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

// 文件上传
function ajaxRequest2(url, type, data, beforeFn, successFn, errorFn) {
    $.ajax({
        url: url,
        type: type,
        data: data,
        headers: {
            "token": tokens
        },
        async:true,
        dataType: 'json',
        processData: false,
        contentType: false,
        beforeSend: beforeFn,
        success: successFn,
        error: errorFn
    });
}