Полученное SMS не отображается в приложении С#

У меня есть приложение С#, которое получает SMS-сообщения и отображает их.

Когда я отправляю SMS без этой программы и с помощью GSM-модема, SMS сохраняется в GSM-модеме. Когда я запускаю приложение и нажимаю "прочитать SMS", оно показывает мне только те SMS, которые были ранее получены, и которые я уже видел в GSM-модеме. Новое смс, которое я отправил недавно, не видно.

Программа просто показывает СМС которые читаются с модема. Что сделать, чтобы полученное СМС сразу отображалось в программе?

Код:

public Receive()
{
    //
    // Required for Windows Form Designer support
    //
    InitializeComponent();

    //
    // TODO: Add any constructor code after InitializeComponent call
    //
}

/// <summary>
/// Clean up any resources being used.
/// </summary>
protected override void Dispose( bool disposing )
{
    if( disposing )
    {
        if(components != null)
        {
            components.Dispose();
        }
    }
    base.Dispose( disposing );
}

#region Windows Form Designer generated code
/// <summary>
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
/// </summary>
private void InitializeComponent()
{
    this.btnReadMessage = new System.Windows.Forms.Button();
    this.rbMessagePhone = new System.Windows.Forms.RadioButton();
    this.rbMessageSIM = new System.Windows.Forms.RadioButton();
    this.txtOutput = new System.Windows.Forms.TextBox();
    this.groupBox1 = new System.Windows.Forms.GroupBox();
    this.dataGrid1 = new System.Windows.Forms.DataGrid();
    this.groupBox1.SuspendLayout();
    ((System.ComponentModel.ISupportInitialize)(this.dataGrid1)).BeginInit();
    this.SuspendLayout();
    //
    // btnReadMessage
    //
    this.btnReadMessage.FlatStyle = System.Windows.Forms.FlatStyle.System;
    this.btnReadMessage.Location = new System.Drawing.Point(192, 80);
    this.btnReadMessage.Name = "btnReadMessage";
    this.btnReadMessage.Size = new System.Drawing.Size(112, 24);
    this.btnReadMessage.TabIndex = 17;
    this.btnReadMessage.Text = "Read All Messages";
    this.btnReadMessage.Click += new System.EventHandler(this.btnReadMessage_Click);
    //
    // rbMessagePhone
    //
    this.rbMessagePhone.FlatStyle = System.Windows.Forms.FlatStyle.System;
    this.rbMessagePhone.Location = new System.Drawing.Point(16, 56);
    this.rbMessagePhone.Name = "rbMessagePhone";
    this.rbMessagePhone.Size = new System.Drawing.Size(64, 24);
    this.rbMessagePhone.TabIndex = 25;
    this.rbMessagePhone.Text = "Phone";
    //
    // rbMessageSIM
    //
    this.rbMessageSIM.Checked = true;
    this.rbMessageSIM.FlatStyle = System.Windows.Forms.FlatStyle.System;
    this.rbMessageSIM.Location = new System.Drawing.Point(16, 24);
    this.rbMessageSIM.Name = "rbMessageSIM";
    this.rbMessageSIM.Size = new System.Drawing.Size(64, 24);
    this.rbMessageSIM.TabIndex = 24;
    this.rbMessageSIM.TabStop = true;
    this.rbMessageSIM.Text = "SIM";
    //
    // txtOutput
    //
    this.txtOutput.Location = new System.Drawing.Point(8, 304);
    this.txtOutput.Multiline = true;
    this.txtOutput.Name = "txtOutput";
    this.txtOutput.ScrollBars = System.Windows.Forms.ScrollBars.Vertical;
    this.txtOutput.Size = new System.Drawing.Size(448, 144);
    this.txtOutput.TabIndex = 57;
    this.txtOutput.Text = "";
    //
    // groupBox1
    //
    this.groupBox1.Controls.Add(this.rbMessageSIM);
    this.groupBox1.Controls.Add(this.rbMessagePhone);
    this.groupBox1.Location = new System.Drawing.Point(8, 8);
    this.groupBox1.Name = "groupBox1";
    this.groupBox1.Size = new System.Drawing.Size(176, 96);
    this.groupBox1.TabIndex = 58;
    this.groupBox1.TabStop = false;
    this.groupBox1.Text = "Message Storage";
    //
    // dataGrid1
    //
    this.dataGrid1.DataMember = "";
    this.dataGrid1.HeaderForeColor = System.Drawing.SystemColors.ControlText;
    this.dataGrid1.Location = new System.Drawing.Point(8, 120);
    this.dataGrid1.Name = "dataGrid1";
    this.dataGrid1.Size = new System.Drawing.Size(448, 176);
    this.dataGrid1.TabIndex = 59;
    //
    // Receive
    //
    this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
    this.ClientSize = new System.Drawing.Size(464, 454);
    this.Controls.Add(this.dataGrid1);
    this.Controls.Add(this.groupBox1);
    this.Controls.Add(this.txtOutput);
    this.Controls.Add(this.btnReadMessage);
    this.Name = "Receive";
    this.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen;
    this.Text = "Read Messages";
    this.Load += new System.EventHandler(this.Receive_Load);
    this.groupBox1.ResumeLayout(false);
    ((System.ComponentModel.ISupportInitialize)(this.dataGrid1)).EndInit();
    this.ResumeLayout(false);

