Trouble with mouse click

[Morten Snedker]

If I have a number of random applications open, move the mouse cursor
to a given position and do a click, the application gets the focus.

That is what this simple code should illustrate:

Dim pt As Point
Dim wnd As IntPtr

Const WM_LBUTTONUP = &H202 '//LButton up
Const WM_LBUTTONDOWN = &H201 '//LButton down

pt.X = 450
pt.Y = 200

Windows.Forms.C ursor.Position = pt

wnd = WindowFromPoint (pt.X, pt.Y)
Call SendMessage(wnd , WM_LBUTTONDOWN, 0, 0&)
Call SendMessage(wnd , WM_LBUTTONUP, 0, 0&)


It moves the cursor, but the application beneith doesn't get focus, as
it would had i clicked on that position manually. What am I missing
out on?

Regards /Snedker

[Chris Dunaway]

Re: Trouble with mouse click

Morten Snedker wrote:

If I have a number of random applications open, move the mouse cursor
to a given position and do a click, the application gets the focus.
>
That is what this simple code should illustrate:
>
Dim pt As Point
Dim wnd As IntPtr
>
Const WM_LBUTTONUP = &H202 '//LButton up
Const WM_LBUTTONDOWN = &H201 '//LButton down
>
pt.X = 450
pt.Y = 200
>
Windows.Forms.C ursor.Position = pt
>
wnd = WindowFromPoint (pt.X, pt.Y)
Call SendMessage(wnd , WM_LBUTTONDOWN, 0, 0&)
Call SendMessage(wnd , WM_LBUTTONUP, 0, 0&)
>
>
It moves the cursor, but the application beneith doesn't get focus, as
it would had i clicked on that position manually. What am I missing
out on?
>

I suggest you fire up Spy++ and then test your scenario again. When
you click on an application, besides the mouse messages, there are
other messages sent, such as WM_ACTIVATE.

[teslar91@hotmail.com]

Re: Trouble with mouse click

If this is a continuation of our other thread - you didn't mention you
wanted it to receive focus too, just that you wanted it clicked and
without moving the mouse. :)

Chris' reply is correct.

But if the mouse pointer is in, or will be moved to, the proper
location, this is much easier:

Declare Sub mouse_event Lib "user32" (ByVal dwFlags As Int32, ByVal dX
As Int32, ByVal dy As Int32, ByVal cButtons As Int32, ByVal dwExtraInfo
As Int32)

mouse_event MOUSEEVENTF_LEF TDOWN + MOUSEEVENTF_LEF TUP, 0, 0, 0, 0

[rvalstar@hotmail.com]

Re: Trouble with mouse click

As Tesla... suggests indirectly, there are limited ways to simulate
mouse events in Windows. We have both mouse_events (deprecated) and
SendInput -- neither of which are managed code.

I have searched the net at length and attacked this "simple" problem
for many hours so I'm hoping my efforts will pay off for you.

This is a VB.NET 2005 test bed solution that allows you to play with
mouse_event, SendInput, and OnMouse... techniques. The OnMouse...
approach has yet to yield fruits. Either other approach (comment out
the other 2; uncomment the METHOD desired) work quite well.

This example expects a form called frmMain, a picture box called
picClick, three buttons: (btnClickStart, btnClick, btnScreen), and a
multi-line text box called txtResults.

This is an amalgam primarily based on
http://vb-helper.com/howto_move_click_mouse.html and
http://www.vbforums.com/showthread.php?t=398899 -- I'm trying to update
http://www.pinvoke.net/ to share this information.

Also, this code shows how to simulate a "union struct" in VB.NET -- I
was pleased to figure this out.

