问使用ajax和c# web方法代码调用上载文件控件

EN

$scope.myData.updateimage = function(item, event) {

    var data = new FormData();

    var files = $("#FileUpload1").get(0).files;

    // Add the uploaded image content to the form data collection
    if (files.length > 0) {
        data.append("UploadedImage", files[0]);
    }

    $.ajax({
        type: "POST",
        url: "contentlist.aspx/updateid",
        data: JSON.stringify({
            FileUpload: data,
            currentid: $scope.currentid
        }),
        contentType: "application/json; charset=utf-8",
        dataType: "json",
        success: function(msg) {

        }
    });
}

[WebMethod]
public static string updateid(FileUpload FileUpload1, string currentid)
{

    HttpContext context = HttpContext.Current;
    string baseUrl = context.Request.Url.Authority + context.Request.ApplicationPath.TrimEnd('/');

    if (FileUpload1.HasFile)
    {
        try
        {
            if (FileUpload1.PostedFile.ContentLength < 3267633)
            {
                string strname = FileUpload1.FileName.ToString();
                string url = "http://" + baseUrl + "/Images/" + strname;
                FileUpload1.PostedFile.SaveAs(url);
                int id = Convert.ToInt16(appVars.updatedid);
                string Query = "UPDATE SubCategories SET imageurl = WHERE id = " + id;
                string result = dbAccess.ExecuteOnlyQuery(Query);
            }
            else
            {


            }
        }
        catch (Exception ex)
        {

        }
    }

    return "";
}