阮一峰的IT笔记

var bXmlHttpSupport = (typeof XMLHttpRequest == “object” || window.ActiveXObject);

var Http = new Object;

定义回调函数：

function callback_function(sData) {
//interpret data here
}

定义GET方法：

Http.get = function (sURL, fnCallback) {
if (bXmlHttpSupport) {
var oRequest = new XMLHttpRequest();
oRequest.open(“get”, sURL, true);
oRequest.onreadystatechange = function () {
if (oRequest.readyState == 4) {
fnCallback(oRequest.responseText);
}
}
oRequest.send(null);
} else {
alert(“Your browser doesn’t support HTTP requests.”);
}
};

GET方法使用示例：

var sURL = “http://www.somewhere.com/page.php”;
sURL = addURLParam(sURL, “name”, “Nicholas”);
sURL = addURLParam(sURL, “book”, “Professional JavaScript”);
Http.get(sURL, function(sData) {
alert(“Server sent back: “ + sData);
});

定义POST方法：

Http.post = function (sURL, sParams, fnCallback) {
if (bXmlHttpSupport) {
var oRequest = new XMLHttpRequest();
oRequest.open(“post”, sURL, true);
oRequest.setRequestHeader(“Content-Type”,
“application/x-www-form-urlencoded”);
oRequest.onreadystatechange = function () {
if (oRequest.readyState == 4) {
fnCallback(oRequest.responseText);
}
}
oRequest.send(sParams);
} else {
alert(“Your browser doesn’t support HTTP requests.”);
}
};

使用POST方法示例：

var sURL = “http://www.somewhere.com/page.php”;
var sParams = “”;
sParams = addPostParam(sParams, “name”, “Nicholas”);
sParams = addPostParam(sParams, “book”, “Professional JavaScript”);
oHttp.post(sURL, function(sData) {
alert(“Server sent back: “ + sData);
});