ajax 上传文件给webapi(带basic认证)

 
    $('#btnupload').on('click', function () {
        var fd = new FormData();
        var reportid = window.location.href.split('=')[1];
        fd.append("report_id", reportid);
        fd.append("txtfile", $("#txtfile").get(0).files[0]);
        $.ajax({
            url: "http://localhost:8081/api/file/PostFile",
            type: "POST",
            processData: false,
            contentType: false,
            headers: {
                "Authorization": "Basic " + btoa("admin" + ":" + "698d51a19d8a121ce581499d7b701668")
            },
            data: fd,
            success: function (d) {
                layer.msg('上传成功', { time: 1000 }, function () {
                    window.location.href = "@Url.Action("Index", "ReportList")";
                });
            }
        });
    });

   <input name="txtfile" id="txtfile" type="file" /><br />
                                        <input name="btnupload" class='btn btn-primary fa fa-save' id="btnupload" type="button" value="上传" />