//在viewDidLoad中加入:
if ([self respondsToSelector:@selector (edgesForExtendedLayout)])
{
self.edgesForExtendedLayout = UIRectEdgeNone;
}
//在viewDidLoad中加入:
if ([self respondsToSelector:@selector (edgesForExtendedLayout)])
{
self.edgesForExtendedLayout = UIRectEdgeNone;
}