I'm trying to pass text to a 3rd party program but running into a snag.
I have isolated the Class Handler ID inside my program,validated with the messagebox. However, when I try sending it text, I get a run time error.
Public Declare Function FindWindow Lib "user32.dll" Alias "FindWindowA" (ByVal lpClassName As String, ByVal lpWindowName As String) As Int32
Public Declare Function SendMessage Lib "user32.dll" Alias "SendMessageA" (ByVal hwnd As Int32, ByVal wMsg As Int32, ByVal wParam As Int32, ByVal lParam As Int32) As Int32
Public Declare Function FindWindowEx Lib "user32.dll" Alias "FindWindowExA" (ByVal hWnd1 As Int32, ByVal hWnd2 As Int32, ByVal lpsz1 As String, ByVal lpsz2 As String) As Int32
Dim hwnd As Integer
Dim hwindow2 As Integer
Dim main_view As Integer
Dim sub_window As Integer
Public Const WM_SETTEXT = &H0
And
Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
hwindow2 = FindWindow(vbNullString, "Trace")
main_view = FindWindowEx(hwindow2, 0&, "#32770", vbNullString)
System.Threading.Thread.Sleep(10)
sub_window = FindWindowEx(main_view, 0&, "Edit", vbNullString)
MessageBox.Show(main_view)
MessageBox.Show(sub_window)
Call SendMessage(sub_window, WM_SETTEXT, 0, "test")
End Sub
Any help would be appreciated.
Thanks
you might consider using PostMessage(), it is an asynchronous method and it won't wait for the response from the receiving end. while SendMessage method is synchronous, it 'does not return until the window procedure has processed the message'.
see suggestions from post here
it is also good to indicate the error message to better understand the problem.
Related
The Goal:
I am trying to create a Visual Basic program that will execute some code whenever any new program window is displayed on screen. Just for an easy to understand example: When I launch a program like File Explorer, I want a message box to be displayed when the window for File Explorer is displayed on screen.
The Problem:
Using the code I provided below, my desired outcome works correctly. However, it will also display a message box whenever something like a context menu is displayed as well. I do not want this. I only want a message box to be displayed whenever an actual program window is displayed. I've tried adding checks for checking if the window has 'minimize', 'maximize', and 'close' buttons. But after adding those checks, a message box no longer gets displayed at all, even with a window that has caption buttons, like File Explorer.
This is my code:
Private Declare Function GetForegroundWindow Lib "user32.dll" () As IntPtr
Declare Auto Function SetWinEventHook Lib "user32.dll" (ByVal eventMin As Integer, ByVal eventMax As Integer, ByVal hmodWinEventProc As IntPtr, ByVal lpfnWinEventProc As WinEventDelegate, ByVal idProcess As Integer, ByVal idThread As Integer, ByVal dwflags As Integer) As IntPtr
Declare Auto Function UnhookWinEvent Lib "user32.dll" (ByVal hWinEventHook As IntPtr) As Boolean
Delegate Sub WinEventDelegate(ByVal hWinEventHook As IntPtr, ByVal eventType As Integer, ByVal hwnd As IntPtr, ByVal idObject As Integer, ByVal idChild As Integer, ByVal dwEventThread As Integer, ByVal dwmsEventTime As Integer)
Const WINEVENT_OUTOFCONTEXT As Integer = 0
Const EVENT_OBJECT_CREATE As Integer = &H8000
Private hook As IntPtr = IntPtr.Zero
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
hook = SetWinEventHook(EVENT_OBJECT_CREATE, EVENT_OBJECT_CREATE, IntPtr.Zero, AddressOf WinEventProc, 0, 0, WINEVENT_OUTOFCONTEXT)
End Sub
Private Sub Form1_FormClosed(sender As Object, e As FormClosedEventArgs) Handles MyBase.FormClosed
UnhookWinEvent(hook)
End Sub
Private Sub WinEventProc(ByVal hWinEventHook As IntPtr, ByVal eventType As Integer, ByVal hwnd As IntPtr, ByVal idObject As Integer, ByVal idChild As Integer, ByVal dwEventThread As Integer, ByVal dwmsEventTime As Integer)
