How to Set Master Page Content to Child Page

In this blog, I will explain how we can access or read Master page controls from Child Page or Content Page.

First Add some controls in Master Page to read from Child Page

<div class="main">
      <asp:Label ID="lblMaster" runat="server" Text="Master Label"></asp:Label>
      <asp:TextBox ID="txtMaster" runat="server"  placeholder="Master Textbox" ></asp:TextBox>
      <asp:ContentPlaceHolder ID="MainContent" runat="server" />
</div>

Add Some controls in Child Page

<asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="Server">
  <br />
  <hr />
  <asp:Button ID="btnGetMasterPageContent" runat="server" Text="Get Master Page Content" OnClick="btnGetMasterPageContent_Click" />
  <asp:Button ID="btnSetMasterPageContent" runat="server" Text="Set Master Page Content" OnClick="btnSetMasterPageContent_Click" />
  <br /><br />
  <asp:Label ID="lblChild" runat="server" Text="Child Label"></asp:Label>
  <asp:TextBox ID="txtChild" placeholder="Child Textbox" runat="server"></asp:TextBox>
</asp:Content>

Now Child Page Code behind

protected void btnGetMasterPageContent_Click(object sender, EventArgs e)
{
  Label lblMaster = (Label)Master.FindControl("lblMaster");
  TextBox txtMaster = (TextBox)Master.FindControl("txtMaster");

  if (lblMaster != null)
  {
    lblChild.Text = lblMaster.Text;
  }
  if (txtMaster != null)
  {
    txtChild.Text = txtMaster.Text;
  }
}
protected void btnSetMasterPageContent_Click(object sender, EventArgs e)
{
  Label lblMaster = (Label)Master.FindControl("lblMaster");
  TextBox txtMaster = (TextBox)Master.FindControl("txtMaster");

  if (lblMaster != null)
    lblMaster.Text = lblChild.Text;
  if (txtMaster != null)
    txtMaster.Text = txtChild.Text;
}

Note: Hope now you can Access Master Page Contents as well as can set also data from child page.