［已解决］Swift中给UITableView和UIToolbar之间添加限制约束Constraint

        let heightConstraint:NSLayoutConstraint = NSLayoutConstraint(
            item: messageTableView, attribute: NSLayoutAttribute.Bottom, relatedBy: NSLayoutRelation.LessThanOrEqual, toItem: inputMessageToolbar, attribute: NSLayoutAttribute.Top, multiplier: 1.0, constant: 0)
        //<NSLayoutConstraint:0x7f8952785960 UITableView:0x7f8953863800.bottom <= UIToolbar:0x7f89525b8300.top>

heightConstraint.active = true

没有效果：

好像是因为：

自己手动设置了frame了？

translatesAutoresizingMaskIntoConstraints

参考：

iOS: 让自定义控件适应Autolayout注意的问题 | Mgen

UIView Class Reference

去设置

结果，点击出现输入框，应该出现键盘时，变成：

学习iOS 6.0的NSAutoLayout – [email protected]

学习AutoLayout（NSLayoutConstraint） – 简书

学习AutoLayout（VFL） – 简书

学习AutoLayout（UIScrollView） – 简书

学习AutoLayout（VFL中“-”的使用） – 简书

然后用代码：

        //add constraints for messageTableView
        self.messageTableView = UITableView()
        messageTableView.translatesAutoresizingMaskIntoConstraints = false
        let messageTopConstraint:NSLayoutConstraint = NSLayoutConstraint(
                item: messageTableView,
                attribute: NSLayoutAttribute.Top,
                relatedBy: NSLayoutRelation.Equal,
                toItem: chatView,
                attribute: NSLayoutAttribute.Top,
                multiplier: 1.0,
                constant: 0)
        let messageBottomConstraint:NSLayoutConstraint = NSLayoutConstraint(
                item: messageTableView,
                attribute: NSLayoutAttribute.Bottom,
                relatedBy: NSLayoutRelation.Equal,
                toItem: chatView,
                attribute: NSLayoutAttribute.Bottom,
                multiplier: 1.0,
                constant: (0 – toolbarHeight))
        let messageLeftConstraint:NSLayoutConstraint = NSLayoutConstraint(
                item: messageTableView,
                attribute: NSLayoutAttribute.Left,
                relatedBy: NSLayoutRelation.Equal,
                toItem: chatView,
                attribute: NSLayoutAttribute.Left,
                multiplier: 1.0,
                constant: 0)
        let messageRightConstraint:NSLayoutConstraint = NSLayoutConstraint(
                item: messageTableView,
                attribute: NSLayoutAttribute.Right,
                relatedBy: NSLayoutRelation.Equal,
                toItem: chatView,
                attribute: NSLayoutAttribute.Right,
                multiplier: 1.0,
                constant: 0)
        NSLayoutConstraint.activateConstraints([
                messageTopConstraint,
                messageBottomConstraint,
                messageLeftConstraint,

messageRightConstraint])

chatView.addSubview(self.messageTableView)

//        let inputToolbarView = UIView(frame: CGRectMake(
//            0,
//            0,
//            //TODO: adjust according to iPhone screen width
//            self.view.frame.width – 60, //iPhone5:260, iPhone:315
//            30))
//        print("inputToolbarView.frame=\(inputToolbarView.frame)")
        //for debug
        //inputToolbarView.backgroundColor = UIColor.greenColor()

        //add constraints
        let inputToolbarView = UIView()
        inputToolbarView.translatesAutoresizingMaskIntoConstraints = false
        let inputToolbarTopConstraint:NSLayoutConstraint = NSLayoutConstraint(
                item: inputToolbarView,
                attribute: NSLayoutAttribute.Top,
                relatedBy: NSLayoutRelation.Equal,
                toItem: chatView,
                attribute: NSLayoutAttribute.Bottom,
                multiplier: 1.0,
                constant: (0 – toolbarHeight))
        let inputToolbarBottomConstraint:NSLayoutConstraint = NSLayoutConstraint(
                item: inputToolbarView,
                attribute: NSLayoutAttribute.Bottom,
                relatedBy: NSLayoutRelation.Equal,
                toItem: chatView,
                attribute: NSLayoutAttribute.Bottom,
                multiplier: 1.0,
                constant: 0)
        let inputToolbarLeftConstraint:NSLayoutConstraint = NSLayoutConstraint(
                item: inputToolbarView,
                attribute: NSLayoutAttribute.Left,
                relatedBy: NSLayoutRelation.Equal,
                toItem: chatView,
                attribute: NSLayoutAttribute.Left,
                multiplier: 1.0,
                constant: 0)
        let inputToolbarRightConstraint:NSLayoutConstraint = NSLayoutConstraint(
                item: inputToolbarView,
                attribute: NSLayoutAttribute.Right,
                relatedBy: NSLayoutRelation.Equal,
                toItem: chatView,
                attribute: NSLayoutAttribute.Right,
                multiplier: 1.0,
                constant: 0)
        NSLayoutConstraint.activateConstraints([
                inputToolbarTopConstraint,
                inputToolbarBottomConstraint,
                inputToolbarLeftConstraint,

inputToolbarRightConstraint])

chatView.addSubview(inputMessageToolbar)