Dim windowTitle As String = GetWindowText(hwnd)
If windowTitle <> "" AndAlso IsPopupWindow(hwnd) Then
msgbox("New Window Detected")
End If
End Sub
Private Function IsPopupWindow(ByVal hwnd As IntPtr) As Boolean
Dim style As Long = GetWindowLong(hwnd, GWL_STYLE)
Return (style And WS_POPUP) = WS_POPUP
End Function
Declare Auto Function GetWindowLong Lib "user32.dll" (ByVal hWnd As IntPtr, ByVal nIndex As Integer) As Integer
Private Const GWL_STYLE As Integer = -16
Private Const WS_POPUP As Long = &H80000000
Private Function GetWindowText(ByVal hwnd As IntPtr) As String
Dim textLength As Integer = GetWindowTextLength(hwnd) + 1
Dim text As String = New String(" "c, textLength)
GetWindowText(hwnd, text, textLength)
Return text.Trim()
End Function
Declare Auto Function GetWindowText Lib "user32.dll" (ByVal hWnd As IntPtr, ByVal lpString As String, ByVal nMaxCount As Integer) As Integer
Declare Auto Function GetWindowTextLength Lib "user32.dll" (ByVal hWnd As IntPtr) As Integer
What approach could I use to better listen for the creation of new program windows? Or, how could I fix my code?
EVENT_OBJECT_CREATE gets triggered for all kinds of objects, not just windows. You will have to retrieve the created object's window class name via GetClassName() and ignore whichever classes you don't want to process. Menus have a standard class name of #32768.
i write this code to change default printer in windows and work fine but in reload the INI file have a error
this is a code :
Private Sub SetDefaultPrinter(ByVal PrinterName As String, ByVal DriverName As String, ByVal PrinterPort As String)
Dim DeviceLine As String
'rebuild a valid device line string
DeviceLine = PrinterName & "," & DriverName & "," & PrinterPort
'Store the new printer information in the
'[WINDOWS] section of the WIN.INI file for
'the DEVICE= item
Call WriteProfileString("windows", "Device", DeviceLine)
'Cause all applications to reload the INI file
Call SendMessage(HWND_BROADCAST, WM_WININICHANGE, 0, "windows")
End Sub
Private Declare Function WriteProfileString Lib "kernel32" Alias "WriteProfileStringA" (ByVal lpszSection As String, ByVal lpszKeyName As String, ByVal lpszString As String) As Long
Private Declare Function SendMessage Lib "user32" Alias "SendMessageA" (ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, ByVal lparam As String) As Long
Private Const HWND_BROADCAST As Long = &HFFFF&
Private Const WM_WININICHANGE As Long = &H1A
and this is a error :
A call to PInvoke function 'Test!Test.Form2::SendMessage' has unbalanced the stack. This is likely because the managed PInvoke signature does not match the unmanaged target signature. Check that the calling convention and parameters of the PInvoke signature match the target unmanaged signature.
Does anyone have an idea to solve this problem?
Thankful
Private Declare Function SendMessage Lib "user32" Alias "SendMessageA" ( _
ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, _
ByVal lparam As String) As Long
Your data types are wrong. The hwnd parameter is pointer sized, wMsg is a 32 bit value, and wParam, lParam and the return value are pointer sized. Note that Long is a 64 bit type.
Instead it should be
Private Declare Function SendMessage Lib "user32" Alias "SendMessageA" ( _
ByVal hwnd As IntPtr, ByVal wMsg As Integer, ByVal wParam As IntPtr, _
ByVal lparam As String) As IntPtr
Note that I recommend that, in the modern day, you use pinvoke declarations rather than Declare. This offer much more flexibility.
I know how to click a button of another application using the codes below. But now I need to know how to change the selected value of a combo box.
