javascript - 无法使第二个事件监听器适用于 MVC 计数器应用程序

Question

我正在尝试使用 MVC 方法创建一个简单的计数器应用程序，但我无法弄清楚为什么向下计数器的事件监听器不起作用，但向上计数器却起作用。肯定有一些我忽略的东西，但我对这种方法完全陌生。任何帮助将不胜感激。

//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();

您拼错了“ Controller ”。 :P