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  • javascript 处理表单元素

    一、通过表单name属性获取<form>表单的各元素 

     1 <form id="f1">
     2   <input type="text" tabindex="0" name="t1" value="输入内容" />
     3   <input type="radio" name="r1" value="1" />
     4   <input type="radio" name="r1" checked value="2" />
     5   <input type="radio" name="r1" value="3" />
     6 </form>
     7 
     8 <script>
     9   function getID(id){
    10     return document.getElementById(id);
    11   };
    12 
    13   var formID = getID("f1");
    14   console.log(formID.t1.value); // 获取name="t1"的值
    15 
    16   // 获取相同name值的一组元素
    17   console.log(formID.r1); // 返回的是一个数组节点
    18   for(var i=0; i<formID.r1.length; i++){
    19     if(formID.r1[i].checked){
    20     alert(formID.r1[i].value);
    21     }
    22   }
    23 </script>

     

    二、获取文本框的值

     1 <form id="f1">
     2   <input type="text" id="username" tabindex="0" name="t1" value="" />
     3   <input type="button" id="sendForm" value="提交" />
     4 </form>
     5 
     6 <script>
     7   function getID(id){
     8     return document.getElementById(id);
     9   };
    10 
    11   var text1 = getID("username");
    12   var sendBtn = getID("sendForm");
    13 
    14   sendBtn.onclick = function(){
    15     console.log(text1.value); // 获取文本元素的内容
    16   }
    17 </script>

    三、checkbox 多选元素的处理

     1 <form id="f1">
     2   <input type="checkbox" name="box1" value="1111" />1111
     3   <input type="checkbox" name="box1" value="2222" />2222
     4   <input type="checkbox" name="box1" value="3333" />3333
     5   <input type="checkbox" name="box1" value="4444" />4444
     6   <input type="button" id="sendForm" value="提交" />
     7   <input type="button" id="allBox" value="全选" />
     8   <input type="button" id="reverseBox" value="反选" />
     9 </form>
    10 
    11 <script>
    12   function getID(id){
    13     return document.getElementById(id);
    14   };
    15 
    16   var f1 = getID("f1").box1;
    17   var sendForm = getID("sendForm");
    18   var allBox = getID("allBox");
    19   var reverseBox = getID("reverseBox");
    20   var setVal = ""
    21 
    22   // 提取选中的元素
    23   sendForm.onclick = function(){
    24     for(var i=0; i<f1.length; i++){
    25       if(f1[i].checked){
    26         setVal += f1[i].value + ",";
    27       }
    28     }
    29     console.log(setVal)
    30   };
    31 
    32   // 全选
    33   allBox.onclick = function(){
    34     for(var i=0; i<f1.length; i++){
    35       f1[i].checked = true;
    36     }
    37   };
    38 
    39   // 反选
    40   reverseBox.onclick = function(){
    41     for(var i=0; i<f1.length; i++){
    42       if(f1[i].checked){
    43         f1[i].checked = false;
    44       }
    45       else{
    46         f1[i].checked = true;
    47       }
    48     }
    49   };
    50 </script>

    四、radio 单选框处理

     1 <form id="f1">
     2   <input type="radio" name="r1" value="" /> 3   <input type="radio" name="r1" value="" /> 4   <input type="radio" name="r2" value="城市" /> 城市
     5   <input type="radio" name="r2" value="乡村" /> 乡村
     6   <input type="button" id="sendForm" value="提交" />
     7 </form>
     8 
     9 <script>
    10 function getID(id){
    11   return document.getElementById(id);
    12 };
    13 
    14 var sex = getID("f1").r1;
    15 var city = getID("f1").r2;
    16 var sendForm = getID("sendForm");
    17 var setR1 = "", setR2 = "";
    18 
    19 for(var i=0; i<sex.length; i++){  // 侦听选择项并存储
    20   sex[i].onclick = function(){
    21     setR1 = this.value;
    22   };
    23 
    24   city[i].onclick = function(){
    25     setR2 = this.value;
    26   }
    27 }
    28 
    29 sendForm.onclick = function(){
    30   if(setR1 === ""){
    31     alert("请选择您的性别");
    32     return false;
    33   }
    34   if(setR2 === ""){
    35     alert("请选择所在的城市类型");
    36     return false;
    37   }
    38   alert(setR1 + "," + setR2);
    39 }
    40 </script>

