更新

Question

我有这些javascript文件。了解MVC如何与javascript结合使用，这确实是一个很小的测试项目。当我尝试单击“删除Bloak”按钮时，除了ID为100的最后一个按钮外，什么都没有发生。其他按钮没有任何单击事件。为什么？

Controller.js

{
switch (GetChar ())
{
  case Ping:
    Serial.write ("Connection estabilished.\n");
    continue;

  case PANAngle:
  {
    int h=0;
    h = GetChar ();
    if(h >= '0' && h <= '9')              // is h a number?  
    pos = pos * 10 + h - '0';              // yes, accumulate the value

    else if(h == 'p')  // pan
    {
      panServo.write(pos);          
      Serial.print("Pan Servo angle: "); 
      Serial.println(pos); 
    }
  }
 case TILTAngle:
  {
  int j=0;  
  j = GetChar ();
  if(j >= '0' && j <= '9')              // is j a number?  
  pos = pos * 10 + j - '0';           // yes, accumulate the value
  else if(j == 't')  // tilt
    {
      tiltServo.write(pos);          
      Serial.print("Tilt Servo angle: "); 
      Serial.println(pos); 
    }
  }

Model.js

    var BloakController = function BloakController(model, view) {
    this.model = model;
    this.view = view;
}

BloakController.prototype.init = function init() {
    this.view.onAddBloak = this.addBloak.bind(this);

    this.view.onDeleteBloak = this.deleteBloak.bind(this);

    this.view.onGetAllBloaks = this.getAllBloaks.bind(this);
}

BloakController.prototype.addBloak = function addBloak() {

}

BloakController.prototype.getAllBloaks = function getAllBloaks() {
    this.model.getAllBloaks(this.getAllBloaksList.bind(this));
}

BloakController.prototype.getAllBloaksList = function getAllBloaksList(allBloaksList) {
    for (var i = 0; i < allBloaksList.length; i++) {
        var bloak = allBloaksList[i];
        var bloakDataObjectModel = {
            title: bloak.title,
            body: bloak.body,
            userId: bloak.userId,
            id: bloak.id
        };

        this.view.render(bloakDataObjectModel);
    }
}

BloakController.prototype.deleteBloak = function deleteBloak(id) {
    this.model.deleteBloak(id, this.getAllBloaksList.bind(this));
}

View.js

var BloakModel = function BloakModel(XMLHttpRequest) {
    this.XMLHttpRequest = XMLHttpRequest;
}

BloakController.prototype.addBloak = function addBloak() {

}

BloakModel.prototype.getAllBloaks = function getAllBloaks(callback) {
    var request = new this.XMLHttpRequest;

    request.onload = function onLoad(e) {
        var ajaxResponse = JSON.parse(e.currentTarget.responseText);
        callback(ajaxResponse);
    }

    request.open('GET', 'https://jsonplaceholder.typicode.com/posts', true);
    request.send();
}

BloakModel.prototype.deleteBloak = function deleteBloak(id, callback) {
    console.log(id);
    var request = new this.XMLHttpRequest;

    request.onload = function onLoad(e) {
        var ajaxResponse = JSON.parse(e.currentTarget.responseText);
        callback(ajaxResponse);
    }

    request.open('DELETE', 'https://jsonplaceholder.typicode.com/posts/' + id, true);
    request.send();
}

App.js

var BloakView = function BloakView(domElement) {
    this.domElement = domElement;

    this.onAddBloak = null;
    this.onDeleteBloak = null;
    this.onGetAllBloaks = null;
}

BloakView.prototype.render = function render(bloakDataObjectModel) {
    this.domElement.innerHTML += '<div class="bloakContainer"><h3>' + bloakDataObjectModel.title + '</h3><p class="bloakContent">' + bloakDataObjectModel.body + '</p><label class="bloakAuthor">' + bloakDataObjectModel.userId + '</label><br /><label class="bloakDate">' + bloakDataObjectModel.id + '</label><br /><input id=' + bloakDataObjectModel.id + ' type="button" value="Delete Bloak" /></div>';

    var addBloakButton = document.getElementById('addBloakButton');

    var deleteBloakButton = document.getElementById(bloakDataObjectModel.id);

    addBloakButton.addEventListener('click', this.onAddBloak);

    deleteBloakButton.addEventListener('click', this.onDeleteBloak);
}

Answer 1

更新

事实证明，做完更多研究后，我完全错了，好像使用innerHTML属性会导致所有子元素read more about it here遭到破坏。无论哪种方式，提供的解决方案仍然有效，事实证明我自己并不知道。

