AJAX 用于创建更具交互性的应用程序
首先,检查输入字段是否为空(str.length == 0),如果是,清空 txtHint 占位符的内容并退出函数。
不过,如果输入字段不为空,则进行如下:
<!DOCTYPE html> <html> <body> <h1>XMLHttpRequest 对象</h1> <h2>请在下面的输入字段中键入字母 A-Z:</h2> <form>姓名:<input type="text" id="txt1" onkeyup="showHint(this.value)"></form> <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", "/demo/gethint.php?q="+str, true); xhttp.send(); } } </script> </body> </html>
这个 PHP 文件检查姓名数组,然后向浏览器返回对应的姓名:
<?php // 姓名数组 $a[] = "Ava"; $a[] = "Brielle"; $a[] = "Caroline"; $a[] = "Diana"; $a[] = "Elise"; $a[] = "Fiona"; $a[] = "Grace"; $a[] = "Hannah"; $a[] = "Ileana"; $a[] = "Jane"; $a[] = "Kathryn"; $a[] = "Laura"; $a[] = "Millie"; $a[] = "Nancy"; $a[] = "Opal"; $a[] = "Petty"; $a[] = "Queenie"; $a[] = "Rose"; $a[] = "Shirley"; $a[] = "Tiffany"; $a[] = "Ursula"; $a[] = "Victoria"; $a[] = "Wendy"; $a[] = "Xenia"; $a[] = "Yvette"; $a[] = "Zoe"; $a[] = "Angell"; $a[] = "Adele"; $a[] = "Beatty"; $a[] = "Carlton"; $a[] = "Elisabeth"; $a[] = "Violet"; // 从 URL 获取 q 参数 $q = $_REQUEST["q"]; $hint = ""; // 查看数组中所有 hint,$q 是否与 "" 相同 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"; } } } } // 输出 "no suggestion",如果未找到 hint 或输出正确的值 echo $hint === "" ? "no suggestion" : $hint; ?>
这个 ASP 文件检查姓名数组,然后向浏览器返回对应的姓名:
<% response.expires=-1 dim a(32) '用姓名填充数组 a(1)="Ava" a(2)="Brielle" a(3)="Caroline" a(4)="Diana" a(5)="Elise" a(6)="Fiona" a(7)="Grace" a(8)="Hannah" a(9)="Ileana" a(10)="Jane" a(11)="Kathryn" a(12)="Laura" a(13)="Millie" a(14)="Nancy" a(15)="Opal" a(16)="Petty" a(17)="Queenie" a(18)="Rose" a(19)="Shirley" a(20)="Tiffany" a(21)="Ursula" a(22)="Victoria" a(23)="Wendy" a(24)="Xenia" a(25)="Yvette" a(26)="Zoe" a(27)="Angell" a(28)="Adele" a(29)="Beatty" a(30)="Carlton" a(31)="Elisabeth" a(32)="Violet" '从 URL 获取 q 参数 q=ucase(request.querystring("q")) '查看数组中所有 hint,q 的长度是否大于 0 if len(q)>0 then hint="" for i=1 to 30 if q=ucase(mid(a(i),1,len(q))) then if hint="" then hint=a(i) else hint=hint & " , " & a(i) end if end if next end if '如果未找到 hint,输出 "no suggestion",或输出正确的值 if hint="" then response.write("no suggestion") else response.write(hint) end if %>