Eine kurze Diskussion über asynchrone jQuery-Objekte (XMLHttpRequest)_Javascript-Kenntnisse

//1.00Asynchrones Objekt erstellen
          var xhr = new XMLHttpRequest();
                    //2.0
                xhr.open("post", url,params, true);
//3.0 verwendet das Formdata-Attribut, um Parameter
zu übergeben                 xhr.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
//4.0 Rückruffunktion festlegen
                 xhr.onreadystatechange = function () {
If (xhr.readyState == 4 && xhr.status == 200) {
alarm(xhr.responseText);
                }
            }
//5.0 Übergabeparameter
                xhr.send(params);

xhr.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");

var ajaxHelp = {
    CreatXHR: Funktion () {
        //创建异步对象
        var xhr = new XMLHttpRequest();
        return xhr;
    },
    //ajax的get请求
    AjaxGet: Funktion (URL, CallBack) {
        this.AJaxCommon("get", url, null, callBack);
    },
    //ajax的post请求
    AjaxPost: Funktion (URL, Parameter, CallBack) {
        this.AJaxCommon("post", url, params, callBack);
    },
    AJaxCommon: Funktion (Methode, URL, Parameter, CallBack) {
        //1.0
        var xhr = this.CreatXHR();
        //2.0
        xhr.open(method, url, true);
        //3.0
        if (method == "get") {
            xhr.setRequestHeader("If-Modified-Since", "0");
        } sonst {
            xhr.setRequestHeader("Content-Type", "application/x-www-form-urlencoded");
        }
        //4.0
        xhr.onreadystatechange = function () {
            if (xhr.readyState == 4 && xhr.status == 200) {
                var datas = JSON.parse(xhr.responseText);
                //执行回调函数
                callBack(datas);
            }
        }
        //5.0
        xhr.send(params);
    }
};