原生javascript实现AJAX的代码示例

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原生JS使用AJAX使用代码，代码如下

var xhr1 = new XMLHttpRequest;
 xhr1.open("POST", 'http://47.92.121.171:17788', true);
 xhr1.setRequestHeader('Content-type', 'application/x-www-form-urlencoded');
 xhr1.onreadystatechange = function () {
 if (xhr1.readyState == 4 && xhr1.status == 200) {
 console.log("打印用户信息1" + xhr1.responseText);
 }
 }

 xhr1.send("code=p_001&name=aaaaaa&pas=123456&belong=aabbccdd");

如果需要ajax运行方法完成后调用结果的话 需要使用回调函数 或者 promise

回调函数

 private loadXMLDoc(url, sendcode, cfunc) {
 this.xmlhttp = new XMLHttpRequest;
 this.xmlhttp.open("POST", url, true);
 this.xmlhttp.setRequestHeader('Content-type', 'application/x-www-form-urlencoded');
 this.xmlhttp.onreadystatechange = cfunc;
 this.xmlhttp.send(sendcode);
 }
 private myFunction() {
 this.loadXMLDoc("http://47.92.121.171:17788", "code=p_001&name=aaaaaa&pas=123456&belong=aabbccdd",()=>{
 if (this.xmlhttp.readyState == 4 && this.xmlhttp.status == 200) {
 console.log("3")
 console.log("打印用户信息1" + this.xmlhttp.responseText) 
 }
 });
 }

使用promise

this.getGameServer().then(function (res) {
 console.log("res" + res);
 }).catch(function (rej) {
 console.log("rej" + rej);
 });private getGameServer() {
 return new Promise(function (resolve, reject) {
 var xhr = new XMLHttpRequest;
 xhr.open("POST", 'http://47.92.121.171:9002/rout/get_game_servers', true);
 xhr.setRequestHeader('Content-type', 'application/x-www-form-urlencoded');
 xhr.onreadystatechange = function () { 
 if (xhr.readyState == 4 && xhr.status == 200) {
 resolve(xhr.responseText);
 }
 }
 xhr.send("game=1&shang=common");
 });
 }