如何将文件附件作为参数从Ajax传递到Web服务调用

Question

我试图通过传递一些参数从ajax调用Web服务。我的问题是我必须将附件和这些参数一起发送，并且必须通过Web服务方法将附件上传到特定位置。

$.ajax({
  type: "POST",
  url: 'API/WebService1.asmx/savePerformanceActivity',
  data: {
    prodCode: $("#<%=productCode.ClientID%>").val(),
    comm: $("#<%=CommentsActivity.ClientID%>").val(),
    uid: user,
    cat: $("#<%=Category.ClientID%>").val(),
    CpdActId: $("#<%=CPDActivityID.ClientID%>").val(),
    act: $("#<%=Activity.ClientID%>").val(),
    point: $("#<%=pointsActivity.ClientID%>").val(),
    date: $("#<%=activityDate.ClientID%>").val(),
    dec: $("#<%=CheckBox1.ClientID%>").val(),
    usersName: '<%=Session["IIT_UfName"].ToString()%>',
    cpdstream: $("#<%=cpdstream.ClientID%>").val(),
    filename: $("#<%=img.ClientID%>").val()
  },
  success: function(data) {
      location.reload();

public void savePerformanceActivity(string prodCode, string uid, string comm, string cat, string CpdActId, string act, string point, string date, string dec, string usersName ,string cpdstream,string filename)
    {
        Global DLdb = new Global();
        DLdb.DB_Connect();


        string json = "";
        string declaration = "";
        if (dec=="on")
        {
            declaration = "1";
        }
        else
        {
            declaration = "0";
        }

        DLdb.RS.Open();
        DLdb.SQLST.CommandText = "insert into Assessments (UserID,Category,CPDActivityID,Activity,ProductCode,NoPoints,CertificateDate,Comment,Declaration,CPD_Stream) values (@UserID,@Category,@CPDActivityID,@Activity,@ProductCode,@NoPoints,@CertificateDate,@Comment,@Declaration,@cpdstream)";
        DLdb.SQLST.Parameters.AddWithValue("UserID", uid.ToString());
        DLdb.SQLST.Parameters.AddWithValue("Category", cat.ToString());
        DLdb.SQLST.Parameters.AddWithValue("CPDActivityID", CpdActId.ToString());
        DLdb.SQLST.Parameters.AddWithValue("Activity", act.ToString());
        DLdb.SQLST.Parameters.AddWithValue("ProductCode", prodCode.ToString());
        DLdb.SQLST.Parameters.AddWithValue("NoPoints", point.ToString());
        DLdb.SQLST.Parameters.AddWithValue("CertificateDate", date.ToString());
        DLdb.SQLST.Parameters.AddWithValue("Comment", comm.ToString());
        DLdb.SQLST.Parameters.AddWithValue("Declaration", declaration.ToString());
        DLdb.SQLST.Parameters.AddWithValue("cpdstream", cpdstream.ToString());
        DLdb.SQLST.Parameters.AddWithValue("Attachment", filename.ToString());

        DLdb.SQLST.CommandType = CommandType.Text;
        DLdb.SQLST.Connection = DLdb.RS;
        SqlDataReader theSqlDataReader = DLdb.SQLST.ExecuteReader();

        if (theSqlDataReader.IsClosed) theSqlDataReader.Close();
        DLdb.SQLST.Parameters.RemoveAt(0);
        DLdb.SQLST.Parameters.RemoveAt(0);
        DLdb.SQLST.Parameters.RemoveAt(0);