page control from content page

In the MasterPage.cs file add the property of Label like this:

public string ErrorMessage{    get    {        return lblMessage.Text;    }    set    {        lblMessage.Text = value;    }}

On your aspx page, just below the Page Directive add this:

<%@ Page Title="" Language="C#" MasterPageFile="Master Path Name"..... %><%@ MasterType VirtualPath="Master Path Name" %>   // Add this

And in your codebehind(aspx.cs) page you can then easily access the Label Property and set its text as required. Like this:

this.Master.ErrorMessage = "Your Error Message here";

asp.net master-pages code-behind

In Content page you can access the label and set the text such as

Here 'lblStatus' is the your master page label ID

Label lblMasterStatus = (Label)Master.FindControl("lblStatus");lblMasterStatus.Text  = "Meaasage from content page";

asp.net master-pages code-behind

It Works

To find master page controls on Child page

Label lbl_UserName = this.Master.FindControl("lbl_UserName") as Label;                    lbl_UserName.Text = txtUsr.Text;

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