我的大脑屁

我本应该意识到我最初是错的，如果我是对的，那么您将出现一个错误，指出您无法将事件监听器附加到null或undefined上，这很糟糕，我这是愚蠢的错误！

想法

非常简短查看了您的代码，我认为可以肯定地说您的渲染功能有些错误，由于使用了innerHTML，它无法以足够快的速度解析更新的HTML事件监听器可以正常工作...

我自己进行了测试，并完成了以下操作：

setTimeout(() => {
    var addBloakButton = document.getElementById('addBloakButton');
    var deleteBloakButton = document.getElementById(bloakDataObjectModel.id);
    addBloakButton.addEventListener('click', this.onAddBloak);
    deleteBloakButton.addEventListener('click', this.onDeleteBloak);
}, 10);

有效。因此，如果您不想做太大的更改，则可以做我上面所做的事情，或者，可以按照以下方式做点事情：

  var div = document.createElement("div");
  div.innerHTML = '<div class="bloakContainer"><h3>' + bloakDataObjectModel.title + '</h3><p class="bloakContent">' + bloakDataObjectModel.body + '</p><label class="bloakAuthor">' + bloakDataObjectModel.userId + '</label><br /><label class="bloakDate">' + bloakDataObjectModel.id + '</label><br /><input id=' + bloakDataObjectModel.id + ' type="button" value="Delete Bloak" /></div>';
  this.domElement.append(div);

  var addBloakButton = document.getElementById('addBloakButton');
  var deleteBloakButton = div.querySelector('input[id*="' + bloakDataObjectModel.id + '"]');
  addBloakButton.addEventListener('click', this.onAddBloak);
  deleteBloakButton.addEventListener('click', this.onDeleteBloak);

此外，作为一种更可靠，更可靠的方法，我将在视图中实现一个onRender函数，基本上说一次和一次 > 所有相关HTML已呈现，然后启动onRender方法。或者，也许像view.dispatchEvents之类的东西，等等。特别是在此示例中，我将在控制器中运行这样的功能，因此一旦getAllBloaksList呈现了所有相关的数据，您可以然后启动dispatchEvents函数，如下所示：

// Within the controller part... 
BloakController.prototype.getAllBloaksList = function getAllBloaksList(allBloaksList) {
  for (var i = 0; i < allBloaksList.length; i++) {
    var bloak = allBloaksList[i];
    var bloakDataObjectModel = {
      title: bloak.title,
      body: bloak.body,
      userId: bloak.userId,
      id: bloak.id
    };

    this.view.render(bloakDataObjectModel);
  }

  this.view.dispatchEvents();
};


// .. Within the View part...
BloakView.prototype.dispatchEvents = function () {
  var list = this.domElement.querySelectorAll(".bloakContainer");
  var todo = this.onDeleteBloak;

  list.forEach(function (div) {
    var deleteButton = div.querySelector("input[type=button]");

    deleteButton.onclick =  function () {
      todo(this.id);
    };
  });
};

演示

// Controller.
var BloakController = function BloakController(model, view) {
  this.model = model;
  this.view = view;
};

BloakController.prototype.init = function init() {
  this.view.onAddBloak = this.addBloak.bind(this);
  this.view.onDeleteBloak = this.deleteBloak.bind(this);
  this.view.onGetAllBloaks = this.getAllBloaks.bind(this);
};

BloakController.prototype.addBloak = function addBloak() {
  // todo
};

BloakController.prototype.getAllBloaks = function getAllBloaks() {
  this.model.getAllBloaks(this.getAllBloaksList.bind(this));
};