    五、<select> 菜单

     1 <form id="f1">
     2   <select id="sel"></select>
     3   <input type="button" id="sendForm" value="提交" />
     4 </form>
     5 
     6 <script>
     7   var banks = [{"bankCode":"ICBC","bankName":"中国工商银行","imgURL":"images/bankimg/gs.jpg"},{"bankCode":"CCB","bankName":"中国建设银行","imgURL":"images/bankimg/js.jpg"},{"bankCode":"ABC","bankName":"中国农业银行","imgURL":"images/bankimg/ny.jpg"},{"bankCode":"BOCO-NET-B2C","bankName":"交通银行","imgURL":"images/bankimg/jt.jpg"},{"bankCode":"CMBCHINA","bankName":"招商银行","imgURL":"images/bankimg/zs.jpg"},{"bankCode":"BOC","bankName":"中国银行","imgURL":"images/bankimg/zg.jpg"},{"bankCode":"CEB","bankName":"中国光大银行","imgURL":"images/bankimg/gd.jpg"},{"bankCode":"ECITIC-NET-B2C","bankName":"中信银行","imgURL":"images/bankimg/zx.jpg"},{"bankCode":"SPDB","bankName":"浦发银行","imgURL":"images/bankimg/pf.jpg"},{"bankCode":"CMBC","bankName":"中国民生银行","imgURL":"images/bankimg/ms.jpg"},{"bankCode":"CIB","bankName":"兴业银行","imgURL":"images/bankimg/xy.jpg"},{"bankCode":"GDB","bankName":"广发银行","imgURL":"images/bankimg/gf.jpg"}];
     8 
     9 function getID(id){
    10   return document.getElementById(id);
    11 };
    12 
    13 var sel = getID("sel");
    14 var sendBtn = getID("sendForm");
    15 
    16 // 填加option元素
    17 function addOption(){
    18   var addOption = "";
    19   for(var i=0; i<banks.length; i++){
    20     addOption += "<option value='" + banks[i].bankCode + "'>" + banks[i].bankName + "</option>";
    21   }
    22   sel.innerHTML = addOption;
    23 };
    24 addOption();
    25 
    26 // 获取当前的焦点下标和选中的值
    27 sel.onchange = function(){
    28   var _index = sel.selectedIndex;
    29   console.log("下标:" +_index);
    30   var _val = sel.options[_index].value;
    31   console.log("选中的值:" + _val);
    32 }
    33 </script>

    1、select默认是inline元素,你可以
       select
       {
          display:block;
       }


    2、默认select会选择第一项option,如果初始状态不选可以:
       jq写法: $("select").each(function(){this.selectedIndex=-1});
     
       或者干脆加个冗余option: 
       <select>
        <option>请选择网站...</option>
        <option value="http://www.qq.com">腾讯网</option>
        <option value="http://www.163.com">网易</option>
        <option value="http://www.google.com">谷歌</option>
       </select>


    3、获取选择项的值:
       <select id="ddlCities" onchange="alert(this.options[this.selectedIndex].value);">
        <option value="0">北京</option>
        <option value="1">济南</option>
        <option value="2">威海</option>
       </select>
     
       获取文本:  
       this.options[this.selectedIndex].text
     
       更简洁的直接selectObj.value
     


    4、多选: 

     1 <select id="ddlCities" multiple="multiple" size="2">
    2 <option value="0">北京</option>
    3 <option value="1">济南</option>
    4 <option value="2">威海</option>
    5 </select>
    6

    7 使用jq获取选择,仅测试所以写在标签上:
      <select id="ddlCities" multiple="multiple" size="2" onchange="alert($(this).find('option:selected').text());">
    8 <option value="0">北京</option>
    9 <option value="1">济南</option>
    10 <option value="2">威海</option>
    11 </select>
    12

    13 如果纯js写,需要循环了:
      <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
    14 <html xmlns="http://www.w3.org/1999/xhtml">
    15 <head>
    16 <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
    17 <title>无标题文档</title>
    18 <style type="text/css">
    19 select
    20 {
    21 display:block;
    22 }
    23 </style><script type="text/javascript">
    24 function ddlCities_onchange(theSel){
    25 var arr=[];
    26 for(var i=0;i<theSel.options.length;i++){
    27 if(theSel.options[i].selected)
    28 arr.push(theSel.options[i].innerText);
    29 }
    30 alert(arr.join());
    31 }
    32 </script>
    33 </head>
    34
    35 <body>
    36 <select>
    37 <option>请选择网站...</option>
    38 <option value="http://www.qq.com">腾讯网</option>
    39 <option value="http://www.163.com">网易</option>
    40 <option value="http://www.google.com">谷歌</option>
    41 </select>
    42
    43 <select id="ddlCities" multiple="multiple" size="2" onchange="ddlCities_onchange(this);">
    44 <option value="0">北京</option>
    45 <option value="1">济南</option>
    46 <option value="2">威海</option>
    47 </select>
    48 </body>
    49 </html>

     

    5、添加移除option:
       jq添加: $("<option value='3'>南京</option>").appendTo($("#ddlCities"));
     
       js写法:  
       var anOption = document.createElement_x("option");
       anOption.text="南京";
       anOption.value="4";
       document.getElementByIdx_x("ddlCities").options.add(anOption);
       或者

       document.getElementByIdx_x("ddlCities").add(anOption);

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  • 原文地址:https://www.cnblogs.com/couxiaozi1983/p/3140224.html
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