'Declaration
Private Declare Auto Function FindWindow Lib "user32.dll" (ByVal lpClassName As String, ByVal lpWindowName As String) As IntPtr
Private Declare Auto Function FindWindowEx Lib "user32.dll" (ByVal hWndParent As IntPtr, ByVal hWndChildAfter As IntPtr, ByVal lpszClass As String, ByVal lpszWindow As String) As IntPtr
Declare Auto Function PostMessage Lib "user32.dll" (ByVal hWnd As IntPtr, ByVal Msg As Integer, ByVal wParam As IntPtr, ByRef lParam As IntPtr) As IntPtr
Private Const BM_CLICK = &HF5
'Usage
Dim ButtonHandle As IntPtr
Dim MainWindowHandle As IntPtr
MainWindowHandle = FindWindow(FormClass, FormCaption)
ButtonHandle = FindWindowEx(MainWindowHandle, IntPtr.Zero, TargetClass, TargetCaption)
If ButtonHandle <> 0 Then
PostMessage(ButtonHandle, BM_CLICK, 0, 0)
End If
All I need to do is to change the combobox selected value of a different application from its default value of Off to a value of On. Any help is very much appreciated. Thank You.
Finally I now know how to do this. The code that I used is shown below.
'Declaration
Private Declare Auto Function FindWindow Lib "user32.dll" (ByVal lpClassName As String, ByVal lpWindowName As String) As IntPtr
Private Declare Auto Function FindWindowEx Lib "user32.dll" (ByVal hWndParent As IntPtr, ByVal hWndChildAfter As IntPtr, ByVal lpszClass As String, ByVal lpszWindow As String) As IntPtr
Declare Auto Function PostMessage Lib "user32.dll" (ByVal hWnd As IntPtr, ByVal Msg As Integer, ByVal wParam As IntPtr, ByRef lParam As IntPtr) As IntPtr
Private Const BM_CLICK = &HF5
Private Const CB_SETCURSEL = &H14E
'Usage
Dim MainWindowHandle As IntPtr
Dim ChildAfter As IntPtr
Dim ComboBoxHandle As IntPtr
'Get the Handle
MainWindowHandle = FindWindow(FormClass, FormCaption)
'Get the ChildAfter of the Combo Box
ChildAfter = FindWindowEx(MainWindowHandle, IntPtr.Zero, ChildClass, ChildCaption)
'Get the handle of the combobox dropdown
ComboBoxHandle = FindWindowEx(MainWindowHandle, ChildAfter, "ComboBox", vbNullString)
'Select combo box index(1)
PostMessage(ComboBoxHandle, CB_SETCURSEL, 1, 0)
From the MSDN documentation of FindWindowEx:
hwndChildAfter [in, optional]
Type: HWND
A handle to a child window. The search begins with the next child window in the Z order. The child window must be a direct child window of hwndParent, not just a descendant window.
If hwndChildAfter is NULL, the search begins with the first child window of hwndParent.
#RemyLebeau Thank you so much for helping me do this.
i try to make automatic key presser that make minimized game client do order for me while i work in other thing (aion game client) but nothing work here is the code i use please tell me what is wrong with it
Const WM_SETTEXT As Long = &HC
Const GW_CHILD As Long = 5
Declare Function GetWindow Lib "user32.dll" (ByVal hWnd As IntPtr, ByVal uCmd As Integer) As IntPtr
Declare Function FindWindow Lib "user32.dll" Alias "FindWindowA" (ByVal lpClassName As String, ByVal lpWindowName As String) As IntPtr 'Int32
Declare Function SendMessage Lib "user32.dll" Alias "SendMessageA" ( _
ByVal hWnd As IntPtr, _
ByVal wMsg As Int32, _
ByVal wParam As Int32, _
ByVal lParam As String) As Int32
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim hWnd1 As IntPtr = FindWindow("AIONClientWndClass1.0", "AION Client")
Dim hWndR2 As IntPtr = GetWindow(hWnd1, GW_CHILD)
SendMessage(hWndR2, WM_SETTEXT, 0, "h")
End Sub
this is the code i use it must show window in the game when i click button1 , but nothing happen
i use visual studio 2013 and windows 10 64 bit
here is my wrong
1st my app need to run as administrator
2nd have to set target cpu to 86x
3rd i fixed my code , and here it is
Const WM_SETTEXT As Long = &HC
Const GW_CHILD = 5
Const WM_KEYDOWN As Integer = &H100
Const WM_KEYUP As Integer = &H101
Declare Function GetWindow Lib "user32.dll" (ByVal hWnd As IntPtr, ByVal uCmd As Integer) As IntPtr
Declare Function FindWindow Lib "user32.dll" Alias "FindWindowA" (ByVal lpClassName As String, ByVal lpWindowName As String) As IntPtr 'Int32
Declare Function SendMessage Lib "user32.dll" Alias "SendMessageA" (ByVal hWnd As IntPtr,ByVal wMsg As Int32,ByVal wParam As Int32,ByVal lParam As IntPtr) As IntPtr
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim _hndl As IntPtr = FindWindow("AIONClientWndClass1.0", "AION Client")
SendMessage(_hndl, WM_KEYDOWN, &H55, 0)
End Sub
&H55 is virtual key code = u
I want to send "{TAB}" Key to another application window(send the key to the window not to textbox).
