javascript的几个重要小demo

  • 跑马灯：

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>欢迎领导莅临指导！</title>
    <script type="text/javascript">
        function Go(){
        var content = document.title;
        var firstChar = content.charAt(0);
        var sub =content.substring(1, content.length);
        document.title = sub + firstChar;
        }

        setInterval('Go()', 1000);

    </script>
</head>
<body>


</body>
</html>
View Code
  • 搜索框：
 1 <!DOCTYPE html>
 2 <html lang="en">
 3 <head>
 4     <meta charset="UTF-8">
 5     <title></title>
 6     <style>
 7         .gray{
 8         color:gray;
 9         }
10         .black{
11         color: black;
12         }
13     </style>
14     <script type="text/javascript">
15         function Enter(){
16         var id = document.getElementById("tip");
17         id.className = 'black';
18         if(id,value == "请输入关键字"||id.value.trim() =='')){
19         id.value = ''
20 
21           }
22          }
23         function Leave(){
24          var id = document.getElementById("tip");
25          var val = id.value;
26          if (val.length == 0||id.value.trin() ==""){
27          id.value = "请输入关键字"
28          id.className= 'gray';
29          }else{
30          id.className = 'black';
31          }
32         }
33 
34     </script>
35 </head>
36 <body>
37 <input type = 'text' class="gray" id="tip" value="请输入关键字"onfocus='Enter();'  onblur='Leave();'/>
38 
39 
40 </body>
41 </html>
View Code

  • 滚动菜单：

 

  1 <!DOCTYPE html>
  2 <html>
  3 <head lang="en">
  4     <meta charset="UTF-8">
  5     <title></title>
  6 </head>
  7 <style>
  8 
  9     body{
 10         margin: 0px auto;
 11     }
 12     img {
 13         border: 0;
 14     }
 15     ul{
 16         padding: 0;
 17         margin: 0;
 18         list-style: none;
 19     }
 20     h1{
 21         padding: 0;
 22         margin: 0;
 23     }
 24     .clearfix:after {
 25         content: ".";
 26         display: block;
 27         height: 0;
 28         clear: both;
 29         visibility: hidden;
 30     }
 31 
 32     .wrap{
 33         width: 980px;
 34         margin: 0 auto;
 35     }
 36 
 37     .pg-header{
 38         background-color: #303a40;
 39         -webkit-box-shadow: 0 2px 5px rgba(0,0,0,.2);
 40         -moz-box-shadow: 0 2px 5px rgba(0,0,0,.2);
 41         box-shadow: 0 2px 5px rgba(0,0,0,.2);
 42     }
 43     .pg-header .logo{
 44         float: left;
 45         padding:5px 10px 5px 0px;
 46     }
 47     .pg-header .logo img{
 48         vertical-align: middle;
 49         width: 110px;
 50         height: 40px;
 51 
 52     }
 53     .pg-header .nav{
 54         line-height: 50px;
 55     }
 56     .pg-header .nav ul li{
 57         float: left;
 58     }
 59     .pg-header .nav ul li a{
 60         display: block;
 61         color: #ccc;
 62         padding: 0 20px;
 63         text-decoration: none;
 64         font-size: 14px;
 65     }
 66     .pg-header .nav ul li a:hover{
 67         color: #fff;
 68         background-color: #425a66;
 69     }
 70     .pg-body{
 71 
 72     }
 73     .pg-body .catalog{
 74         position: absolute;
 75         top:60px;
 76         width: 200px;
 77         background-color: #fafafa;
 78         bottom: 0px;
 79     }
 80     .pg-body .catalog.fixed{
 81         position: fixed;
 82         top:10px;
 83     }
 84 
 85     .pg-body .catalog .catalog-item.active{
 86         color: #fff;
 87         background-color: #425a66;
 88     }
 89 
 90     .pg-body .content{
 91         position: absolute;
 92         top:60px;
 93         width: 700px;
 94         margin-left: 210px;
 95         background-color: #fafafa;
 96         overflow: auto;
 97     }
 98     .pg-body .content .section{
 99         height: 500px;
100         border: 1px solid red;
101     }
102 </style>
103 
104 <body onscroll="ScrollEvent();">
105 <div class="pg-header">
106     <div class="wrap clearfix">
107         <div class="logo">
108             <a href="#">
109                 <img src="http://core.pc.lietou-static.com/revs/images/common/logo_7012c4a4.pn">
110             </a>
111         </div>
112         <div class="nav">
113             <ul>
114                 <li>
115                     <a  href="#">NO</a>
116                 </li>
117                 <li>
118                     <a  href="#">NO1</a>
119                 </li>
120                 <li>
121                     <a  href="#">NO2</a>
122                 </li>
123             </ul>
124         </div>
125 
126     </div>
127 </div>
128 <div class="pg-body">
129     <div class="wrap">
130         <div class="catalog" id="catalog">
131             <div class="catalog-item" auto-to="function1"><a>第1章</a></div>
132             <div class="catalog-item" auto-to="function2"><a>第2章</a></div>
133             <div class="catalog-item" auto-to="function3"><a>第3章</a></div>
134         </div>
135         <div class="content" id="content">
136             <div menu="function1" class="section">
137                 <h1>开始</h1>
138             </div>
139             <div menu="function2" class="section">
140                 <h1>高潮</h1>
141             </div>
142             <div menu="function3" class="section" style="height: 200px;">
143                 <h1>结束</h1>
144             </div>
145         </div>
146     </div>
147 
148 </div>
149     <script>
150         function ScrollEvent(){
151             var bodyScrollTop = document.body.scrollTop;
152             if(bodyScrollTop>50){
153                 document.getElementsByClassName('catalog')[0].classList.add('fixed');
154             }else{
155                 document.getElementsByClassName('catalog')[0].classList.remove('fixed');
156             }
157 
158             var content = document.getElementById('content');
159             var sections = content.children;
160             for(var i=0;i<sections.length;i++){
161                 var current_section = sections[i];
162 
163                 // 当前标签距离顶部绝对高度
164                 var scOffTop = current_section.offsetTop + 60;
165 
166                 // 当前标签距离顶部，相对高度
167                 var offTop = scOffTop - bodyScrollTop;
168 
169                 // 当前标签高度
170                 var height = current_section.scrollHeight;
171 
172                 if(offTop<0 && -offTop < height){
173                     // 当前标签添加active
174                     // 其他移除 active
175 
176                     // 如果已经到底部，现实第三个菜单
177                     // 文档高度 ＝ 滚动高度 + 视口高度
178 
179                     var a = document.getElementsByClassName('content')[0].offsetHeight + 60;
180                     var b = bodyScrollTop + document.documentElement.clientHeight;
181                     console.log(a+60,b);
182                     if(a == b){
183                         var menus = document.getElementById('catalog').children;
184                         var current_menu = document.getElementById('catalog').lastElementChild;
185                         current_menu.classList.add('active');
186                         for(var j=0;j<menus.length;j++){
187                             if(menus[j] == current_menu){
188 
189                             }else{
190                                 menus[j].classList.remove('active');
191                             }
192                         }
193                     }else{
194                         var menus = document.getElementById('catalog').children;
195                         var current_menu = menus[i];
196                         current_menu.classList.add('active');
197                         for(var j=0;j<menus.length;j++){
198                             if(menus[j] == current_menu){
199 
200                             }else{
201                                 menus[j].classList.remove('active');
202                             }
203                         }
204                     }
205 
206 
207 
208 
209                     break;
210                 }
211 
212             }
213 
214 
215         }
216     </script>
217 </body>
218 </html>
View Code

