PreInit
Use this event for the following:
• Check the IsPostBack property to determine whether this is the first time the page is
being processed.
• Create or re-create dynamic controls.
• Set a master page dynamically.
• Set the Theme property dynamically.
• Read or set profile property values.
Note: If the request is a postback, the values of the controls have not yet been restored from view state. If you set a control property at this stage, its value might be overwritten in the next event.
Init
Raised after all controls have been initialized and any skin settings have been applied. Use this event to read or initialize control properties.
InitComplete
Raised by the Page object. Use this event for processing tasks that require all initialization
be complete.
PreLoad
Use this event if you need to perform processing on your page or control before the Load
event. After the Page raises this event, it loads view state for itself and all controls, and
then processes any postback data included with the Request instance.
Load
The Page calls the OnLoad event method on the Page, then recursively does the same for
each child control, which does the same for each of its child controls until the page and all
controls are loaded.
Control events
Use these events to handle specific control events, such as a Button control's Click event or
a TextBox control's TextChanged event. In a postback request, if the page contains
validator controls, check the IsValid property of the Page and of individual validation
controls before performing any processing.
LoadComplete
Use this event for tasks that require that all other controls on the page be loaded.
PreRender
Before this event occurs:
• The Page object calls EnsureChildControls for each control and for the page.
• Each data bound control whose DataSourceID property is set calls its DataBind
method.
• The PreRender event occurs for each control on the page. Use the event to make final
changes to the contents of the page or its controls.
SaveStateComplete
Before this event occurs, ViewState has been saved for the page and for all controls. Any
changes to the page or controls at this point will be ignored. Use this event perform tasks
that require view state to be saved, but that do not make any changes to controls.
Render
This is not an event; instead, at this stage of processing, the Page object calls this method
on each control. All ASP.NET Web server controls have a Render method that writes out
the control's markup that is sent to the browser. If you create a custom control, you
typically override this method to output the control's markup. However, if your custom
control incorporates only standard ASP.NET Web server controls and no custom markup,
you do not need to override the Render method. A user control (an .ascx file) automatically
incorporates rendering, so you do not need to explicitly render the control in code.
Unload
This event occurs for each control and then for the page. In controls, use this event to do
final cleanup for specific controls, such as closing control-specific database connections. For
the page itself, use this event to do final cleanup work, such as closing open files and
database connections, or finishing up logging or other request-specific tasks. Note: During
the unload stage, the page and its controls have been rendered, so you cannot make
further changes to the response stream. If you attempt to call a method such as the
Response.Write method, the page will throw an exception.
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