VB SendMessage向其他程序窗口发送字符串消息实例

'先创建一个文本文档,命名为： 1.txt

'     然后打开测试。。。
Private Const WM_SETTEXT = &HC

Private Declare Function SendMessage _
                Lib "user32" _
                Alias "SendMessageA" (ByVal hwnd As Long, _
                                      ByVal wMsg As Long, _
                                      ByVal wParam As Long, _
                                      lParam As Any) As Long
Private Declare Function FindWindow _
                Lib "user32" _
                Alias "FindWindowA" (ByVal lpClassName As String, _
                                     ByVal lpWindowName As String) As Long
Private Declare Function GetDlgItem _
                Lib "user32" (ByVal hDlg As Long, _
                              ByVal nIDDlgItem As Long) As Long

Private Sub Command1_Click()
    Dim s               As String
    Dim FT_hWnd         As Long
    Dim ID_Control_hWnd As Long
    s = "你好"
    FT_hWnd = FindWindow(vbNullString, "1.txt - 记事本")

    If FT_hWnd = 0 Then
        MsgBox "False", vbInformation, "Title"
        End
    End If

    ID_Control_hWnd = GetDlgItem(FT_hWnd, &HF)
    SendMessage ID_Control_hWnd, WM_SETTEXT, 0, ByVal s

End Sub