iOS 8自动高度单元在第一次加载时不正确

I have an iOS 8 application where I have a search results page that each cell is autosized based on the height of a certain label. However, after the view first loads the cells that are displayed don't autosize. After you scroll down the cells that follow are sized correctly. I am wiring up the auto layout constraints in my storyboard. I have the following code in viewDidLoad.I have an iOS 8 application where I have a sear