在进入页面时显示一次警告框

Question

我这里有一个代码，每次页面重新加载一个警告将弹出。但我希望警报框能弹出一次。例如，每当我打开那个页面时，都会弹出一个警告框，但如果我重新加载那个页面，就不会弹出任何警告框。有人知道我怎么做吗?

下面是我的警告框代码:

<script type="text/javascript">
    window.onload = function () { 
    alert("Sending of SMS is scheduled TODAY!");
    //dom not only ready, but everything is loaded
    }
</script>

提前感谢您的帮助

Answer 1

按如下操作:

<script type="text/javascript">
    var dateObj = new Date();
    var month = dateObj.getUTCMonth() + 1; //months from 1-12
    var day = dateObj.getUTCDate();
    var year = dateObj.getUTCFullYear();
    var today = year + "/" + month + "/" + day;
    window.onload = function () { 
          var item = localStorage.getItem("alertShown_"+today);
          if ( item === null || item != "Yes") { 
          //check if localStorage has value or it is == "Yes"
                 alert("Sending of SMS is scheduled TODAY!");
                 localStorage.setItem("alertShown_"+today,"Yes"); //set some value for future check
          }
    }
</script>