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：
[url=]
[/url]
[/url]<!
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
>
[url=][/url]
[/url]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
PHP文件检查名称数组，并将相应的名称返回给浏览器：
[url=][/url]
[/url]<?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
;[url=][/url]
[/url]
