Creating Master Page in ASP.NET

Creating Master Page:

·         Open Visual Studio.

·         Create new ASP.NET Web site, enter name as MasterPagesApp.

·         Select Location as File System, and enter the path as D:\MyWebSites\MasterPagesApp (or any other path).

·         Select the Language which you are comfortable, for this I used C#.

·         After creating the new Web Site, you will find a page created for you named Default.aspx.

·         Delete this page and right click the application from solution explorer. Select Add New Item, select Master Page from installed Visual Studio templates and name it MainLayout, and check the Place code in separate file checkbox; this will create you a code-behind in the language you select, we work here using C#.

The MainLayOut.master will be open in Source view.  You will find this master page directive at the beginning:

<%@ Master AutoEventWireup="true" CodeFile="MainLayOut.master.cs" Inherits="MainLayOut" Language="C#" >

As you see, the attributes of the Master directive is common to the ones of the Page directive, and they are self-descriptive.

·         CodeFile is the path of the code behind file and it can be VB or C#, note that in one Web Site you can mix between both languages.

·         Inherits decides the class within the code file to be used.

·         Language is the language of the code behind file.

·         AutoEventWireup is so important; for any page there is an automatic way to bind the events to methods in the same aspx file or in code behind.  If this attribute is true, Page events are automatically bound to methods that are using naming convention as Page_event.  For example Page_Load, Page_Init, and Page_PreInit (this is the event fired before creating the controls of the page).  This is one disadvantage that the standard events of the page should adhere to this naming convention, but if you set it to false, it will give you more flexibility to use any names for the event handlers. in VB.NET.

See ContentPlaceHolder section:

<asp:contentplaceholder id="ContentPlaceHolder1" runat="server"> </asp:contentplaceholder>

This server control is the most important for the master pages as this is the zone in which the content pages will be rendered.

Next, do the following:

·         Switch to the Design of the master page, you will get the ContentPlaceHolder1 shown, now you can design the master page just as any aspx page, so for this practice we'll do a simple master page.

·         From Layout menu select Insert Table, Select Template option, then select Header, footer and side, then drag the ContentPlaceHolder1 control into the right middle cell of the table you have just added.

·         Add one label into the left middle cell, and the logo of CodeProject to the upper cell of the table, you should have the same as in the following figure

·         Double click anywhere at the master page. This will open the code behind and will add the Page_Load event handler and write the following code:

Label1.Text = "The Time of Server is: " + DateTime.Now.TimeOfDay;

The above code will show the time of the server at the label.

Creating Content Page:

You should know that the content page is just one aspx page, but you bind this page to one master page while you are creating it.  To do this, right click your web application from solution explorer and select Add New Item, select Web Form from the installed templates and check Select Maser Page, enter the name of the new page as myContentPage.aspx.

The page you have just added will open in source view and you will find one entry.  Add the MasterPageFile attribute set to the value of the master page file you have selected before.  You will also find one Content server control added by default and the attribute ContentPlaceHolderID assigned to ContentPlaceHolder1.  This is the default value which refers to the ContentPlaceHolder control at the master page and if you have renamed this control at the master page, you should change it now to the correct ID.  This sets the zone in which this content page will be shown as we said before.

Switch to the design view of MyContentPage.aspx.  You will get all the master page contents added by all the contents of the master page is dim because they are not editable, only the Content1 will be enabled if you click the white area, and you can now add any controls just as you do for any aspx page.

Double click the white area of Content1, you will get the event handler of Page_Load, add the following code:

Label1.Text = this.MasterPageFile;

The above code will show the path of the Master Page file in the label.

Saving Master Page path in web.config:

There is one technique by which we can make all the pages comprising our web application as content pages and we can bind all the pages to one master page, this master page that will be a template to our entire application.  It is advisable to save the path of this master page in web.config that we can do as following:

<configuration>

<pages masterpagefile="~/sitetemplate.master">

</configuration>

If you specify a MasterPageFile for your page, it will override your web.config value but the importance of the value of web.config is that it guarantees that all the pages added to your application are bound to this master page file.  So, if you have more than one master page, you can just change the web.config value, and this will update the whole application pages with no need of recompilation.