Javascript實現動態菜單添加的實例代碼

2024-05-06 15:48:38

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在注冊信息的時候，常常需要通過下拉菜單讓用戶選擇，而且希望用戶在第一個下拉框做的選擇，影響第二個下拉框的內容。有時候，如果第一個下拉框不作出選擇，第二個下拉框根本不會頁面上顯示，為了給用戶呈現一個更清晰的頁面。

先來看看效果：

Html源碼：

復制代碼代碼如下:

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>動態改變菜單</title>
<script type="text/javascript" src="jquery.js"></script>
<script type="text/javascript" src="SelectMenu.js"></script>
</head>
<body>
<form action="#">
<br/>
<br/>
<br/>
    <div>
        <span>Province：
            <select>
                <option value="" selected="selected">Please Choose Province</option>
                <option value="HeBei">HeBei</option>
                <option value="ShanDong">ShanDong</option>
            </select>
        </span>
        <span>City：
            <select>
            </select>
        </span>
        <span>Area：
            <select>
            </select>
        </span>
        <br/>
         <br/>
        <span>
        </span>
    </div>
</form>
</body>
</html>

Javascript源碼

復制代碼代碼如下:

$(document).ready(function () {
    //找到三個下拉框
    var ProvinceSelect = $(".Province").children("select");
    var CitySelect = $(".City").children("select");
    var AreaSelect = $(".Area").children("select");
    var AddressSelect=$(".AddressSelect");
    //給第二個下拉框注冊事件
    ProvinceSelect.change(function () {
        //1、獲取當前下拉框的值
         var ProvinceValue = $(this).val();
        //1.1只要第一個下拉框內容有變化，第三個下拉框就要隱藏起來
        AreaSelect.parent().hide();
        AddressSelect.hide();
        AddressSelect.html("");
        //2、如果值不為空，則顯示城市下拉框
         if (ProvinceValue != "") {
                   CitySelect.html("");
                   $("<option value=''>Please Choose City</option>").appendTo(CitySelect);
                    switch(ProvinceValue)
                       {
                        //實際項目中，這個城市數組肯定是在服務器獲取的，這里為了簡便，我就直接自定義了一個數組
                        //如果追求完美，這里還可以加一道緩存，防止重復獲取
                       case "HeBei":
                            var CityOfHeBei=["ShiJiaZhuang","CangZhou","LangFang"];
                            for(var i=0;i<CityOfHeBei.length;i++){
                                $("<option value='"+CityOfHeBei[i]+"'>"+CityOfHeBei[i]+"</option>").appendTo(CitySelect);
                            }
                             break;
                       case "ShanDong":
                            var CityOfShanDon=["JiNan","DeZhou","QingDao"];
                            for(var i=0;i<CityOfShanDon.length;i++){
                                $("<option value='"+CityOfShanDon[i]+"'>"+CityOfShanDon[i]+"</option>").appendTo(CitySelect);
                            }
                            break;
                       }
                 CitySelect.parent().show();
        } else {
            CitySelect.parent().hide();
        }
    });
    //給第二個下拉框注冊事件
     CitySelect.change(function () {
            var CityValue = $(this).val();
            AddressSelect.hide();
            AreaSelect.parent().hide();
            AddressSelect.html("");
             if (CityValue != "") {
                   AreaSelect.html("");
                   $("<option value=''>Please Choose Area</option>").appendTo(AreaSelect);
                    switch(CityValue)
                       {
                       //實際項目中，這個區數組肯定是在服務器獲取的，這里為了簡便，我就直接自定義了一個數組
                       //如果追求完美，這里還可以加一道緩存，防止重復獲取
                       case "ShiJiaZhuang":
                            var AreaOfCity=["GaoXinQu","KaiFaQu","XinHuaQu"];
                            for(var i=0;i<AreaOfCity.length;i++){
                                $("<option value='"+AreaOfCity[i]+"'>"+AreaOfCity[i]+"</option>").appendTo(AreaSelect);
                            }
                             break;
                       case "CangZhou":
                            var AreaOfCity=["XinHuaQu","YunHeQu"];
                            for(var i=0;i<AreaOfCity.length;i++){
                                $("<option value='"+AreaOfCity[i]+"'>"+AreaOfCity[i]+"</option>").appendTo(AreaSelect);
                            }
                            break;
                       case "LangFang":
                            var AreaOfCity=["AnCiQu","GuangYangQu"];
                            for(var i=0;i<AreaOfCity.length;i++){
                                $("<option value='"+AreaOfCity[i]+"'>"+AreaOfCity[i]+"</option>").appendTo(AreaSelect);
                            }
                            break;
                       case "QingDao":
                            var AreaOfCity=["GaoXinQu","KaiFaQu","XinHuaQu"];
                            for(var i=0;i<AreaOfCity.length;i++){
                                $("<option value='"+AreaOfCity[i]+"'>"+AreaOfCity[i]+"</option>").appendTo(AreaSelect);
                            }
                             break;
                       case "DeZhou":
                            var AreaOfCity=["XinHuaQu","YunHeQu"];
                            for(var i=0;i<AreaOfCity.length;i++){
                                $("<option value='"+AreaOfCity[i]+"'>"+AreaOfCity[i]+"</option>").appendTo(AreaSelect);
                            }
                            break;
                       case "JiNan":
                            var AreaOfCity=["AnCiQu","GuangYangQu"];
                            for(var i=0;i<AreaOfCity.length;i++){
                                $("<option value='"+AreaOfCity[i]+"'>"+AreaOfCity[i]+"</option>").appendTo(AreaSelect);
                            }
                            break;
                       }
                     AreaSelect.parent().show();
             } else {
                     AreaSelect.parent().hide();
            }
    });
    AreaSelect.change(function(){
            var AreaValue=$(this).val();
            AddressSelect.html("");
            if (AreaValue!=""){
                $("<span>The Address Is --Province: "+ProvinceSelect.val()+" City: "+CitySelect.val()+" Area: "+AreaSelect.val()+"</span>").appendTo(AddressSelect);
            AddressSelect.show();
            //alert("The Address Is Province: "+ProvinceSelect.val()+" City: "+CitySelect.val()+" Area: "+AreaSelect.val());
                }
     })
});