Rick Valstar
Star Consulting
r + last name + at + gmail + dot + com

Here's the code:

Option Explicit On

Imports System.Runtime. InteropServices

Public Class frmMain
'Const METHOD As String = "mouse_even t"
'Const METHOD As String = "OnMouse"
Const METHOD As String = "SendInput"

Const INPUT_MOUSE As Int32 = 0
Const INPUT_KEYBOARD As Int32 = 1
Const INPUT_HARDWARE As Int32 = 2

Const MOUSEEVENTF_MOV E As Int32 = &H1 ' mouse move
Const MOUSEEVENTF_LEF TDOWN As Int32 = &H2 ' left button down
Const MOUSEEVENTF_LEF TUP As Int32 = &H4 ' left button up
Const MOUSEEVENTF_RIG HTDOWN As Int32 = &H8 ' right button down
Const MOUSEEVENTF_RIG HTUP As Int32 = &H10 ' right button up
Const MOUSEEVENTF_MID DLEDOWN As Int32 = &H20 ' middle button down
Const MOUSEEVENTF_MID DLEUP As Int32 = &H40 ' middle button up
Const MOUSEEVENTF_ABS OLUTE As Int32 = &H8000 ' absolute move
Const MOUSEEVENTF_WHE EL As Int32 = &H800 ' wheel button rolled

Private Structure MOUSEINPUT
Dim dx As Int32
Dim dy As Int32
Dim mouseData As Int32
Dim dwFlags As Int32
Dim time As Int32
Dim dwExtraInfo As IntPtr
End Structure

Private Structure KEYBDINPUT
Dim wVk As Int16
Dim wScan As Int16
Dim dwFlags As Int32
Dim time As Int32
Dim dwExtraInfo As IntPtr
End Structure

Private Structure HARDWAREINPUT
Dim uMsg As Int32
Dim wParamL As Int16
Dim wParamH As Int16
End Structure

<StructLayout(L ayoutKind.Expli cit)_
Private Structure INPUT
<FieldOffset(0) Dim dwType As Int32
' simulate a union struct (C) or a variant record (Pascal)
<FieldOffset(4) Dim mi As MOUSEINPUT
<FieldOffset(4) Dim ki As KEYBDINPUT
<FieldOffset(4) Dim hi As HARDWAREINPUT
End Structure

Private Declare Auto Sub mouse_event Lib "user32.dll " (ByVal
dwFlags As Int32, ByVal dx As Int32, ByVal dy As Int32, ByVal cButtons
As Int32, ByVal dwExtraInfo As IntPtr)

<DllImport("use r32.dll", SetLastError:=T rue)_
Private Shared Function SendInput(ByVal nInputs As Int32, ByRef
pInputs As INPUT, ByVal cbSize As Int32) As Int32
End Function

Private Declare Auto Sub SetLastError Lib "kernel32.d ll" (ByVal
dwErrCode As Int32)

Sub ClickMouse(ByVa l MouseButton As Integer)
Dim inputevents As New INPUT

inputevents.mi. dx = 0
inputevents.mi. dy = 0
inputevents.mi. mouseData = 0
inputevents.mi. dwFlags = MouseButton
inputevents.mi. time = 0
inputevents.dwT ype = INPUT_MOUSE

SetLastError(0)
Dim result As Integer = SendInput(1, inputevents,
Marshal.SizeOf( GetType(INPUT)) )
Dim lasterror As Integer = Marshal.GetLast Win32Error

Debug.WriteLine ("Result: " & result)
Debug.WriteLine ("LastError: " & lasterror & " " & New
System.Componen tModel.Win32Exc eption(lasterro r).Message)
End Sub

Sub btnClickStart_C lick(ByVal sender As System.Object, ByVal e As
System.EventArg s) Handles btnClickStart.C lick
txtResults.Appe ndText("***** btnClickStart *****" & vbCrLf)

'move mouse to the start button
Dim pt As New System.Drawing. Point(20,
Screen.PrimaryS creen.Bounds.He ight - 20)
'Dim pt As Point = picClicker.Poin tToScreen(New
Point(picClicke r.ClientRectang le.Width / 2,
picClicker.Clie ntRectangle.Hei ght / 2))

Debug.WriteLine ("pt " & pt.X & " " & pt.Y)

System.Windows. Forms.Cursor.Po sition = pt
Windows.Forms.A pplication.DoEv ents()

ClickMouse(MOUS EEVENTF_LEFTDOW N) 'press left button
ClickMouse(MOUS EEVENTF_LEFTUP) 'release left button
End Sub

Private Sub btnClick_Click( ByVal eventSender As System.Object,
ByVal eventArgs As System.EventArg s) Handles btnClick.Click
Dim cur_x As Single
Dim cur_y As Single
Dim dest_x As Single
Dim dest_y As Single

txtResults.Appe ndText("***** btnClick *****" & vbCrLf)

' mouse_event moves in a coordinate system where (0, 0) is in
the upper left corner and (65535,65535) is in the lower right corner.

