JSLint 对象到第 22 行：
function() { return new ActiveXObject('Msxml2.XMLHTTP'); },
在 reqTry 数组中。有什么办法可以更改代码以防止 JSLint 出现此错误？
它还反对下一行。
function Ajax() {
this.req = null;
this.url = null;
this.status = null;
this.statusText = '';
this.method = 'GET';
this.async = true;
this.dataPayload = null;
this.readyState = null;
this.responseText = null;
this.responseXML = null;
this.handleResp = null;
this.responseFormat = 'text'; // 'text', 'xml', 'object'
this.mimeType = null;
this.headers = [];
this.init = function() {
var i = 0;
var reqTry = [
function() { return new XMLHttpRequest(); },
function() { return new ActiveXObject('Msxml2.XMLHTTP'); },
function() { return new ActiveXObject('Microsoft.XMLHTTP' ); } ];
while (!this.req && (i < reqTry.length)) {
try {
this.req = reqTry[i++]();
}
catch(e) {}
}
return true;
};
this.doGet = function(url, hand, format) {
this.url = url;
this.handleResp = hand;
this.responseFormat = format || 'text';
this.doReq();
};
this.doPost = function(url, dataPayload, hand, format) {
this.url = url;
this.dataPayload = dataPayload;
this.handleResp = hand;
this.responseFormat = format || 'text';
this.method = 'POST';
this.doReq();
};
this.doReq = function() {
var self = null;
var req = null;
if (!this.init()) {
alert('Could not create XMLHttpRequest object.');
return;
}
req = this.req;
req.open(this.method, this.url, this.async);
if (this.method == "POST") {
this.req.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
}
if (this.method == 'POST') {
req.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
}
self = this;
req.onreadystatechange = function() {
var resp = null;
self.readyState = req.readyState;
if (req.readyState == 4) {
self.status = req.status;
self.statusText = req.statusText;
self.responseText = req.responseText;
self.responseXML = req.responseXML;
switch(self.responseFormat) {
case 'text':
resp = self.responseText;
break;
case 'xml':
resp = self.responseXML;
break;
case 'object':
resp = req;
break;
}
if (self.status > 199 && self.status < 300) {
if (!self.handleResp) {
alert('No response handler defined ' +
'for this XMLHttpRequest object.');
return;
}
else {
self.handleResp(resp);
}
}
else {
self.handleErr(resp);
}
}
};
req.send(this.dataPayload);
};
this.abort = function() {
if (this.req) {
this.req.onreadystatechange = function() { };
this.req.abort();
this.req = null;
}
};
this.handleErr = function() {
var errorWin;
// Create new window and display error
try {
errorWin = window.open('', 'errorWin');
errorWin.document.body.innerHTML = this.responseText;
}
// If pop-up gets blocked, inform user
catch(e) {
alert('An error occurred, but the error message cannot be' +
' displayed because of your browser\'s pop-up blocker.\n' +
'Please allow pop-ups from this Web site.');
}
};
this.setMimeType = function(mimeType) {
this.mimeType = mimeType;
};
this.setHandlerResp = function(funcRef) {
this.handleResp = funcRef;
};
this.setHandlerErr = function(funcRef) {
this.handleErr = funcRef;
};
this.setHandlerBoth = function(funcRef) {
this.handleResp = funcRef;
this.handleErr = funcRef;
};
this.setRequestHeader = function(headerName, headerValue) {
this.headers.push(headerName + ': ' + headerValue);
};
}