// ajax 请求封装
function ajaxRequest(url, type, data, async, beforeFn, successFn, errorFn, contentType) {
    $.ajax({
        url: url,
        type: type,
        headers: {
            "authorization": localStorage.getItem("zhgd_token")
        },
        data: data,
        async: async,
        beforeSend: beforeFn,
        contentType: contentType || "application/x-www-form-urlencoded; charset=utf-8",
        success: successFn,
        error: errorFn
    });
}