This time I will show you how to achieve secondary linkage with Ajax combined with PHP. What are the precautions for achieving secondary linkage with Ajax combined with PHP? The following is a practical case, let’s take a look.
Use ajax to get data from php<!DOCTYPE html> <html> <head> <title>Ajax案例一</title> <meta charset="utf-8" /> </head> <body> <!-- 二级联动 --> <select id="province"> <option>请选择</option> <option>山东省</option> <option>辽宁省</option> <option>吉林省</option> </select> <select id="city"> <option>请选择</option> </select> <script> // 1. 为<select>元素绑定onchange事件 var provinceEle = document.getElementById("province"); provinceEle.onchange = function(){ // 将id为city的元素内容清空 var city = document.getElementById("city"); var opts = city.getElementsByTagName("option"); for(var z=opts.length-1;z>0;z--){ city.removeChild(opts[z]); } // 2. 获取用户当前选择的省份名称 var province = provinceEle.value; // 3. 创建对应的城市列表 - 数组 var cities = []; switch (province){ case "山东省": cities = ["青岛市","济南市","威海市","日照市","德州市"]; break; case "吉林省": cities = ["长春市","松原市","吉林市","通化市","四平市"]; break; case "辽宁省": cities = ["沈阳市","大连市","铁岭市","丹东市","锦州市"]; break; } // 遍历城市列表 for(var i=0;i<cities.length;i++){ // 4. 创建<option>元素 var option = document.createElement("option"); // 5. 将城市的信息添加到<option>元素上 var textNode = document.createTextNode(cities[i]); option.appendChild(textNode); // 6. 将创建的所有<option>元素添加到id为city元素上 city.appendChild(option); } } </script> </body> </html>
<?php // 用于处理客户端请求二级联动的数据 // 1. 接收客户端发送的省份信息 $province = $_POST['provcince']; // 2. 判断当前的省份信息,提供不同的城市信息 switch ($province){ case '山东省': echo '青岛市,济南市,威海市,日照市,德州市'; break; case '辽宁省': echo '沈阳市,大连市,铁岭市,丹东市,锦州市'; break; case '吉林省': echo '长春市,松原市,吉林市,通化市,四平市'; break; } // 服务器端响应的是字符串 ?>
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