如何摆脱2个视图之间的空间

Question

我有一个UITableView，其下面有一个iAd Banner。我将constraints应用于他们：

的TableView

iAd Banner

有时，当我运行应用时，banners和tableView之间有一个空格（banner高度的数量）在banner加载之后。这很奇怪，因为它有时只会发生。我无法确定它何时发生以及何时发生。

但是当有空间并且我旋转iPhone时，我收到以下消息：

[4381:133861] Unable to simultaneously satisfy constraints.
    Probably at least one of the constraints in the following list is one you don't want. Try this: (1) look at each constraint and try to figure out which you don't expect; (2) find the code that added the unwanted constraint or constraints and fix it. (Note: If you're seeing NSAutoresizingMaskLayoutConstraints that you don't understand, refer to the documentation for the UIView property translatesAutoresizingMaskIntoConstraints) 
(
    "<NSLayoutConstraint:0x79039930 V:[UILabel:0x79039800'00:45'(57)]>",
    "<NSLayoutConstraint:0x79036f30 V:[UIButton:0x79036d50'First'(60)]>",
    "<NSLayoutConstraint:0x79035f80 V:[UIButton:0x79036620'second'(60)]>",
    "<NSLayoutConstraint:0x79039ec0 V:|-(8)-[UILabel:0x79039800'00:45']   (Names: '|':UIView:0x79039d00 )>",
    "<NSLayoutConstraint:0x79039f80 V:[UILabel:0x79039800'00:45']-(8)-[UIButton:0x79036d50'First']>",
    "<NSLayoutConstraint:0x7903a070 V:[UIButton:0x79036d50'First']-(8)-[UIButton:0x79036620'second']>",
    "<NSLayoutConstraint:0x7903a0a0 V:[UIButton:0x79036620'second']-(0)-|   (Names: '|':UIView:0x79039d00 )>",
    "<NSLayoutConstraint:0x79038240 V:|-(0)-[ADDimmerView:0x7861e140]   (Names: '|':ADBannerView:0x79037290 )>",
    "<NSLayoutConstraint:0x790382b0 V:[ADDimmerView:0x7861e140]-(0)-|   (Names: '|':ADBannerView:0x79037290 )>",
    "<NSLayoutConstraint:0x7903abb0 V:[_UILayoutGuide:0x7903a1e0]-(0)-[UIView:0x79039d00]>",
    "<NSLayoutConstraint:0x7903ac40 V:[UIView:0x79039d00]-(8)-[UITableView:0x78c02a00]>",
    "<NSLayoutConstraint:0x7903aca0 ADBannerView:0x79037290.bottom == _UILayoutGuide:0x7903a730.top>",
    "<NSLayoutConstraint:0x7903acd0 V:[UITableView:0x78c02a00]-(0)-[ADBannerView:0x79037290]>",
    "<_UILayoutSupportConstraint:0x790356e0 V:[_UILayoutGuide:0x7903a1e0(64)]>",
    "<_UILayoutSupportConstraint:0x790357b0 V:|-(0)-[_UILayoutGuide:0x7903a1e0]   (Names: '|':UIView:0x79039c40 )>",
    "<_UILayoutSupportConstraint:0x79035920 V:[_UILayoutGuide:0x7903a730(0)]>",
    "<_UILayoutSupportConstraint:0x79035680 _UILayoutGuide:0x7903a730.bottom == UIView:0x79039c40.bottom>",
    "<NSLayoutConstraint:0x79045280 'UIView-Encapsulated-Layout-Height' V:[UIView:0x79039c40(270)]>"
)

Will attempt to recover by breaking constraint 
<NSLayoutConstraint:0x79035f80 V:[UIButton:0x79036620'second'(60)]>

Make a symbolic breakpoint at UIViewAlertForUnsatisfiableConstraints to catch this in the debugger.
The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in <UIKit/UIView.h> may also be helpful.

我怎样摆脱那个空间？

这是我的代码：

func bannerViewDidLoadAd(banner: ADBannerView!) {
    self.bottomAddView?.hidden = false
}

func bannerView(banner: ADBannerView!, didFailToReceiveAdWithError error: NSError!) {
    self.bottomAddView?.hidden = true
}

Answer 1

您可能需要为iAd横幅添加一个约束高度，看看是否可以修复它。