  • 搜索框的五毛特效：

 1    <input onfocus="Focus(this);" onblur="Blur(this);" id="search" value="请输入关键字" style="color: gray;" />
 2 
 3     <script>
 4         function Focus(ths){
 5             ths.style.color = "black";
 6             if(ths.value == '请输入关键字' || ths.value.trim() == ""){
 7 
 8                 ths.value = "";
 9             }
10         }
11 
12         function Blur(ths){
13             if(ths.value.trim() == ""){
14                 ths.value = '请输入关键字';
15                 ths.style.color = 'gray';
16             }else{
17                 ths.style.color = "black";
18             }
19         }
20     </script>
View Code

  • 全选、反选和取消：

<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title></title>
</head>
<body>
    <input type="button" value="全选"  onclick="CheckAll();"/>
    <input type="button" value="取消" onclick="CancelAll();"/>
    <input type="button" value="反选" onclick="ReverseCheck();"/>

    <table border="1" >
        <thead>

        </thead>
        <tbody id="tb">
            <tr>
                <td><input type="checkbox" /></td>
                <td>1</td>
                <td>2</td>
            </tr>
            <tr>
                <td><input type="checkbox" /></td>
                <td>1</td>
                <td>2</td>
            </tr>
            <tr>
                <td><input type="checkbox" /></td>
                <td>1</td>
                <td>2</td>
            </tr>
            <tr>
                <td><input type="checkbox" /></td>
                <td>1</td>
                <td>2</td>
            </tr>
        </tbody>
    </table>
    <script>
        function CheckAll(ths){
            var tb = document.getElementById('tb');
            var trs = tb.childNodes;
            for(var i =0; i<trs.length; i++){

                var current_tr = trs[i];
                if(current_tr.nodeType==1){
                    var inp = current_tr.firstElementChild.getElementsByTagName('input')[0];
                    inp.checked = true;//关键地方
                }
            }
        }

        function CancelAll(ths){
            var tb = document.getElementById('tb');
            var trs = tb.childNodes;
            for(var i =0; i<trs.length; i++){

                var current_tr = trs[i];
                if(current_tr.nodeType==1){
                    var inp = current_tr.firstElementChild.getElementsByTagName('input')[0];
                    inp.checked = false;//关键地方
                }
            }
        }

        function ReverseCheck(ths){
            var tb = document.getElementById('tb');
            var trs = tb.childNodes;
            for(var i =0; i<trs.length; i++){
                var current_tr = trs[i];
                if(current_tr.nodeType==1){
                    var inp = current_tr.firstElementChild.getElementsByTagName('input')[0];
                    if(inp.checked){
                        inp.checked = false;
                    }else{
                        inp.checked = true;//关键地方
                    }
                }
            }
        }

    </script>
</body>
</html>
View Code

 

posted @ 2017-03-07 17:07  Jhon23  阅读(130)  评论(0)    收藏  举报