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Ajax 傳遞JSON實(shí)例代碼

更新時(shí)間：2017年03月02日 09:14:40 作者：小火柴的藍(lán)色理想

雖然ajax全稱是asynchronous javascript and XML。但目前使用ajax技術(shù)時(shí)，傳遞JSON已經(jīng)成為事實(shí)上的標(biāo)準(zhǔn)。這篇文章主要介紹了Ajax 傳遞JSON實(shí)例代碼,需要的朋友可以參考下

前面的話

　　雖然ajax全稱是asynchronous javascript and XML。但目前使用ajax技術(shù)時(shí)，傳遞JSON已經(jīng)成為事實(shí)上的標(biāo)準(zhǔn)。因?yàn)橄噍^于XML而言，JSON簡單且方便。本文將上一篇中的實(shí)例進(jìn)行改寫，以JSON的方式來進(jìn)行數(shù)據(jù)傳遞

前端頁面

<!-- 前端頁面 -->
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
<style>
body{font-size: 20px;margin: 0;line-height: 1.5;}
select,button,input{font-size: 20px;line-height: 1.5;}
</style>
</head>
<body>
<h2>員工查詢</h2>  
<label>請輸入員工編號:</label>
<input type="text" id="keyword">
<button id="search">查詢</button>
<p id="searchResult"></p>
<h2>員工創(chuàng)建</h2>
<form id="postForm">
  <label>請輸入員工姓名：</label>
  <input type="text" name="name"><br>
  <label>請輸入員工編號：</label>
  <input type="text" name="number"><br>
  <label>請輸入員工性別：</label>
  <select name="sex">
  <option value="男">男</option>
  <option value="女">女</option>
  </select><br>
  <label>請輸入員工職位：</label>
  <input type="text" name="job"><br>
  <button id="save" type="button">保存</button>  
</form>
<p id="createResult"></p>
<script>
/*get*/
//查詢
var oSearch = document.getElementById('search');
//get方式添加數(shù)據(jù)
function addURLParam(url,name,value){
  url += (url.indexOf("?") == -1 ? "?" : "&");
  url +=encodeURIComponent(name) + "=" + encodeURIComponent(value);
  return url;
}
oSearch.onclick = function(){
  //創(chuàng)建xhr對象
  var xhr;
  if(window.XMLHttpRequest){
    xhr = new XMLHttpRequest();
  }else{
    xhr = new ActiveXObject('Microsoft.XMLHTTP');
  }
  //異步接受響應(yīng)
  xhr.onreadystatechange = function(){
    if(xhr.readyState == 4){
      if(xhr.status == 200){
        //實(shí)際操作
        var data = JSON.parse(xhr.responseText);
        if(data.success){
          document.getElementById('searchResult').innerHTML = data.msg;
        }else{
          document.getElementById('searchResult').innerHTML = '出現(xiàn)錯誤：' +data.msg;
        }
      }else{
        alert('發(fā)生錯誤：' + xhr.status);
      }
    }
  }
  //發(fā)送請求
  var url = 'service.php';
  url = addURLParam(url,'number',document.getElementById('keyword').value);
  xhr.open('get',url,true);
  xhr.send();
}
/*post*/
//創(chuàng)建
var oSave = document.getElementById('save');
//post方式添加數(shù)據(jù)
function serialize(form){    
  var parts = [],field = null,i,len,j,optLen,option,optValue;
  for (i=0, len=form.elements.length; i < len; i++){
    field = form.elements[i];
    switch(field.type){
      case "select-one":
      case "select-multiple":
        if (field.name.length){
          for (j=0, optLen = field.options.length; j < optLen; j++){
            option = field.options[j];
            if (option.selected){
              optValue = "";
              if (option.hasAttribute){
                optValue = (option.hasAttribute("value") ? option.value : option.text);
              } else {
                optValue = (option.attributes["value"].specified ? option.value : option.text);
              }
              parts.push(encodeURIComponent(field.name) + "=" + encodeURIComponent(optValue));
            }
          }
        }
        break;       
      case undefined:   //fieldset
      case "file":    //file input
      case "submit":   //submit button
      case "reset":    //reset button
      case "button":   //custom button
        break;        
      case "radio":    //radio button
      case "checkbox":  //checkbox
        if (!field.checked){
          break;
        }
        /* falls through */
      default:
        //don't include form fields without names
        if (field.name.length){
          parts.push(encodeURIComponent(field.name) + "=" + encodeURIComponent(field.value));
        }
    }
  }    
  return parts.join("&");
}
oSave.onclick = function(){
  //創(chuàng)建xhr對象
  var xhr;
  if(window.XMLHttpRequest){
    xhr = new XMLHttpRequest();
  }else{
    xhr = new ActiveXObject('Microsoft.XMLHTTP');
  }
  //異步接受響應(yīng)
  xhr.onreadystatechange = function(){
    if(xhr.readyState == 4){
      if(xhr.status == 200){
        //實(shí)際操作
        var data = JSON.parse(xhr.responseText);
        if(data.success){
         document.getElementById('createResult').innerHTML = data.msg; 
       }else{
         document.getElementById('createResult').innerHTML = '出現(xiàn)錯誤：'+data.msg;
       }
      }else{
        alert('發(fā)生錯誤：' + xhr.status);
      }
    }
  }
  //發(fā)送請求
  xhr.open('post','service.php',true);
  xhr.setRequestHeader("content-type","application/x-www-form-urlencoded");
  xhr.send(serialize(document.getElementById('postForm')));
}
</script>
</body>
</html>

