無法使第二個事件偵聽器為 MVC 計數器應用程序工作

Question

我正在嘗試使用 MVC 方法創建一個簡單的計數器應用程序，但我無法弄清楚為什么向下計數器的事件偵聽器不起作用但向上計數器起作用。 必須有一些我忽略的東西，但我對這種方法完全陌生。 任何幫助將不勝感激。

//model 
var model = 
      {
        clickCount: 0
      };


//controller 

  var controller = {

      init: function() { 
           view.init();
      },
      incrementCounterUp: function() {
        counter.textContent = model.clickCount += 1;
      },
      incrementCounterDown: function() {
        counter.textContent = model.clickCount -= 1;
      }
  };


//view 
var counter = document.createElement('p');
counter.textContent = (model.clickCount);
counter.id = counter;
document.body.appendChild(counter);

var upButton = document.createElement("button");
upButton.id = upButton;
document.body.appendChild(upButton);

var upButtonText = document.createTextNode("Up");
upButtonText.id = upButtonText;
upButton.appendChild(upButtonText);

var downButton = document.createElement("button");
downButton.id = downButton;
document.body.appendChild(downButton);

var downButtonText = document.createTextNode("Down");
downButtonText.id = downButtonText;
downButton.appendChild(downButtonText);



var view = {
    init: function() {
    // store pointers to our DOM elements for easy access 
      this.counterElem = document.getElementById(counter);
      this.upButtonElem = document.getElementById(upButton);
      this.upButtonElem.addEventListener('click', function(){
          controller.incrementCounterUp();
      });

      this.downButtonElem = document.getElementById(downButton);
      this.downButtonElem.addEventListener('click', function(){
          controller.incrementCounterDown();
      });
    }
};


controller.init();

Answer 1

contoller.incrementCounterDown();

你拼錯了“控制器”。 :P

Answer 2

 //model 
var model = 
      {
        clickCount: 0
      };


//controller 

  var controller = {

      init: function() { 
           view.init();
      },
      incrementCounterUp: function() {
        model.clickCount += 1
        view.render()
      },
      incrementCounterDown: function() {
        model.clickCount -= 1
        view.render()
      }
  };


//view 
var counter = document.createElement('p');
counter.textContent = (model.clickCount);
counter.id = 'counter';
document.body.appendChild(counter);

var upButton = document.createElement("button");
upButton.textContent = 'Up'
upButton.id = 'upButton';
document.body.appendChild(upButton);

var downButton = document.createElement("button");
downButton.textContent = 'Down';
downButton.id = 'downButton';
document.body.appendChild(downButton);


var view = {
    init: function() {
    // store pointers to our DOM elements for easy access 
      this.upButtonElem = document.getElementById('upButton')
      this.downButtonElem = document.getElementById('downButton')

      this.downButtonElem.addEventListener('click', function(){
          controller.incrementCounterDown()
      })
      this.upButtonElem.addEventListener('click', function(){
          controller.incrementCounterUp()
      })
    },
    render: function() {
      this.counterElem = document.getElementById('counter')
      this.counterElem.textContent = model.clickCount
    }
};




controller.init();