“未定义的索引:itemdetails”，当将JSON对象从JavaScript发送到PHP时 - “Undefined index: itemdetails” when sending JSON object from JavaScript to PHP

“Undefined index: itemdetails” when sending JSON object from JavaScript to PHP

输入商品数量并单击">添加到购物车"按钮后，将执行toShoppingCart()方法。此方法将获取标签和文本字段的值，并将它们插入到 JSON 对象中并将其传递给Order.php文件。

将 JSON 对象从 JavaScript 发送到 PHP 时，它会返回一个错误：

Undefined index: itemdetails

Onearlist.html ：

<html>
  <head>
    <title>TODO supply a title</title>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
  </head>
  <body>
    <form action="Order.php">
      <table border="2">
        <tr>
          <td>
            <div style="padding: 40px"><label id="id">001</label> <label id="name">SMS Audio street by 50 on-ear wired</label> &nbsp;<label id="price">179.00$</label>&nbsp;Qty <input type="text" id="qtytxt"><input type="button" value="Add to Cart" onclick="toShoppingCart()" /></div>
          </td>
        </tr>
        <tr>
          <td>
            <div style="padding: 40px"><label id="id">002</label><label id="name">Beats Solo2 on-ear wired</label> &nbsp;,<label id="price">199.00$</label> &nbsp; Qty<input type="text" id="qtytxt"><input type="button" value="Add to Cart" onclick="toShoppingCart()" /></div>
          </td>
        </tr>
        <tr>
          <td>
            <div style="padding: 60px"></div>
          </td>
        </tr>
      </table>
      <input type="submit" value="Check Out">
    </form>
    <script type="text/javascript">
      function toShoppingCart() {
        console.log("toShoppingCart");
        var id = document.getElementById("id").innerHTML;
        var name = document.getElementById("name").innerHTML;
        var qty = document.getElementById("qtytxt").value;
        var price = parseFloat(document.getElementById("price").innerHTML);
        console.log(id);
        console.log(name);
        console.log(qty);
        console.log(price);
        var request;
        var itemdata = {
          "id": id,
          "name": name,
          "qty": qty,
          "price": price
        };
        open("Order.php", "window1");
        send({
          itemdetails: JSON.stringify(itemdata)
        });
      }
    </script>
  </body>
</html>

Order.php ：

<?php
  $data = json_decode($_GET['itemdetails']);
  echo $data;
?>

要发送 ajax 请求，请执行以下操作：

var request = new XMLHttpRequest();
request.onreadystatechange = function () {
    var DONE = this.DONE || 4;
    if (this.readyState === DONE){
        alert(request.responseText); // get response form the server
    }
};
request.open('GET', 'Order.php?itemdetails='+JSON.stringify(itemdata), true);
request.setRequestHeader('X-Requested-With', 'XMLHttpRequest');
request.send(null);

或者如果你使用 jQuery，那么：

$.get('Order.php?itemdetails='+JSON.stringify(itemdata), function(response) {
});