How to use ajax function
This article mainly introduces how to use the ajax function, has a certain reference value, interested friends can refer to, I hope you can learn a lot after reading this article, the following let the editor take you to understand it.
The code is as follows:
/ *
Call method:
1.POST mode
Var txt = escape (sender.value); / / document.getElementById (") .value)
Var data = "name=" + txt + "& pwd=" + txt
Var option = {"url": "handler/Handler.ashx"
, "action": "POST"
, "callback": function () {
If (xmlHttp.readyState = = 4) {/ / the server responded
If (xmlHttp.status = = 200) {/ / Service responds correctly
Alert (xmlHttp.responseText)
}
XmlHttp = null; / / Recycling Resources
}
}
, "data": data
}
Ajax (option)
2.GET mode
Var txt = escape (sender.value); / / document.getElementById (") .value)
Var option = {"url": "handler/Handler.ashx&name=" + txt + "& pwd=" + txt
, "action": "POST"
, "callback": function () {
If (xmlHttp.readyState = = 4) {/ / the server responded
If (xmlHttp.status = = 200) {/ / Service responds correctly
Alert (xmlHttp.responseText)
}
XmlHttp = null; / / Recycling Resources
}
}
}
Ajax (option)
, /
Function ajax (option) {
CreateXMlHttpRequest (); / / create a xmlHttpRequest object
If (option! = null & & option! = undefined) {
If (option.url = = null & & option.url = = undefined) {
XmlHttp = null
Alert ("missing necessary parameter option.url")
Return
}
If (option.action = = null & & option.action = = undefined) {
XmlHttp = null
Alert ("missing necessary parameter option.action")
Return
}
XmlHttp.open (option.action, option.url, true)
If (option.contentType! = null & & option.contentType! = undefined) {
XmlHttp.setRequestHeader ("Content-Type", option.contentType)
} else {
XmlHttp.setRequestHeader ("Content-Type", "application/x-www-form-urlencoded")
}
If (option.callback! = null & & option.callback! = undefined) {
XmlHttp.onreadystatechange = option.callback
}
If (option.action.toUpperCase ()) = = "POST") {
XmlHttp.send (option.data)
} else {
XmlHttp.send (null)
}
}
}
It is best to recycle xmlHttp = null after the var xmlHttp; / / call is completed.
/ * get the element * /
Function g (arg) {
Var t = document.getElementById (arg)
If (null! = t & & t! = undefined) {
Return t
}
T = document.getElementsByName (arg)
If (null! = t & & t! = undefined) {
Return t
}
T = document.getElementsByTagName (arg)
If (null! = t & & t! = undefined) {
Return t
}
}
/ * create an ajax request object * /
Function createXMlHttpRequest () {
Try {/ / Firefox, Chrome, Surfri, Opera+8
XmlHttp = new XMLHttpRequest ()
}
Catch (ie) {
Try {/ / IE6+
XmlHttp = new ActiveXObject ("Msxml2.XMLHTTP")
} catch (ie) {
XmlHttp = new ActiveXObject ("Microsoft.XMLHTTP")
}
}
Return xmlHttp
}
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