后端頁面

<?php 
//用于過濾不安全的字符
function test_input($data) {
  $data = trim($data);
  $data = stripslashes($data);
  $data = htmlspecialchars($data);
  return $data;
}
//設(shè)置頁面內(nèi)容的html編碼格式是utf-8
header("Content-Type:application/json;charset=utf-8");
//定義一個多維數(shù)組，包含員工的信息，每條員工信息為一個數(shù)組
$staff = array(
  array("name"=>"洪七","number"=>"101","sex"=>"男","job"=>'總經(jīng)理'),
  array("name"=>"郭靖","number"=>"102","sex"=>"男","job"=>'開發(fā)工程師'),
  array("name"=>"黃蓉","number"=>"103","sex"=>"女","job"=>'產(chǎn)品經(jīng)理')
  );
//判斷如果是get請求，則進(jìn)行搜索；如果是POST請求，則進(jìn)行新建
//$_SERVER["REQUEST_METHOD"]返回訪問頁面使用的請求方法
if($_SERVER["REQUEST_METHOD"] == "GET"){
  search();
}else if($_SERVER["REQUEST_METHOD"] == "POST"){
  create();
}
//通過員工編號搜索員工
function search(){
  //檢查是否有員工編號的參數(shù)
  //isset檢測變量是否設(shè)置；empty判斷值是否為空
  if(!isset($_GET['number']) || empty($_GET['number'])){
    echo '{"success":false,"msg":"參數(shù)錯誤"}';
    return;
  }
  global $staff;
  $number = test_input($_GET['number']);
  $result = '{"success":false,"msg":"沒有找到員工"}';
  //遍歷$staff多維數(shù)組，查找key值為number的員工是否存在。如果存在，則修改返回結(jié)果
  foreach($staff as $value){
    if($value['number'] == $number){
      $result = '{"success":true,"msg":"找到員工：員工編號為' .$value["number"] .'，員工姓名為' .$value["name"] .'，員工性別為' .$value["sex"] .'，員工職位為' .$value["job"] .'"}';
      break;
    }
  }
  echo $result;
}
//創(chuàng)建員工
function create(){
  //判斷信息是否填寫完全
  if(!isset($_POST['name']) || empty($_POST['name']) || 
    !isset($_POST['number']) || empty($_POST['number']) ||
    !isset($_POST['sex']) || empty($_POST['sex']) ||
    !isset($_POST['job']) || empty($_POST['job']) 
    ){
    echo '{"success":false,"msg":"參數(shù)錯誤，員工信息填寫不全"}';
    return;
  }
  echo '{"success":true,"msg":"員工' .test_input($_POST['name']) .'信息保存成功!"}';
}
?>

實(shí)例演示