iPad application always opens in portrait mode

The app uses a UISplitView and it always开发者_如何转开发 opens in portrait mode. If the iPad is held horizontally it will open in portrait mode and then rotate to landscape. I'd like it to just open up in landscape mode without needing to rotate. Any ideas>

In Info.plist, set UIInterfaceOrientation to UIInterfaceOrientationLandscapeRight (or Left). See the Information Property List Key Reference for more details including how to have different orientations for iPhone versus iPad.