Sample: ManagedDataRequest.vb

Article
06/26/2008

REM
REM VB.NET Managed Data Request sample
REM
REM Click on Connect to try and connect to a running version of FSX
REM Click on Request Data any number of times
REM Click on Disconnect to close the connection, and then you should
REM be able to click on Connect and restart the process
REM

Imports System
Imports System.Collections.Generic
Imports System.ComponentModel
Imports System.Data
Imports System.Drawing
Imports System.Text
Imports System.Windows.Forms

REM Add these two statements to all SimConnect clients
Imports Microsoft.FlightSimulator.SimConnect
Imports System.Runtime.InteropServices

Public Class ManagedDataRequest

    Dim fsx_simconnect As SimConnect

    REM User-defined win32 event
    Private Const WM_USER_SIMCONNECT As Integer = &H402;

    Enum StructDefinitions

        Struct1 = 1

    End Enum
    Enum DataRequests

        Request_1 = 1

    End Enum

    REM This is how you declare a data structure so that simconnect knows how to fill it/read it.

    <StructLayout(LayoutKind.Sequential, CharSet:=CharSet.Ansi, Pack:=1)> _
    Structure Struct1
        REM This is how you declare a fixed size string
        <MarshalAs(UnmanagedType.ByValTStr, SizeConst:=256)> _
        Public title As String
        Public latitude As Double
        Public longitude As Double
        Public altitude As Double

    End Structure
    REM Output text line number

    Dim line

    Public Sub New()

        REM This call is required by the Windows Form Designer.
        InitializeComponent()

        REM Add any initialization after the InitializeComponent() call.
        fsx_simconnect = Nothing
        line = 0
        SetButtons(True, False, False)

    End Sub

    Private Sub SetButtons(ByVal bConnect As Boolean, ByVal bRequest As Boolean, ByVal bDisconnect As Boolean)

        ButtonConnect.Enabled = bConnect
        ButtonRequest.Enabled = bRequest
        ButtonDisconnect.Enabled = bDisconnect

    End Sub

    Private Sub ButtonConnect_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles ButtonConnect.Click

        If fsx_simconnect Is Nothing Then

            Try
                fsx_simconnect = New SimConnect(" VB Managed Data Request", Me.Handle, WM_USER_SIMCONNECT, Nothing, 0)
                initDataRequest()
                DisplayText("Connection request sent ...")
                SetButtons(False, True, True)

            Catch ex As Exception
                DisplayText("Failed to connect")
            End Try

        Else
            DisplayText("Error - try again")
            closeConnection()
        End If

    End Sub
    Private Sub initDataRequest()

        REM Set up all the SimConnect related data definitions and event handlers

        REM listen to connect and quit msgs
        AddHandler fsx_simconnect.OnRecvOpen, New SimConnect.RecvOpenEventHandler(AddressOf fsx_simconnect_OnRecvOpen)
        AddHandler fsx_simconnect.OnRecvQuit, New SimConnect.RecvQuitEventHandler(AddressOf fsx_simconnect_OnRecvQuit)

        REM listen to exceptions
        AddHandler fsx_simconnect.OnRecvException, New SimConnect.RecvExceptionEventHandler(AddressOf fsx_simconnect_OnRecvException)

        REM define a data structure, note the last parameter, datumID must be different for each item

        fsx_simconnect.AddToDataDefinition(StructDefinitions.Struct1, "Title", "", Microsoft.FlightSimulator.SimConnect.SIMCONNECT_DATATYPE.STRING256, 0, 0)
        fsx_simconnect.AddToDataDefinition(StructDefinitions.Struct1, "Plane Latitude", "degrees", Microsoft.FlightSimulator.SimConnect.SIMCONNECT_DATATYPE.FLOAT64, 0, 1)
        fsx_simconnect.AddToDataDefinition(StructDefinitions.Struct1, "Plane Longitude", "degrees", Microsoft.FlightSimulator.SimConnect.SIMCONNECT_DATATYPE.FLOAT64, 0, 2)
        fsx_simconnect.AddToDataDefinition(StructDefinitions.Struct1, "Plane Altitude", "feet", Microsoft.FlightSimulator.SimConnect.SIMCONNECT_DATATYPE.FLOAT64, 0, 3)