结果程序挂了：

2015-11-29 15:11:06.616 JianDao[50721:2654673] *** Terminating app due to uncaught exception ‘NSGenericException’, reason: ‘Unable to activate constraint with items <UITableView: 0x7fc7d209b600; frame = (0 0; 0 0); clipsToBounds = YES; gestureRecognizers = <NSArray: 0x7fc7d413ca10>; layer = <CALayer: 0x7fc7d1cf6760>; contentOffset: {0, 0}; contentSize: {0, 0}> and <UIView: 0x7fc7d413c2e0; frame = (0 0; 375 603); layer = <CALayer: 0x7fc7d413b910>> because they have no common ancestor. Does the constraint reference items in different view hierarchies? That’s illegal.’
*** First throw call stack:
(
0 CoreFoundation                      0x000000010a002f45 __exceptionPreprocess + 165
1 libobjc.A.dylib                     0x000000010929bdeb objc_exception_throw + 48
2 CoreFoundation                      0x000000010a002e7d +[NSException raise:format:] + 205
3 Foundation                          0x000000010901908e +[NSLayoutConstraint _addOrRemoveConstraints:activate:] + 383
4 JianDao                             0x000000010897e23f _TFC7JianDao26MessageTableViewController11viewDidLoadfS0_FT_T_ + 5823
5 JianDao                             0x00000001089804d2 _TToFC7JianDao26MessageTableViewController11viewDidLoadfS0_FT_T_ + 34
6 UIKit                               0x000000010aca4cc4 -[UIViewController loadViewIfRequired] + 1198
7 UIKit                               0x000000010acaac7b -[UIViewController __viewWillAppear:] + 120
8 UIKit                               0x000000010acdaa37 -[UINavigationController _startCustomTransition:] + 1203
9 UIKit                               0x000000010aceacdb -[UINavigationController _startDeferredTransitionIfNeeded:] + 712
10 UIKit                               0x000000010acebcea -[UINavigationController __viewWillLayoutSubviews] + 57
11 UIKit                               0x000000010ae91c85 -[UILayoutContainerView layoutSubviews] + 248
12 UIKit                               0x000000010abc6e40 -[UIView(CALayerDelegate) layoutSublayersOfLayer:] + 710
13 QuartzCore                          0x000000010a89259a -[CALayer layoutSublayers] + 146
14 QuartzCore                          0x000000010a886e70 _ZN2CA5Layer16layout_if_neededEPNS_11TransactionE + 366
15 QuartzCore                          0x000000010a886cee _ZN2CA5Layer28layout_and_display_if_neededEPNS_11TransactionE + 24
16 QuartzCore                          0x000000010a87b475 _ZN2CA7Context18commit_transactionEPNS_11TransactionE + 277
17 QuartzCore                          0x000000010a8a8c0a _ZN2CA11Transaction6commitEv + 486
18 UIKit                               0x000000010ab3d216 _afterCACommitHandler + 174
19 CoreFoundation                      0x0000000109f2e947 __CFRUNLOOP_IS_CALLING_OUT_TO_AN_OBSERVER_CALLBACK_FUNCTION__ + 23
20 CoreFoundation                      0x0000000109f2e8b7 __CFRunLoopDoObservers + 391
21 CoreFoundation                      0x0000000109f2450b __CFRunLoopRun + 1147
22 CoreFoundation                      0x0000000109f23e08 CFRunLoopRunSpecific + 488
23 GraphicsServices                    0x000000010e6a3ad2 GSEventRunModal + 161
24 UIKit                               0x000000010ab1230d UIApplicationMain + 171
25 JianDao                             0x000000010890d2bd main + 109
26 libdyld.dylib                       0x000000010c9ce92d start + 1
27 ???                                 0x0000000000000001 0x0 + 1
)

libc++abi.dylib: terminating with uncaught exception of type NSException

难道是顺序错了？

那么把那些约束条件，放到最后：

chatView.addSubview(self.messageTableView)

chatView.addSubview(inputMessageToolbar)

