禁止蒙层底部页面跟随滚动

	
 
	
 
	
 
	
	



	
 
		
  
		
  
		
  
		
  
		
  
		
  
   打开弹窗
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
		
  
	
 
	
 
		
   
   关闭弹窗 
  
	
 
	
	




// ./stopBodyScroll.js 

let _stopBodyScroll = {
	options: {
		bodyEl: document.body,
		topIndex: 0
	},
	init: function(isFixed) {
		if (isFixed) {
			this.options.topIndex = window.scrollY
			this.options.bodyEl.style.position = 'fixed'
			this.options.bodyEl.style.top = -this.options.topIndex + 'px'
		} else {
			this.options.bodyEl.style.position = ''
			this.options.bodyEl.style.top = ''
			window.scrollTo(0, this.options.topIndex) // 回到原先的top
		}
	}
}