' Get the current mouse coordinates and convert them into this
new system.
cur_x = System.Windows. Forms.Cursor.Po sition.X * 65535 /
System.Windows. Forms.Screen.Pr imaryScreen.Bou nds.Width
cur_y = System.Windows. Forms.Cursor.Po sition.Y * 65535 /
System.Windows. Forms.Screen.Pr imaryScreen.Bou nds.Height

' Convert the coordinates of the center of the picClicker
PictureBox into this new system.
Dim pt As Point = picClicker.Poin tToScreen(New
Point(picClicke r.ClientRectang le.Width / 2,
picClicker.Clie ntRectangle.Hei ght / 2))
'Dim pt As New System.Drawing. Point(20,
Screen.PrimaryS creen.Bounds.He ight - 20)

dest_x = pt.X * 65535 /
System.Windows. Forms.Screen.Pr imaryScreen.Bou nds.Width
dest_y = pt.Y * 65535 /
System.Windows. Forms.Screen.Pr imaryScreen.Bou nds.Height

txtResults.Appe ndText("From " &
System.Windows. Forms.Cursor.Po sition.X & " " &
System.Windows. Forms.Cursor.Po sition.Y & " to " & pt.X & " " & pt.Y &
vbCrLf)
txtResults.Appe ndText("From " & cur_x & " " & cur_y & " to " &
dest_x & " " & dest_y & vbCrLf)

' Move the mouse to its final destination and click it.
Select Case METHOD
Case "OnMouse"
System.Windows. Forms.Cursor.Po sition = pt
Windows.Forms.A pplication.DoEv ents()

'Dim eMouseMove As New
System.Windows. Forms.MouseEven tArgs(Windows.F orms.MouseButto ns.None, 0,
pt.X, pt.Y, 0)

'Me.OnMouseMove (eMouseMove)

Dim eMouseButton As New
System.Windows. Forms.MouseEven tArgs(Windows.F orms.MouseButto ns.Left, 1,
0, 0, 0)

Me.OnMouseDown( eMouseButton)
Me.OnMouseUp(eM ouseButton)

Case "mouse_even t"
mouse_event(MOU SEEVENTF_ABSOLU TE + MOUSEEVENTF_MOV E +
MOUSEEVENTF_LEF TDOWN + MOUSEEVENTF_LEF TUP, dest_x, dest_y, 0, 0)

Case "SendInput"
Dim pInputs(0 To 2) As INPUT

With pInputs(0)
.dwType = INPUT_MOUSE
.mi.dx = dest_x
.mi.dy = dest_y
.mi.mouseData = 0
.mi.dwFlags = MOUSEEVENTF_ABS OLUTE +
MOUSEEVENTF_MOV E
.mi.time = 0
.mi.dwExtraInfo = IntPtr.Zero
End With

With pInputs(1)
.dwType = INPUT_MOUSE
.mi.dx = 0
.mi.dy = 0
.mi.mouseData = 0
.mi.dwFlags = MOUSEEVENTF_LEF TDOWN
.mi.time = 0
.mi.dwExtraInfo = IntPtr.Zero
End With

With pInputs(2)
.dwType = INPUT_MOUSE
.mi.dx = 0
.mi.dy = 0
.mi.mouseData = 0
.mi.dwFlags = MOUSEEVENTF_LEF TUP
.mi.time = 0
.mi.dwExtraInfo = IntPtr.Zero
End With

'System.Windows .Forms.Cursor.P osition = pt
'Windows.Forms. Application.DoE vents()

