C# と VB.NET の質問掲示板

☆やりたいこと
ExcelVBAからSendMessageで、プロセス間通信を行いたい

☆問題
・C#アプリ間(同一アプリ・別アプリ)は行えています
・ExcelVBA→C#の場合、WndProcのメッセージID振り分け直後にブレークをしてもキャッチ出来ない

☆環境
・Win7 x64
・Excel 2007
・VS 2012

☆仕様
・WM_COPYDATAメッセージを利用して、構造体の受け渡しを行う。(dwDataの値により型を指定)
・上記の検証として、文字列(Unicode)の受け渡しを行う。(dwData=0)

☆注意点
・FindWindow及び、SendMessageはAではなくW
・APIの型はStringやAnyではなくLongにし、StrPtrやVarPtrを使用
・C#のコンストラクタで出力しているウインドウハンドルと、ExcelのA2セルの値は10進で同一の為FindWindowは正常

☆C#

        public WinProc(AppSetting app)
        {
            InitializeComponent();

            this.Text = app.APIWindowName;
            this.textBox1.Text = "";

#if DEBUG
            textBox1.Text += string.Format("{0:yyyy/MM/dd HH:mm:ss} {1}{2}", DateTime.Now, this.Handle.ToString(), System.Environment.NewLine);
#endif
        }

        public delegate void receiveMsgHandler(object sender, receiveMsgEventArgs e);
        public event receiveMsgHandler recMsg;

        public void OnReceiveMsg(receiveMsgEventArgs e)
        {
            if (recMsg != null)
            {
                recMsg(this, e);
            }
        }

        public struct COPYDATASTRUCT
        {
            public IntPtr dwData;
            public UInt32 cbData;
            public IntPtr lpData;
        }
        public const int WM_COPYDATA = 0x4A;
        public const int WM_USER = 0x400;
        public const int WM_SETTEXT = 0xC;
        protected override void WndProc(ref Message m)
        {
            switch (m.Msg)
            {
                case WM_COPYDATA:
                    {
                        // 受信データ
                        COPYDATASTRUCT data = (COPYDATASTRUCT)Marshal.PtrToStructure(m.LParam, typeof(COPYDATASTRUCT));

                        //String msg = Marshal.PtrToStringUni(data.lpData);
                        byte[] bytes = new byte[data.cbData];
                        Marshal.Copy(data.lpData, bytes, 0, (int)data.cbData);
                        string msg = Encoding.Unicode.GetString(bytes);

                        // イベント
                        OnReceiveMsg(new receiveMsgEventArgs(msg));

#if DEBUG
                        textBox1.Text += string.Format("{0:yyyy/MM/dd HH:mm:ss} {1}{2}", DateTime.Now, msg, System.Environment.NewLine);
#endif
                        m.Result = new IntPtr(1);
                        break;
                    }

            }
            base.WndProc(ref m);
        }

☆Excel VBA(標準モジュール)
Option Explicit
Public Declare Function FindWindow Lib "User32.dll" Alias "FindWindowW" _
        (ByVal lpClassName As Long, _
         ByVal lpWindowName As Long) As Long
         
Public Declare Function SendMessage Lib "User32.dll" _
        Alias "SendMessageW" _
        (ByVal hWnd As Long, _
        ByVal Msg As Long, _
        ByVal wParam As Long, _
        ByVal lParam As Long) As Long

Public Type COPYDATASTRUCT
    dwData As Long
    cbData As Long
    lpData As Long
End Type

Public Const WM_COPYDATA As Integer = &H4A
Public Const WM_USER As Integer = &H400

☆Excel VBA(テストシート)
Option Explicit
Private Sub CommandButton1_Click()
    SendMsg (Sheet1.Range("D5").Value)
End Sub

Private Sub SendMsg(Msg As String)
    Dim ret As Long

    Dim hWnd As Long: hWnd = 0
    Dim sClass As String: sClass = vbNullString
    Dim sWindow As String: sWindow = "ReceiverMsg"
        
    Dim data As COPYDATASTRUCT
    Dim MsgBytes() As Byte

    hWnd = FindWindow(StrPtr(sClass), StrPtr(sWindow))
    If (hWnd = 0) Then
        MsgBox "起動してください"
        Exit Sub
    End If
    
    ' debug
    Sheet1.Range("A2").Value = hWnd
    
    MsgBytes = StrConv(Msg, vbUnicode)
    
    data.dwData = 0
    data.lpData = VarPtr(MsgBytes(1))
    data.cbData = UBound(MsgBytes)
    
    ret = SendMessage(hWnd, WM_COPYDATA, Me.Application.hWnd, VarPtr(data))
    
    ' debug
    Sheet1.Range("A1").Value = ret

End Sub

☆
不足が無いようにしたつもりですが、VB6ライクな言語(及びAPIの使用)は久しぶりのため
根本的な勘違いがあるかもしれませんが、よろしくお願いします。

解決コードです。

・No65680の魔界の仮面弁士さんの指摘により、C#側も修正(Pascal形式の型名・イベントハンドラーのジェネリク化)しています。
・標準モジュールは修正ありません。

☆Excel VBA(テストシート)
Option Explicit

Private Sub CommandButton1_Click()
    Call SendMsg(Sheet1.Range("D5").Value)
End Sub

Private Sub SendMsg(ByVal Msg As String)
    Dim ret As Long

    Dim hWnd As Long: hWnd = 0
    Dim sClass As String: sClass = vbNullString
    Dim sWindow As String: sWindow = "ReceiverMsg"
        
    Dim data As COPYDATASTRUCT
    Dim MsgBytes() As Byte

    If (Len(Msg) = 0) Then
        MsgBox "送信文が未入力"
        Exit Sub
    End If

    hWnd = FindWindow(StrPtr(sClass), StrPtr(sWindow))
    If (hWnd = 0) Then
        MsgBox "起動してください"
        Exit Sub
    End If
    
    ' debug
    Sheet1.Range("A2").Value = hWnd
    
    'MsgBytes = StrConv(Msg, vbUnicode)
    MsgBytes = Msg  ' StringのExcel内部文字コードはUnicode
    
    data.dwData = 0
    data.lpData = VarPtr(MsgBytes(LBound(MsgBytes)))
    data.cbData = UBound(MsgBytes) - LBound(MsgBytes) + 1   ' +1は終端文字列 vbNullChar を指すものでは無い
    
    ret = SendMessage(hWnd, WM_COPYDATA, Me.Application.hWnd, VarPtr(data))
    
    ' debug
    Sheet1.Range("A1").Value = ret

End Sub