html5--留言板案例

时间:2024-03-09 15:16:34
  1 <!DOCTYPE HTML>
  2 <html>
  3     <head>
  4         <meta charset="gb2312">
  5         <title>HTML5--JS API-本地存储 Web留言板</title>
  6         <style type="text/css">
  7         *{margin:0; padding:0;}
  8         body,input{font-size:14px; line-height:24px; color:#333; font-family:Microsoft yahei, Song, Arial, Helvetica, Tahoma, Geneva;}
  9         h1{margin-bottom:15px; height:100px; line-height:100px; text-align:center; font-size:24px; color:#fff; background:#0051a1;}
 10         #content #post,#comment p{zoom:1;}
 11         #content #post:after,#comment p:after{display:block; height:0; clear:both; visibility:hidden; overflow:hidden; content:\'.\';}
 12         .transition{-webkit-transition:all 0.5s linear; -moz-transition:all 0.5s linear; -o-transition:all 0.5s linear; -ms-transition:all 0.5s linear; transition:all 0.5s linear;}
 13         #content{margin:0 auto; width:960px; overflow:hidden;}
 14         #content #post{margin-bottom:15px; padding-bottom:15px; border-bottom:1px #d4d4d4 dashed;}
 15         #content #post textarea{display:block; margin-bottom:10px; padding:5px; width:948px; height:390px; border:1px #d1d1d1 solid; border-radius:5px; resize:none; outline:none;}
 16         #content #post textarea:hover{border:1px #9bdf70 solid; background:#f0fbeb;}
 17         #content #post #postBt,#content #post #clearBt{margin-left:5px; padding:3px; float:right;}
 18         #comment{overflow:hidden;}
 19         #comment p{margin-bottom:10px; padding:10px; border-radius:5px;}
 20         #comment p:nth-child(odd){border:1px solid #e3e197; background:#ffd;}
 21         #comment p:nth-child(even){border:1px solid #adcd3c; background:#f2fddb;}
 22         #comment p span{display:inline; float:left;}
 23         #comment p .msg{width:738px;}
 24         #comment p .datetime{width:200px; color:#999; text-align:right;}
 25         </style>
 26         <script type="text/javascript">
 27         var Storage =
 28         {
 29             saveData:function()//保存数据
 30             {
 31                 var data = document.querySelector("#post textarea");
 32                 if(data.value != "")
 33                 {
 34                     var time = new Date().getTime() + Math.random() * 5;//getTime是Date对象中的方法,作用是返回 1970年01月01日至今的毫秒数
 35                     localStorage.setItem(time, data.value + "|" + this.getDateTime());//将毫秒数存入Key值中,可以降低Key值重复率
 36                     data.value = "";
 37                     this.writeData();
 38                 }
 39                 else
 40                 {
 41                     alert("请填写您的留言!");
 42                 }
 43             },
 44             writeData:function()//输出数据
 45             {
 46                 var dataHtml = "", data = "";
 47                 for(var i = localStorage.length-1; i >= 0; i--)//效率更高的循环方法
 48                 {
 49                     data = localStorage.getItem(localStorage.key(i)).split("|");
 50                     dataHtml += "<p><span class=\"msg\">" + data[0] + "</span><span class=\"datetime\">" + data[1] + "</span></p>";
 51                 }
 52                 document.getElementById("comment").innerHTML = dataHtml;
 53             },
 54             clearData:function()//清空数据
 55             {
 56                 if(localStorage.length > 0)
 57                 {
 58                     if(window.confirm("清空后不可恢复,是否确认清空?"))
 59                     {
 60                         localStorage.clear();
 61                         this.writeData();
 62                     }
 63                 }
 64                 else
 65                 {
 66                     alert("没有需要清空的数据!");
 67                 }
 68             },
 69             getDateTime:function()//获取日期时间,例如 2012-03-08 12:58:58
 70             {
 71                 var isZero = function(num)//私有方法,自动补零
 72                 {
 73                     if(num < 10)
 74                     {
 75                         num = "0" + num;
 76                     }
 77                     return num;
 78                 }
 79                 
 80                 var d = new Date();
 81                 return d.getFullYear() + "-" + isZero(d.getMonth() + 1) + "-" + isZero(d.getDate()) + " " + isZero(d.getHours()) + ":" + isZero(d.getMinutes()) + ":" + isZero(d.getSeconds());
 82             }            
 83         }
 84         
 85         window.onload = function()
 86         {
 87             Storage.writeData();//当打开页面的时候,先将localStorage中的数据输出一边,如果没有数据,则输出空
 88             document.getElementById("postBt").onclick = function(){Storage.saveData();}//发表评论按钮添加点击事件,作用是将localStorage中的数据输出
 89             document.getElementById("clearBt").onclick = function(){Storage.clearData();}//清空所有已保存的数据
 90         }
 91         </script>
 92     </head>
 93     
 94     <body>
 95         <h1>HTML5--JS API-本地存储 Web留言板</h1>
 96         <div id="content">
 97             <div id="post">
 98                 <textarea class="transition"></textarea>
 99                 <input id="postBt" type="button" value="发表评论"/>
100                 <input id="clearBt" type="button" value="清空所有已保存的数据"/>
101             </div>
102             <div id="comment"></div>
103         </div>
104     </body>
105 </html>