JavaScript AJAX PHP
作者:互联网
AJAX PHP示例
AJAX用于创建更多交互式应用程序。 以下示例演示了当用户在输入字段中键入字符时,网页如何与Web服务器通信:<!DOCTYPE html> <html> <meta charset="utf-8"> <title>ajax</title> <body> <h2> XMLHttpRequest 对象 </h2> <h3>开始在下面的input字段中键入名称:</h3> <p>建议: <span id="txtHint"></span></p> <p>First name: <input type="text" id="txt1" onkeyup="showHint(this.value)"></p> <script> function showHint(str) { var xhttp; if (str.length == 0) { document.getElementById("txtHint").innerHTML = ""; return; } xhttp = new XMLHttpRequest(); xhttp.onreadystatechange = function() { if (this.readyState == 4 && this.status == 200) { document.getElementById("txtHint").innerHTML = this.responseText; } }; xhttp.open("GET", "/jc_script/gethint.php?q="+str, true); xhttp.send(); } </script> </body> </html>
在上面的示例中,当用户在输入字段中键入字符时,showHint()执行被调用的函数。该函数由onkeyup事件触发。
代码说明:首先,检查input字段是否为空(str.length == 0)。如果是,请清除txtHint占位符的内容并退出该函数。但是,如果输入字段不为空,请执行以下操作:- 创建XMLHttpRequest对象
- 创建服务器响应准备好时要执行的函数
- 将请求发送到服务器上的PHP文件(gethint.php)
- 请注意,“gethint.php?q=“+ str添加了q参数
-
str变量保存input字段的内容
PHP文件 - “gethint.php”
PHP文件检查名称数组,并将相应的名称返回给浏览器:<?php// 带名字的数组 $a[] = "Anna";$a[] = "Brittany"; $a[] = "Cinderella"; $a[] = "Diana"; $a[] = "Eva"; $a[] = "Fiona"; $a[] = "Gunda"; $a[] = "Hege"; $a[] = "Inga"; $a[] = "Johanna"; $a[] = "Kitty"; $a[] = "Linda"; $a[] = "Nina"; $a[] = "Ophelia"; $a[] = "Petunia"; $a[] = "Amanda"; $a[] = "Raquel"; $a[] = "Cindy"; $a[] = "Doris"; $a[] = "Eve"; $a[] = "Evita"; $a[] = "Sunniva"; $a[] = "Tove"; $a[] = "Unni"; $a[] = "Violet"; $a[] = "Liza"; $a[] = "Elizabeth"; $a[] = "Ellen"; $a[] = "Wenche"; $a[] = "Vicky"; // 从URL获取q参数 $q = $_REQUEST["q"]; $hint = ""; // 如果$q不等于"",则从数组中查找所有提示 if ($q !== "") { $q = strtolower($q); $len=strlen($q); foreach($a as $name) { if (stristr($q, substr($name, 0, $len))) { if ($hint === "") { $hint = $name; } else { $hint .= ", $name"; } } } } // 如果未找到提示或输出正确值,则输出“无建议” echo $hint === "" ? "无建议" : $hint;
更详细的AJAX文章教程
标签:php,JavaScript,AJAX,xhttp,gethint,字段,str,PHP 来源: https://www.cnblogs.com/jc2182/p/11298471.html