Part 146 - Why use master pages in asp.net

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It is common for a web site to have a consistent look and behaviour across all the pages in the web application. For example, we want all the pages in our application to have the layout as shown below.




To have a layout (similar to the one above) across all our pages, without the use of master pages. There are 2 options
Option 1: Copy and paste the following HTML across all pages in the application
<table style="font-family:Arial">
    <tr>
        <td colspan="2" style="width:800px; height:80px; background-color:#BDBDBD; 
            text-align:center">
            <h1>
                WebSite Header
            </h1>
        </td>
    </tr>
    <tr>
        <td style="height:500px; background-color:#D8D8D8; width:150px">
            <h3>Menu</h3>
        </td>
        <td style="height:500px; background-color:#E6E6E6; width:650px">
            <h2>This section changes on a page by page basis</h2>        
        </td>
    </tr>
    <tr>
        <td colspan="2" style="background-color:#BDBDBD; text-align:center">
            <b>Website Footer</b>
        </td>
    </tr>
</table>

The following are the problems with this approach
1. We have lot of duplicated HTML on every page
2. If we have to change something in the common layout, we will have to make the change in all the pages, which is time consuming and error prone.

Option 2: Implement the layout using the following user controls.
1. Header user control
2. Menu user control
3. Footer user control

The following are the problems with using user controls
1. We will end up with complicated HTML and CSS if we have to design the layout similar to the one in the above image
2. All the user controls have to be manually added on each and every page of the site

So, the best approach to have a consistent look and feel across all pages in a web application is to use master pages. We will discuss master pages in our next video.