Question

What are master pages?

Answer 1

Some points about Master Pages,

1. The extension of MasterPage is '.master'.
2. MasterPage cannot be directly accessed from the client because it just acts as a template for the other Content Pages.
3. In a MasterPage we can have content either inside ContentPlaceHolder or outside it. Only content inside the ContentPlaceHolder can be customized in the Content Page.
4. We can have multiple masters in one web application.
5. A MasterPage can have another MasterPage as Master to it.
6. The content page content can be placed only inside the content tag.
7. Controls of MasterPage can be programmed in the MasterPage and content page but a content page control will never be programmed in MasterPage.
8. A master page of one web application cannot be used in another web application.
9. The MasterPageFile property of a webform can be set dynamically and it should be done either in or before the Page_PreInit event of the WebForm. Page.MasterPageFile = "MasterPage.master". The dynamically set Master Page must have the ContentPlaceHolder whose content has been customized in the WebForm.
10. The order in which events are raised: Load (Page) a Load (Master) a LoadComplete (Page) i.e. if we want to overwrite something already done in Load event handler of Master then it should be coded in the LoadComplete event of the page.
11. Page_Load is the name of method for event handler for Load event of Master. (it's not Master_Load).