BloakController.prototype.getAllBloaksList = function getAllBloaksList(allBloaksList) {
  for (var i = 0; i < allBloaksList.length; i++) {
    var bloak = allBloaksList[i];
    var bloakDataObjectModel = {
      title: bloak.title,
      body: bloak.body,
      userId: bloak.userId,
      id: bloak.id
    };
    this.view.render(bloakDataObjectModel);
  }
  this.view.dispatchEvents();
};

BloakController.prototype.deleteBloak = function deleteBloak(id) {
  this.model.deleteBloak(id, this.getAllBloaksList.bind(this));
};


// Model.
var BloakModel = function BloakModel(XMLHttpRequest) {
  this.XMLHttpRequest = XMLHttpRequest;
};

BloakController.prototype.addBloak = function addBloak() {
  // todo
};

BloakModel.prototype.getAllBloaks = function getAllBloaks(callback) {
  var request = new this.XMLHttpRequest;
  request.onload = function onLoad(e) {
    var ajaxResponse = JSON.parse(e.currentTarget.responseText);
    callback(ajaxResponse);
  }
  request.open('GET', 'https://jsonplaceholder.typicode.com/posts', true);
  request.send();
};

BloakModel.prototype.deleteBloak = function deleteBloak(id, callback) {
  console.log(id);
  var request = new this.XMLHttpRequest;
  request.onload = function onLoad(e) {
    var ajaxResponse = JSON.parse(e.currentTarget.responseText);
    callback(ajaxResponse);
  }
  request.open('DELETE', 'https://jsonplaceholder.typicode.com/posts/' + id, true);
  request.send();
};


// View. 
var BloakView = function BloakView(domElement) {
  this.domElement = domElement;
  this.onAddBloak = null;
  this.onDeleteBloak = null;
  this.onGetAllBloaks = null;
};

BloakView.prototype.render = function render(bloakDataObjectModel) {
  this.domElement.innerHTML += '<div class="bloakContainer"><h3>' + bloakDataObjectModel.title + '</h3><p class="bloakContent">' + bloakDataObjectModel.body + '</p><label class="bloakAuthor">' + bloakDataObjectModel.userId + '</label><br /><label class="bloakDate">' + bloakDataObjectModel.id + '</label><br /><input id=' + bloakDataObjectModel.id + ' type="button" value="Delete Bloak" /></div>';
}

BloakView.prototype.dispatchEvents = function() {
  var list = this.domElement.querySelectorAll(".bloakContainer");
  var todo = this.onDeleteBloak;
  var addBloakButton = document.getElementById('addBloakButton');
  addBloakButton.addEventListener('click', this.onAddBloak);

  list.forEach(function(div) {
    var deleteButton = div.querySelector("input[type=button]");
    deleteButton.onclick = function() {
      todo(this.id);
    };
  });
};


// App.
var bloakModel = new BloakModel(XMLHttpRequest);
var targetElement = document.getElementById('bloaksContainer');
var bloakView = new BloakView(targetElement);
var bloakController = new BloakController(bloakModel, bloakView);

bloakController.init();
bloakController.getAllBloaks();

<button id="addBloakButton">Add</button>
<div id="bloaksContainer">
  <!-- DHTML -->
</div>

Answer 2

代码this.domElement.innerHTML += ...;不正确。您正在使用+ =运算符，该运算符会自身添加一些内容，然后分配新值。

新值是现有innerHTML和新HTML的结果。因此，新值[HTML]将没有以前添加的事件处理程序，它将仅复制HTML。

您可以使用appendChild方法来添加新元素。

此外，您应该避免将for-loop与innerHTML一起使用，因为它将不断更新DOM，并且您可能会在屏幕上看到闪烁。如果必须使用innerHTML，则应该

一起创建整个HTML [innerHTML]，然后立即注入
然后使用事件委托添加事件处理程序。

事件委托是一种将事件绑定到顶级容器的技术，因此您不必担心将事件侦听器附加到每个项目。

您可以阅读有关DOM here的更多信息。

Javascript MVC，addEventListener不能附加到dom元素

2 个答案:

更新

我的大脑屁

想法

演示