Use

1. OnInit (Init)  -- Inializes all Child controls on the Page

2. LoadControlState  -- Loads the Control State 

3. LoadViewState -- Loads the View State

4. LoadPostData -- Control properties are set according to the received form data

5. Load -- Actions can be performed on the controls as all the pre-activities are complete by this time

6. RaisePostDataChangedEvent -- This event is raised if data has been changed in previous and Current Postbacks.

7. RaisePostBackEvent -- This event handles the user action that caused the Postback.

8. PreRender (OnPreRender) -- This event takes place between postback and saving viewstate. Till this stage changes will be saved to the control.

9. SaveControlState -- Self Explanatory

10. SaveViewState -- Self Explanatory

11. Render -- Generates artifacts at Client side (HTML,DHTML,Scripts) to properly display controls

12. Dispose -- Releases unmanaged Resource ( Database connections, file handles)

13. Unload -- Releases managed Resources ( Instances created by CLR)

You bet. Just call SetNoStore on the HttpCachePolicy object exposed through the Response object's Cache property, as demonstrated here:

SetNoStore works by returning a Cache-Control: private, no-store header in the HTTP response. In this example, it prevents caching of a Web page that shows the current time.

Most browsers recognize the following META tag as a signal to automatically refresh the page every nn seconds:

Here's an ASPX file that displays the current time of day. Once displayed, it automatically refreshes every 5 seconds:

Use the HtmlInputFile class, which you can declare an instance of with an <input type="file" runat="server"/> tag. The following example is a complete ASPX file that lets a user upload an image file and a comment descibing the image. The Upload_Click method writes the image and the comment to a table named Pictures in a SQL Server database named MyPictures.