Question

This is for iOS4 with multitask issue. How do I reload view after my app is re-appear from background running app?

Answer 1

You want your view controller to listen for UIApplicationWillEnterForegroundNotification:

Posted shortly before an application
leaves the background state on its way
to becoming the active application.

Also mentioned in the iOS Application Programming Guide:

The
UIApplicationWillEnterForegroundNotification
notification is also available for
tracking when your application
reenters the foreground. Objects in
your application can use the default
notification center to register for
this notification.

In your handler for this notification, you can trigger whatever refreshing/redrawing you need.

You can read more about Notifications in the Cocoa Core Competencies document.