AutoLayout - 无法同时满足 swift5 中的约束

Question

当您按下 web 视图侧边栏上的按钮时，会出现我的问题。 该按钮向 web 视图发送一条简单消息并复制剪贴板。 Swift 将收到的消息显示为敬酒。 这很简单。

function似乎没有问题，

但用户界面是个问题。 按下按钮时，屏幕从上到下滑动，显示吐司，再次按下按钮会激活按下侧边栏上另一个按钮的 function。

屏幕是一样的，但屏幕似乎是向下的。 侧边栏屏幕包含一个滚动条。 这就是它的意思吗？

错误日志：

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:0x283a866c0 h=-&- v=-&- _UIToolbarContentView:0x133ebf3b0.width == UIToolbar:0x133ebef70.width   (active)>",
    "<NSLayoutConstraint:0x283a8b390 H:|-(0)-[_UIButtonBarStackView:0x133ec0570]   (active, names: '|':_UIToolbarContentView:0x133ebf3b0 )>",
    "<NSLayoutConstraint:0x283a8b3e0 _UIButtonBarStackView:0x133ec0570.trailing == _UIToolbarContentView:0x133ebf3b0.trailing   (active)>",
    "<NSLayoutConstraint:0x283a84910 H:|-(16)-[_UIModernBarButton:0x133dcc420]   (active, names: '|':_UIButtonBarButton:0x133dcc1d0 )>",
    "<NSLayoutConstraint:0x283a84960 H:[_UIModernBarButton:0x133dcc420]-(>=8)-|   (active, names: '|':_UIButtonBarButton:0x133dcc1d0 )>",
    "<NSLayoutConstraint:0x283a84f50 H:|-(>=5)-[_UIModernBarButton:0x133ecbe60]   (active, names: '|':_UIButtonBarButton:0x133ecbc10 )>",
    "<NSLayoutConstraint:0x283a84fa0 H:[_UIModernBarButton:0x133ecbe60]-(>=5)-|   (active, names: '|':_UIButtonBarButton:0x133ecbc10 )>",
    "<NSLayoutConstraint:0x283a856d0 H:|-(8)-[_UIModernBarButton:0x133dcd540'Done']   (active, names: '|':_UIButtonBarButton:0x133ecc380 )>",
    "<NSLayoutConstraint:0x283a85720 H:[_UIModernBarButton:0x133dcd540'Done']-(16)-|   (active, names: '|':_UIButtonBarButton:0x133ecc380 )>",
    "<NSLayoutConstraint:0x283a85ae0 'UISV-canvas-connection' UILayoutGuide:0x2820c1c00'UIViewLayoutMarginsGuide'.leading == _UIButtonBarButton:0x133dcc1d0.leading   (active)>",
    "<NSLayoutConstraint:0x283a85cc0 'UISV-canvas-connection' UILayoutGuide:0x2820c1c00'UIViewLayoutMarginsGuide'.trailing == _UIButtonBarButton:0x133ecc380.trailing   (active)>",
    "<NSLayoutConstraint:0x283a85d10 'UISV-spacing' H:[_UIButtonBarButton:0x133dcc1d0]-(0)-[UIView:0x133e94d90]   (active)>",
    "<NSLayoutConstraint:0x283a85d60 'UISV-spacing' H:[UIView:0x133e94d90]-(0)-[_UIButtonBarButton:0x133ecbc10]   (active)>",
    "<NSLayoutConstraint:0x283a85db0 'UISV-spacing' H:[_UIButtonBarButton:0x133ecbc10]-(0)-[UIView:0x133ecc1a0]   (active)>",
    "<NSLayoutConstraint:0x283a85e00 'UISV-spacing' H:[UIView:0x133ecc1a0]-(0)-[_UIButtonBarButton:0x133ecc380]   (active)>",
    "<NSLayoutConstraint:0x283a835c0 'UIView-Encapsulated-Layout-Width' UIToolbar:0x133ebef70.width == 0   (active)>",
    "<NSLayoutConstraint:0x283a8b250 'UIView-leftMargin-guide-constraint' H:|-(0)-[UILayoutGuide:0x2820c1c00'UIViewLayoutMarginsGuide'](LTR)   (active, names: '|':_UIButtonBarStackView:0x133ec0570 )>",
    "<NSLayoutConstraint:0x283a8b2f0 'UIView-rightMargin-guide-constraint' H:[UILayoutGuide:0x2820c1c00'UIViewLayoutMarginsGuide']-(0)-|(LTR)   (active, names: '|':_UIButtonBarStackView:0x133ec0570 )>"
)

Will attempt to recover by breaking constraint 
<NSLayoutConstraint:0x283a84960 H:[_UIModernBarButton:0x133dcc420]-(>=8)-|   (active, names: '|':_UIButtonBarButton:0x133dcc1d0 )>

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

我真的很想解决这个问题。

编辑

---

找到了问题的原因。 按下按钮将弹出键盘并再次消失。 为什么会这样？

这个按钮的function和我通讯。 巴顿让我给他看一条祝酒词。

JS函数

function copy_address(){
      var t = document.createElement("textarea");
      document.body.appendChild(t);
      t.value = $("#text").val();
      t.select();
      document.execCommand('copy');
      document.body.removeChild(t);
      var postData = {
                tip: "testing",
                message: "sucess",
                timestamp: (new Date()).getTime().toString()
        };
        webkit.messageHandlers.send.postMessage(postData);
}

JSP 按钮视图

<div class="w" id="user"></div>
<div class="b-copy">
    <button type="button" class="btn" onclick="copy_address()">copy</button>
    <input type="text" id="copy_text" style="display: none;">
</div>

WebViewController 中的 Swift 代码

import Toaster
...
    override func loadView() {
        super.loadView()
      ...
        mainWebView = WKWebView(frame: mainWebView.frame, configuration: config)

        mainWebView.uiDelegate = self
        mainWebView.navigationDelegate = self

        view.addSubview(mainWebView)
        view.addSubview(indicatorImage)
}
    @available(iOS 8.0, *)
    func userContentController(_ userContentController: WKUserContentController, didReceive message: WKScriptMessage) {
        if message.name == "message" {
            let sendmessage = message.body as! NSDictionary
            guard sendmessage["val"] != nil else {
                return
            }
            let val : String = sendmessage["val"] as! String
            if sendmessage["val2"] != nil {
                getmessage = sendmessage["val2"] as? String
            }
          switch val {
            case "testing":
                Toast(text: getmessage).show()
                break
        ....
}
}

Answer 1

我通过模拟器发现了这个问题。

当我用我的实际 iPhone 进行检查时，由于我看不到键盘，屏幕看起来像是从上到下往下掉的，但实际上只是看了一小会然后就消失了。

这就是工具栏高度有问题的原因。 键盘问题的原因是JS function。

t.select(); 
document.execCommand('copy');

由于这部分，键盘可见并消失了。 所以我通过搜索解决了这个问题。

t.readOnly = true;

我通过添加此代码解决了我的问题。