        REM IMPORTANT: register it with the simconnect managed wrapper marshaller
        REM if you skip this step, you will only receive an int in the .dwData field.

        fsx_simconnect.RegisterDataDefineStruct(Of Struct1)(StructDefinitions.Struct1)

        REM catch a simobject data request
        AddHandler fsx_simconnect.OnRecvSimobjectDataBytype, New SimConnect.RecvSimobjectDataBytypeEventHandler(AddressOf fsx_simconnect_OnRecvSimobjectDataBytype)

    End Sub
    Private Sub fsx_simconnect_OnRecvOpen(ByVal sender As SimConnect, ByVal data As SIMCONNECT_RECV_OPEN)

        DisplayText("Connected to FSX")

    End Sub

    REM The case where the user closes FSX
    Private Sub fsx_simconnect_OnRecvQuit(ByVal sender As SimConnect, ByVal data As Microsoft.FlightSimulator.SimConnect.SIMCONNECT_RECV)

        DisplayText("FSX has exited")
        closeConnection()
        SetButtons(True, False, False)

    End Sub
    Private Sub fsx_simconnect_OnRecvException(ByVal sender As SimConnect, ByVal data As Microsoft.FlightSimulator.SimConnect.SIMCONNECT_RECV_EXCEPTION)

        DisplayText("Exception received: " + data.dwException.ToString())

    End Sub

    REM The case where the user closes the client
    Private Sub Form1_FormClosed(ByVal sender As Object, ByVal e As FormClosedEventArgs) Handles MyBase.FormClosed

        closeConnection()

    End Sub
    Private Sub fsx_simconnect_OnRecvSimobjectDataBytype(ByVal sender As SimConnect, ByVal data As SIMCONNECT_RECV_SIMOBJECT_DATA_BYTYPE)

        Select Case data.dwRequestID
            Case DataRequests.Request_1
                REM Cast the data input to the correct structure type
                Dim s1 As Struct1 = CType(data.dwData(0), Struct1)

                DisplayText("Title: " + s1.title)
                DisplayText("LLA:   " + s1.latitude.ToString("##0.00") + "  " + s1.longitude.ToString("##0.00") + "  " + s1.altitude.ToString("#####0.0"))

            Case Else
                DisplayText("Unknown request ID: " + data.dwRequestID.ToString())
        End Select

    End Sub

    Private Sub closeConnection()

        If fsx_simconnect IsNot Nothing Then
            fsx_simconnect.Dispose()
            fsx_simconnect = Nothing
            DisplayText("Connection closed")
        End If

    End Sub
    Private Sub ButtonDisconnect_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles ButtonDisconnect.Click

        closeConnection()
        SetButtons(True, False, False)

    End Sub

    Private Sub ButtonRequest_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles ButtonRequest.Click

        fsx_simconnect.RequestDataOnSimObjectType(DataRequests.Request_1, StructDefinitions.Struct1, 0, Microsoft.FlightSimulator.SimConnect.SIMCONNECT_SIMOBJECT_TYPE.USER)
        DisplayText("Data request sent ...")

    End Sub

    Private Sub DisplayText(ByVal text As String)

        Dim output As String

        output = line.ToString() + ": " + text + Environment.NewLine + RichResponses.Text

        RichResponses.Text = output

        line += 1

    End Sub
    REM Simconnect client will send a win32 message when there is
    REM a packet to process. ReceiveMessage must be called to
    REM trigger the events. This model keeps simconnect processing on the main thread.
    Protected Overrides Sub DefWndProc(ByRef m As Message)

        If m.Msg = WM_USER_SIMCONNECT Then

            If fsx_simconnect IsNot Nothing Then
                fsx_simconnect.ReceiveMessage()

            End If
        Else
            MyBase.DefWndProc(m)
        End If

    End Sub

End Class

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Sample: ManagedDataRequest.vb

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