Emulate Left Mouse Button

[Shivan]

This is for a school project. I'm building a program that receives a number from the serial port. If that number is number 4, for example, it simulates the left mouse button. So, if the mouse is over a command button, and the serial port receives the number 4, the command button will be selected (activated), as if it was clicked with the mouse. So far, all I can do is receiving that number from the serial port, through a microcontroller. The number is well sent to the PC, I've tested it. So far so good. What I can't do is simulating the mouse click, the left button. I've searched through Visual Basic 6.0 help, but can't figure out what to do! Should I use an API?? Can someone help me?? Thank you.

P.S.: Here is my program. The toggle button is to open/close the serial port. I'm reading the buffer from the serial port in a text box (more simple). Then I compare it to number 4. If it's true, how do I simulate the mouse click?? It will help if someone knows how to simulate if number 4 is pressed from keyboard, for example. The objective is to simulate the left mouse button...without using the mouse!!

[Vlatko]

'Before you start this program, I suggest you save everything that wasn't saved yet.
Private Declare Sub mouse_event Lib "user32" (ByVal dwFlags As Long, ByVal dx As Long, ByVal dy As Long, ByVal cButtons As Long, ByVal dwExtraInfo As Long)
Const MOUSEEVENTF_LEFTDOWN = &H2
Const MOUSEEVENTF_LEFTUP = &H4
Const MOUSEEVENTF_MIDDLEDOWN = &H20
Const MOUSEEVENTF_MIDDLEUP = &H40
Const MOUSEEVENTF_MOVE = &H1
Const MOUSEEVENTF_ABSOLUTE = &H8000
Const MOUSEEVENTF_RIGHTDOWN = &H8
Const MOUSEEVENTF_RIGHTUP = &H10
Private Sub Form_Activate()
Do
'Simulate a mouseclick on the cursor's position
mouse_event MOUSEEVENTF_LEFTDOWN Or MOUSEEVENTF_LEFTUP, 0&, 0&, cButt, dwEI
DoEvents
Loop
End Sub

Private Declare Function PostMessage Lib "user32" Alias "PostMessageA" (ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, ByVal lParam As Long) As Long
Private Const WM_LBUTTONDOWN = &H201
Private Const WM_LBUTTONUP = &H202

Private Sub Command1_Click()
PostMessage mybutton.hwnd, WM_LBUTTONDOWN, 1, 0
PostMessage mybutton.hwnd, WM_LBUTTONUP, 1, 0
End Sub

[gwdash]

it shouldn't be too hard:

'Before you start this program, I suggest you save everything that wasn't saved yet.
Private Declare Sub mouse_event Lib "user32" (ByVal dwFlags As Long, ByVal dx As Long, ByVal dy As Long, ByVal cButtons As Long, ByVal dwExtraInfo As Long)
Const MOUSEEVENTF_LEFTDOWN = &H2
Const MOUSEEVENTF_LEFTUP = &H4
Const MOUSEEVENTF_MIDDLEDOWN = &H20
Const MOUSEEVENTF_MIDDLEUP = &H40
Const MOUSEEVENTF_MOVE = &H1
Const MOUSEEVENTF_ABSOLUTE = &H8000
Const MOUSEEVENTF_RIGHTDOWN = &H8
Const MOUSEEVENTF_RIGHTUP = &H10
Private Sub Form_Activate()
'KPD-Team 1998
'URL: http://www.allapi.net/
'E-Mail: KPDTeam@Allapi.net
Do
'Simulate a mouseclick On the cursor's position
mouse_event MOUSEEVENTF_LEFTDOWN Or MOUSEEVENTF_LEFTUP, 0&, 0&, cButt, dwEI
DoEvents
Loop
End Sub

Modify it to fit your needs.