'Debug.WriteLin e("Size: " & Marshal.SizeOf( pInputs(0))
& " " & Marshal.SizeOf( GetType(INPUT)) )

SetLastError(0)
Debug.WriteLine ("Result: " & SendInput(3, pInputs(0),
Marshal.SizeOf( GetType(INPUT)) ))
Debug.WriteLine ("LastError: " &
Marshal.GetLast Win32Error & " " & New
System.Componen tModel.Win32Exc eption(Marshal. GetLastWin32Err or).Message)

'SetLastError(0 )
'Debug.WriteLin e("Result: " & SendInput(1, pInputs(1),
Marshal.SizeOf( GetType(INPUT)) ))
'Debug.WriteLin e("LastError: " &
Marshal.GetLast Win32Error & " " & New
System.Componen tModel.Win32Exc eption(Marshal. GetLastWin32Err or).Message)

'SetLastError(0 )
'Debug.WriteLin e("Result: " & SendInput(1, pInputs(2),
Marshal.SizeOf( GetType(INPUT)) ))
'Debug.WriteLin e("LastError: " &
Marshal.GetLast Win32Error & " " & New
System.Componen tModel.Win32Exc eption(Marshal. GetLastWin32Err or).Message)

Case Else
Beep()
End Select

'Windows.Forms. Application.DoE vents()
'My.Application .DoEvents()
End Sub

Private Sub btnScreen_Click (ByVal sender As System.Object, ByVal e
As System.EventArg s) Handles btnScreen.Click
Dim I As Integer
Dim Screens() As System.Windows. Forms.Screen =
System.Windows. Forms.Screen.Al lScreens

txtResults.Appe ndText("***** btnScreen *****" & vbCrLf)

For I = 0 To Screens.GetUppe rBound(0)
txtResults.Appe ndText("Device Name: " +
Screens(I).Devi ceName & vbCrLf)
txtResults.Appe ndText("Bounds: " +
Screens(I).Boun ds.ToString() & vbCrLf)
txtResults.Appe ndText("Type: " +
Screens(I).GetT ype().ToString( ) & vbCrLf)
txtResults.Appe ndText("Working Area: " +
Screens(I).Work ingArea.ToStrin g() & vbCrLf)
txtResults.Appe ndText("Primary Screen: " +
Screens(I).Prim ary.ToString() & vbCrLf)
Next I
End Sub

Private Sub picClicker_Clic k(ByVal eventSender As System.Object,
ByVal eventArgs As System.EventArg s) Handles picClicker.Clic k
txtResults.Appe ndText("picClic ker_Click" & vbCrLf)
End Sub

Private Sub picClicker_Mous eDown(ByVal sender As System.Object,
ByVal e As System.Windows. Forms.MouseEven tArgs) Handles
picClicker.Mous eDown
txtResults.Appe ndText("picClic ker_MouseDown (" & e.X & ", " &
e.Y & ")" & vbCrLf)
End Sub

Private Sub picClicker_Mous eUp(ByVal sender As System.Object, ByVal
e As System.Windows. Forms.MouseEven tArgs) Handles picClicker.Mous eUp
txtResults.Appe ndText("picClic ker_MouseUp (" & e.X & ", " & e.Y
& ")" & vbCrLf)
End Sub

Private Sub frmMain_Click(B yVal sender As Object, ByVal e As
System.EventArg s) Handles Me.Click
txtResults.Appe ndText("frmMain _Click" & vbCrLf)
End Sub

Private Sub frmMain_MouseDo wn(ByVal sender As Object, ByVal e As
System.Windows. Forms.MouseEven tArgs) Handles Me.MouseDown
txtResults.Appe ndText("frmMain _MouseDown (" & e.X & ", " & e.Y
& ")" & vbCrLf)
End Sub

Private Sub frmMain_MouseUp (ByVal sender As Object, ByVal e As
System.Windows. Forms.MouseEven tArgs) Handles Me.MouseUp
txtResults.Appe ndText("frmMain _MouseUp (" & e.X & ", " & e.Y &
")" & vbCrLf)
End Sub
End Class