Explain ASP.NET Webform Page life Cycle?
ASP.NET page passes through a series of steps during its life cycle. Following is the high-level explanation of life cycle stages/steps.
Initialization: Controls raise their Init event in this stage.Objects and variables are initializes for complete lifecyle of request. LoadViewState: is a post back stage and loads the view state for the controls that enabled its view state property. LoadPostBackData: is also a post back stage and loads the data posted for the controls and update them.
In this stage page as well as all the controls raise their Load event. Till this stage all the controls are initialized and loaded. In most of the cases, we are coding this event handler.
is again a postback stage. For example, it's raise against a button click event. We can easily put our code here to perform certain actions.
SaveViewState: Finally, controls state is saved in this stage before Rendering HTML. Render: This is the stage where HTML is generated for the page.
Lastly, all objects associated with the request are cleaned up.
What is the difference between custom controls and user controls?
Custom controls are basically compiled code i.e. DLLs. These can be easily added to toolbox, so it can be easily used across multiple projects using drag and drop approach. These controls are comparatively hard to create. But User Controls (.ascx) are just like pages (.aspx). These are comparatively easy to create but tightly couple with respect to User Interface and code. In order to use across multiple projects, we need to copy and paste to the other project as well.
What are the types of Authentication in ASP.NET?
There are three types of authentication available in ASP.NET:
  • Windows Authentication: This authentication method uses built-in windows security features to authenticate user.
  • Forms Authentication: authenticate against a customized list of users or users in a database.
  • Passport Authentication: validates against Microsoft Passport service which is basically a centralized authentication service.