I tried:
SendMessage(hWnd, WM_SETHOTKEY, VK_TAB, 0)
Nothing happened.
my goal is:
send tab key to my application Or other application when the application window is not in focus.
(i know that sendkey is not professional in this case there is no choice(This is the first time that I'm using it).)
I made many attempts and I always returned to the same result:
Nothing happened.
Does anyone know the answer?
SendKeys requires the application that you are sending the Keys to, to be active.
From above Link:
Use SendKeys to send keystrokes and keystroke combinations to the active application.
I order to get around this limitation you will have to resort to using the WinApi Functions.
FindWindow pInvoke.net
FindWindowEx pInvoke.net
sendMessage pInvoke.net
See this MSDN Forum Post for an example
Here is a modified example from that Posting:
Public Class Form1
Declare Function FindWindow Lib "user32" Alias "FindWindowA" _
(ByVal lpClassName As String, ByVal lpWindowName As String) As IntPtr
Declare Function FindWindowEx Lib "user32" Alias "FindWindowExA" _
(ByVal hWnd As IntPtr, ByVal hWndChildAfterA As IntPtr, ByVal lpszClass As String, ByVal lpszWindow As String) As IntPtr
Declare Function SendMessage Lib "user32" Alias "SendMessageA" _
(ByVal hWnd As IntPtr, ByVal wMsg As Integer, ByVal wParam As IntPtr, ByVal lParam As String) As IntPtr
Const WM_SETTEXT As Integer = &HC
Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
Dim destination As IntPtr = FindWindow(Nothing, "Untitled - Notepad")
Dim destControl As IntPtr = FindWindowEx(destination, IntPtr.Zero, "Edit", Nothing)
SendMessage(destControl, WM_SETTEXT, IntPtr.Zero, "Hello" & vbTab & "GoodBye" & vbCrLf)
End Sub
End Class
Added an Additional Example using WM_KEYDOWN I created another small application with the Window Title set to TestForm and overrode the WndProc Method to determine if the application got the TabKey.
Sending Form
Public Class Form1
Declare Function FindWindow Lib "user32" Alias "FindWindowA" _
(ByVal lpClassName As String, ByVal lpWindowName As String) As IntPtr
Declare Function SendMessage Lib "user32" Alias "SendMessageA" _
(ByVal hWnd As IntPtr, ByVal wMsg As Integer, ByVal wParam As Integer, ByVal lParam As Integer) As IntPtr
Const WM_KEYDOWN As Integer = &H100
Const VK_TAB As Integer = &H9
Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
Dim destination As IntPtr = FindWindow(Nothing, "TestForm")
SendMessage(destination, WM_KEYDOWN, VK_TAB, 0)
End Sub
End Class
Test Form
Put a breakpoint on MyBase.WndProc(m) and look at m to see what has been sent.
Public Class Form1
Protected Overrides Sub WndProc(ByRef m As System.Windows.Forms.Message)
MyBase.WndProc(m)
End Sub
End Class
Having struggled with this type of this a few times before, i would suggest a couple of things to look at.
The 1st is autoit which includes a dll you can reference from vb.net, and is very simple you use, and well documented. I tend to use that whenever i need to control a 3rd party program.
The other is the ui automation classes
See this for an example:
http://blog.functionalfun.net/2009/06/introduction-to-ui-automation-with.html
you need make the other window active first. check Change focus to another window in VB.NET . then use send key.