ListView Footer in iOS, wrong position

Hello.
I'm use Xamarin.Forms 1.4.3.6358-pre2.
The ListView footer declare like this :

<ListView.Footer>



</ListView.Footer>

But , you can see the result :
http://images0.cnblogs.com/blog2015/154354/201505/181605361354041.png

wrong position.
The old version has some exception in ios, so I only can use this version.