I added some logging statements to figure out what the lifecycle of user controls implementing SLX smart parts was and how it meshed with the standard ASP.NET events. This is what I came up with. SLX-specific events are in italic – the rest are standard ASP.NET (I skipped a few of the ASP.NET ones).

When the smart part is not displayed (eg an undisplayed dialog), none of the SLX stuff fires, but the standard ASP.NET still does:

• OnInit
• OnLoad
• OnUnload

EntityContext.GetEntity() is available at all time but is of the type that is bound to the main form – not necessarily the same as the smartpart’s.

The first time it is displayed and bound:

• OnInit
• OnLoad
• OnAddEntityBindings
• OnLoadCurrentEntity starts
• OnCurrentEntitySet
• OnLoadCurrentEntity returns
• MyDialogOpening
• OnPreRender
• OnFormBound (which is actually called from OnPreRender)
• OnUnload

Again, EntityContext.GetEntity() is available but is of the type of the main form until OnCurrentEntitySet.

On postbacks:

• OnAddEntityBindings
• OnInit
• OnLoad Starts
• OnLoadCurrentEntity starts
• OnCurrentEntitySet
• OnLoadCurrentEntity returns
• OnLoad Returns
• Control postback events
• OnPreRender
• OnFormBound (which is actually called from OnPreRender)
• OnUnload

EntityContext.GetEntity() is available and of the correct type.

OnFormBound is not a bad place to hook data binding stuff but it only fires from the PreRender which is a bit late sometimes. OnCurrentEntitySet executes before the bound data is saved to the entity (therefore before any SLX property change handler fires) so it is usually not great either.