}
#endregion

private void btnReadMessage_Click(object sender, System.EventArgs e)
{
    Cursor.Current = Cursors.WaitCursor;
    string storage = GetMessageStorage();

    try
    {
        // Read all SMS messages from the storage

        DecodedShortMessage[] messages = CommSetting.comm.ReadMessages(PhoneMessageStatus.All,storage );
        foreach(DecodedShortMessage message in messages)
        {
            Output(string.Format("Message status = {0}, Location = {1}/{2}",
                StatusToString(message.Status),    message.Storage, message.Index));
            ShowMessage(message.Data);
            Output("");
        }
        Output(string.Format("{0,9} messages read.", messages.Length.ToString()));
        Output("");
    }
    catch(Exception ex)
    {
        MessageBox.Show(ex.Message);
    }

    Cursor.Current = Cursors.Default;
}


private void BindGrid(SmsPdu pdu)
{

    DataRow dr=dt.NewRow();
    SmsDeliverPdu data = (SmsDeliverPdu)pdu;

    dr[0]=data.OriginatingAddress.ToString();
    dr[1]=data.SCTimestamp.ToString();
    dr[2]=data.UserDataText;
    dt.Rows.Add(dr);

    dataGrid1.DataSource=dt;
}

private void ShowMessage(SmsPdu pdu)
{
    if (pdu is SmsSubmitPdu)
    {
        // Stored (sent/unsent) message
        SmsSubmitPdu data = (SmsSubmitPdu)pdu;
        Output("SENT/UNSENT MESSAGE");
        Output("Recipient: " + data.DestinationAddress);
        Output("Message text: " + data.UserDataText);
        Output("-------------------------------------------------------------------");
        return;
    }
    if (pdu is SmsDeliverPdu)
    {
        // Received message
        SmsDeliverPdu data = (SmsDeliverPdu)pdu;
        Output("RECEIVED MESSAGE");
        Output("Sender: " + data.OriginatingAddress);
        Output("Sent: " + data.SCTimestamp.ToString());
        Output("Message text: " + data.UserDataText);
        Output("-------------------------------------------------------------------");

        BindGrid(pdu);

        return;
    }
    if (pdu is SmsStatusReportPdu)
    {
        // Status report
        SmsStatusReportPdu data = (SmsStatusReportPdu)pdu;
        Output("STATUS REPORT");
        Output("Recipient: " + data.RecipientAddress);
        Output("Status: " + data.Status.ToString());
        Output("Timestamp: " + data.DischargeTime.ToString());
        Output("Message ref: " + data.MessageReference.ToString());
        Output("-------------------------------------------------------------------");
        return;
    }
    Output("Unknown message type: " + pdu.GetType().ToString());
}


private string StatusToString(PhoneMessageStatus status)
{
    // Map a message status to a string
    string ret;
    switch(status)
    {
        case PhoneMessageStatus.All:
            ret = "All";
            break;
        case PhoneMessageStatus.ReceivedRead:
            ret = "Read";
            break;
        case PhoneMessageStatus.ReceivedUnread:
            ret = "Unread";
            break;
        case PhoneMessageStatus.StoredSent:
            ret = "Sent";
            break;
        case PhoneMessageStatus.StoredUnsent:
            ret = "Unsent";
            break;
        default:
            ret = "Unknown (" + status.ToString() + ")";
            break;
    }
    return ret;
}


private string GetMessageStorage()
{
    string storage = string.Empty;
    if (rbMessageSIM.Checked)
        storage = PhoneStorageType.Sim;
    if (rbMessagePhone.Checked)
        storage = PhoneStorageType.Phone;
    if (storage.Length == 0)
        throw new ApplicationException("Unknown message storage.");
    else
        return storage;
}


private void Output(string text)
{
    if (this.txtOutput.InvokeRequired)
    {
        SetTextCallback stc = new SetTextCallback(Output);
        this.Invoke(stc, new object[] { text });
    }
    else
    {
        txtOutput.AppendText(text);
        txtOutput.AppendText("\r\n");
    }
}


private void Receive_Load(object sender, System.EventArgs e)
{
    dt.Columns.Add("Sender",typeof(string));
    dt.Columns.Add("Time",typeof(string));
    dt.Columns.Add("Message",typeof(string));
}

private void Output(string text, params object[] args)
{
    string msg = string.Format(text, args);
    Output(msg);
}