ASP – AJAX 與 ASP
asp - ajax 與 asp
ajax 被用于創(chuàng)建交互性更強(qiáng)的應(yīng)用程序。
ajax asp 實(shí)例
下面的實(shí)例將演示當(dāng)用戶在輸入框中鍵入字符時(shí)，網(wǎng)頁如何與 web 服務(wù)器進(jìn)行通信：
實(shí)例
start typing a name in the input field below:
function showhint(str) { if (str.length==0) { document.getelementbyid("txthint").innerhtml=""; return; } if (window.xmlhttprequest) {// code for ie7+, firefox, chrome, opera, safari xmlhttp=new xmlhttprequest(); } else {// code for ie6, ie5 xmlhttp=new activexobject("microsoft.xmlhttp"); } xmlhttp.onreadystatechange=function() { if (xmlhttp.readystate==4 && xmlhttp.status==200) { document.getelementbyid("txthint").innerhtml=xmlhttp.responsetext; } } xmlhttp.open("get","gethint.asp?q="+str,true); xmlhttp.send(); } first name:suggestions:
實(shí)例解釋 - html 頁面
當(dāng)用戶在上面的輸入框中鍵入字符時(shí)，會(huì)執(zhí)行 "showhint()" 函數(shù)。該函數(shù)由 "onkeyup" 事件觸發(fā)：
function showhint(str)
{
if (str.length==0)
{
document.getelementbyid("txthint").innerhtml="";
return;
}
if (window.xmlhttprequest)
{// code for ie7+, firefox, chrome, opera, safari
xmlhttp=new xmlhttprequest();
}
else
{// code for ie6, ie5
xmlhttp=new activexobject("microsoft.xmlhttp");
}
xmlhttp.onreadystatechange=function()
{
if (xmlhttp.readystate==4 && xmlhttp.status==200)
{
document.getelementbyid("txthint").innerhtml=xmlhttp.responsetext;
}
}
xmlhttp.open("get","gethint.asp?q="+str,true);
xmlhttp.send();
}
start typing a name in the input field below:
first name:
suggestions:
源代碼解釋：
如果輸入框是空的（str.length==0），該函數(shù)會(huì)清空 txthint 占位符的內(nèi)容，并退出該函數(shù)。
如果輸入框不是空的，那么 showhint() 會(huì)執(zhí)行以下步驟：
- 創(chuàng)建 xmlhttprequest 對(duì)象
- 創(chuàng)建在服務(wù)器響應(yīng)就緒時(shí)執(zhí)行的函數(shù)
- 向服務(wù)器上的文件發(fā)送請(qǐng)求
- 請(qǐng)注意添加到 url 末端的參數(shù)（q）（包含輸入框的內(nèi)容）
asp 文件
上面這段通過 javascript 調(diào)用的服務(wù)器頁面是名為 "gethint.asp" 的 asp 文件。
"gethint.asp" 中的源代碼會(huì)檢查姓名數(shù)組，然后向?yàn)g覽器返回對(duì)應(yīng)的姓名：
<%
response.expires=-1
dim a(30)
'fill up array with names
a(1)="anna"
a(2)="brittany"
a(3)="cinderella"
a(4)="diana"
a(5)="eva"
a(6)="fiona"
a(7)="gunda"
a(8)="hege"
a(9)="inga"
a(10)="johanna"
a(11)="kitty"
a(12)="linda"
a(13)="nina"
a(14)="ophelia"
a(15)="petunia"
a(16)="amanda"
a(17)="raquel"
a(18)="cindy"
a(19)="doris"
a(20)="eve"
a(21)="evita"
a(22)="sunniva"
a(23)="tove"
a(24)="unni"
a(25)="violet"
a(26)="liza"
a(27)="elizabeth"
a(28)="ellen"
a(29)="wenche"
a(30)="vicky"
'get the q parameter from url
q=ucase(request.querystring("q"))
'lookup all hints from array if length of q>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
'output "no suggestion" if no hint were found
'or output the correct values
if hint="" then
response.write("no suggestion")
else
response.write(hint)
end if
%>
response.expires=-1
dim a(30)
'fill up array with names
a(1)="anna"
a(2)="brittany"
a(3)="cinderella"
a(4)="diana"
a(5)="eva"
a(6)="fiona"
a(7)="gunda"
a(8)="hege"
a(9)="inga"
a(10)="johanna"
a(11)="kitty"
a(12)="linda"
a(13)="nina"
a(14)="ophelia"
a(15)="petunia"
a(16)="amanda"
a(17)="raquel"
a(18)="cindy"
a(19)="doris"
a(20)="eve"
a(21)="evita"
a(22)="sunniva"
a(23)="tove"
a(24)="unni"
a(25)="violet"
a(26)="liza"
a(27)="elizabeth"
a(28)="ellen"
a(29)="wenche"
a(30)="vicky"
'get the q parameter from url
q=ucase(request.querystring("q"))
'lookup all hints from array if length of q>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
'output "no suggestion" if no hint were found
'or output the correct values
if hint="" then
response.write("no suggestion")
else
response.write(hint)
end if
%>
解釋：如果 javascript 發(fā)送了任何文本（即 strlen($q) > 0），則會(huì)發(fā)生：
ASP基礎(chǔ)