        //add constraints for messageTableView
        messageTableView.translatesAutoresizingMaskIntoConstraints = false
        let messageTopConstraint:NSLayoutConstraint = NSLayoutConstraint(
            item: messageTableView,
            attribute: NSLayoutAttribute.Top,
            relatedBy: NSLayoutRelation.Equal,
            toItem: chatView,
            attribute: NSLayoutAttribute.Top,
            multiplier: 1.0,
            constant: statusBarFrame.height + HeightNaviBar)
        let messageBottomConstraint:NSLayoutConstraint = NSLayoutConstraint(
            item: messageTableView,
            attribute: NSLayoutAttribute.Bottom,
            relatedBy: NSLayoutRelation.Equal,
            toItem: chatView,
            attribute: NSLayoutAttribute.Bottom,
            multiplier: 1.0,
            constant: (0 – toolbarHeight))
        let messageLeftConstraint:NSLayoutConstraint = NSLayoutConstraint(
            item: messageTableView,
            attribute: NSLayoutAttribute.Left,
            relatedBy: NSLayoutRelation.Equal,
            toItem: chatView,
            attribute: NSLayoutAttribute.Left,
            multiplier: 1.0,
            constant: 0)
        let messageRightConstraint:NSLayoutConstraint = NSLayoutConstraint(
            item: messageTableView,
            attribute: NSLayoutAttribute.Right,
            relatedBy: NSLayoutRelation.Equal,
            toItem: chatView,
            attribute: NSLayoutAttribute.Right,
            multiplier: 1.0,
            constant: 0)
        NSLayoutConstraint.activateConstraints([
            messageTopConstraint,
            messageBottomConstraint,
            messageLeftConstraint,
            messageRightConstraint])

        //add constraints
        inputToolbarView.translatesAutoresizingMaskIntoConstraints = false
        let inputToolbarTopConstraint:NSLayoutConstraint = NSLayoutConstraint(
            item: inputToolbarView,
            attribute: NSLayoutAttribute.Top,
            relatedBy: NSLayoutRelation.Equal,
            toItem: chatView,
            attribute: NSLayoutAttribute.Bottom,
            multiplier: 1.0,
            constant: (0 – toolbarHeight))
        let inputToolbarBottomConstraint:NSLayoutConstraint = NSLayoutConstraint(
            item: inputToolbarView,
            attribute: NSLayoutAttribute.Bottom,
            relatedBy: NSLayoutRelation.Equal,
            toItem: chatView,
            attribute: NSLayoutAttribute.Bottom,
            multiplier: 1.0,
            constant: 0)
        let inputToolbarLeftConstraint:NSLayoutConstraint = NSLayoutConstraint(
            item: inputToolbarView,
            attribute: NSLayoutAttribute.Left,
            relatedBy: NSLayoutRelation.Equal,
            toItem: chatView,
            attribute: NSLayoutAttribute.Left,
            multiplier: 1.0,
            constant: 0)
        let inputToolbarRightConstraint:NSLayoutConstraint = NSLayoutConstraint(
            item: inputToolbarView,
            attribute: NSLayoutAttribute.Right,
            relatedBy: NSLayoutRelation.Equal,
            toItem: chatView,
            attribute: NSLayoutAttribute.Right,
            multiplier: 1.0,
            constant: 0)
        NSLayoutConstraint.activateConstraints([
            inputToolbarTopConstraint,
            inputToolbarBottomConstraint,
            inputToolbarLeftConstraint,

inputToolbarRightConstraint])

虽然可以运行了，但是还是效果不对：

AutoLayout的三种设置方式之——NSLayoutConstraint代码篇 – 愤怒大熊猫 – 博客园

好像是：

父的view，此处的chatView，难道也是不能设置frame？？？

ios – AutoLayout acts strangely when translatesAutoresizingMaskIntoConstraints set to false – Stack Overflow

调试改为：

messageTableView.translatesAutoresizingMaskIntoConstraints = false
// inputMessageToolbar.translatesAutoresizingMaskIntoConstraints = false

// chatView.translatesAutoresizingMaskIntoConstraints = false

出错：

2015-11-29 15:51:54.147 JianDao[51551:2697148] 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)
(
    "<NSAutoresizingMaskLayoutConstraint:0x7f9c8b0a9900 h=–& v=–& UIToolbar:0x7f9c88ee2700.midY ==>",
    "<NSAutoresizingMaskLayoutConstraint:0x7f9c8b0a9970 h=–& v=–& V:[UIToolbar:0x7f9c88ee2700(0)]>",
    "<NSAutoresizingMaskLayoutConstraint:0x7f9c88fe0c10 h=–& v=–& V:[UIView:0x7f9c88eee3c0(603)]>",
    "<NSLayoutConstraint:0x7f9c88efa3f0 UIToolbar:0x7f9c88ee2700.bottom == UIView:0x7f9c88eee3c0.bottom>"
)
Will attempt to recover by breaking constraint
<NSLayoutConstraint:0x7f9c88efa3f0 UIToolbar:0x7f9c88ee2700.bottom == UIView:0x7f9c88eee3c0.bottom>

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.

改为：