JS手写兼容性事件绑定

class bindEvent {
    
  constructor (element) {
    
    this.element = element
  }
  // 绑定
  addEventListener (type, handler) {
    
    if (this.element.addEventListener) {
    
      this.element.addEventListener(type, handler, false)
    } else if (this.element.attachEvent) {
    
      this.element.attachEvent('on'+type, handler, false)
    } else {
    
      this.element['on'+type] = handler
    }
  }
  // 解绑
  removeEventListener (type, handler) {
    
    if (this.element.removeEventListener) {
    
      this.element.removeEventListener(type, handler, false)
    } else if (this.element.detachEvent) {
    
      this.element.detachEvent('on'+type, handler, false)
    } else {
    
      this.element['on'+type] = null
    }
  }
  // 阻断
  static stopPropogation (e) {
    
    if (e.stopPropogation) {
    
      e.stopPropogation
    } else {
    
      e.cancelBubble = true
    }
  }
  // 默认拦截
  static preventDefault (e) {
    
    if (e.preventDefault) {
    
      e.preventDefault
    } else {
    
      e.returnValue = false
    }
  }
}