ASP.NET master pages allow you to create a consistent layout for the pages in
your application. A single master page defines the look and feel and standard
behavior that you want for all of the pages in your website. A master page can
serve as a template for one or more web forms
Advantages of using master pages
They allow you to centralize the common functionality of your pages so that you
can make updates in just one place.
They make it easy to create one set of controls and code and apply the results
to a set of pages. For example, you can use controls on the master page to
create a menu that applies to all pages.
They provide an object model that allows you to customize the master page from
individual content pages
Important points about master pages:
A master page is defined with the file extension .master
Master pages contain a @ Master directive.
ContentPlaceHolder controls is only available for Master Pages
To enable pages to insert content into a master page, add one or more
ContentPlaceHolder controls
You must have a Content control on a content page. one Content control is
Added to the page for each ContentPlaceHolder control inside the master page.
An ASP.NET page that uses Master Pages is called content pages.
Referencing Master Page Properties and Controls from Content Pages
You can easily access the property and controls that is available on master
pages.
The basic steps to reference master page properties from a content page are as
follows:
1. Create a property in the master page code-behind file.
2. Add the @ MasterType directives to the .aspx content page and use the
attribute “VirtualPath”.
3. Reference the master page property from the content page using the syntax
Master.<Property_Name>.
Creating a Property in the Master Page
// txtName is the ID of TextBox in Master Page
public String EmpName
{
get { return
txtName.Text; }
set {
txtName.Text = value; }
}
Connecting to Master Page Properties from Content Pages
You must add the @ MasterType declaration to the .aspx content page to reference
master properties in a content page.
<%@ MasterType VirtualPath="~/MasterPageName.master" %>
Now you can reference properties in the master page using the Master class.
Lable1.Text=Master.EmpName
Referencing Controls in the Master Page
You can also reference a control on the master page from a content page through
the Master.FindControl method.
The return type of Master.FindControl is Control.So you have to cast it to
correct Control Type
