How can I automate Winforms of .NET in VB6? | Newbie | | Join Date: Mar 2009
Posts: 2
| |
I want to get the ControlName of .NET properties in VB6 code, just like described in this article. But unfortunately, it doesn't work for me. I always got 0 for bufferMem. - bufferMem = VirtualAllocEx(processHandle, 0, size,
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MEM_RESERVE Or MEM_COMMIT, PAGE_READWRITE)
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If bufferMem = 0 Then
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Error Err, "VirtualAllocEx API Failed"
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End If
What am I doing wrong?
| | Newbie | | Join Date: Mar 2009
Posts: 2
| | | re: How can I automate Winforms of .NET in VB6?
Hi All,
I have managed VirtualAllocEx. Before I declared this function as Private. Then when I moved it to Module file and changed it to Public, I don't get 0 anymore for bufferMem. Also I need to set lpAddress as ByVal. Otherwise, the length of controlName that given is twice than correct length (I don't know exactly how this happens). - Declare Function VirtualAllocEx Lib "kernel32" _
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(ByVal hProcess As Long, _
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ByVal lpAddress As Long, _
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ByVal dwSize As Long, _
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ByVal flAllocationType As Long, _
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ByVal flProtect As Long) As Long
Now I got the correct retLength, but unfortunately retVal is 0, return the error description: Invalid procedure call or argument. - If retLength <> 0 Then
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'Now read the component's name from the shared memory location.
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retVal = ReadProcessMemory(processHandle, bufferMem, bytearray, size, VarPtr(written))
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If retVal = 0 Then
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Error Err 'ReadProcessMemory API Failed
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End If
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End If
My declaration of ReadProcessMemory is: - Declare Function ReadProcessMemory Lib "kernel32" _
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(ByVal hProcess As Long, _
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ByVal lpBaseAddress As Long, _
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lpBuffer As Any, _
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ByVal nSize As Long, _
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lpNumberOfBytesRead As Long) As Long
And when I run the whole thing (ignore the retVal value), I got error in WideCharToMultiByte: - Function ByteArrayToString(bytes As String, length As Long) As String
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Dim retValStr As String
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Dim l As Long
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If IsWin9x() Then
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retValStr = Left(bytes, InStr(1, bytes, Chr(0)) - 1)
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Else
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retValStr = String$(length + 1, Chr(0))
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l = WideCharToMultiByte(CP_ACP, 0, bytes, -1, retValStr, length + 1, Null, Null)
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End If
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ByteArrayToString = retValStr
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End Function
The error is saying: - Run-time error '94':
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Invalid use of Null
Any idea?
Here is the code: - Function GetWindowsFormsID(ByVal wnd As Long) As String
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Dim PID As Long 'pid of the process that contains the control
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Dim msg As Long
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' Define the buffer that will eventually contain the desired
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' component's name.
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Dim bytearray As String * 65526
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' Allocate space in the target process for the buffer as shared
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' memory.
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Dim bufferMem As Long
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' Base address of the allocated region for the buffer.
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Dim size As Long
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' The amount of memory to be allocated.
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Dim written As Long
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' Number of bytes written to memory.
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Dim retLength As Long
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Dim retVal As Long
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Dim errNum As Integer
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Dim errDescription As String
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size = 65527 'Len(bytearray)
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' Creating and reading from a shared memory region is done
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' differently in Win9x than in newer Oss.
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Dim processHandle As Long
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Dim fileHandle As Long
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msg = RegisterWindowMessage("WM_GETCONTROLNAME")
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If Not IsWin9x() Then
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On Local Error GoTo Error_Handler_NT
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Dim dwResult As Long
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Call GetWindowThreadProcessId(wnd, PID)
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processHandle = OpenProcess(PROCESS_VM_OPERATION Or PROCESS_VM_READ Or PROCESS_VM_WRITE, 0, PID)
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If processHandle = 0 Then
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Error Err 'OpenProcess API Failed
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End If
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bufferMem = VirtualAllocEx(processHandle, 0, size, MEM_RESERVE Or MEM_COMMIT, PAGE_READWRITE)
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If bufferMem = 0 Then
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Error Err 'VirtualAllocEx API Failed
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End If
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' Send message to the control's HWND for getting the
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' Specified control name.
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retLength = SendMessage(wnd, msg, size, ByVal bufferMem)
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If retLength <> 0 Then
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' Now read the component's name from the shared memory location.
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retVal = ReadProcessMemory(processHandle, bufferMem, bytearray, size, VarPtr(written))
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If retVal = 0 Then
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Error Err 'ReadProcessMemory API Failed
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End If
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End If
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Error_Handler_NT:
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errNum = Err
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errDescription = Error$
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' Free the memory that was allocated.
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retVal = VirtualFreeEx(processHandle, bufferMem, 0, MEM_RELEASE)
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If retVal = 0 Then
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Error Err 'VirtualFreeEx API Failed
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End If
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CloseHandle (processHandle)
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If errNum <> 0 Then
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On Local Error GoTo 0
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Error errNum 'errDescription
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End If
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On Local Error GoTo 0
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-
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Else
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On Local Error GoTo Error_Handler_9x
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Dim SA As SECURITY_ATTRIBUTES
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fileHandle = CreateFileMapping(INVALID_HANDLE_VALUE, SA, PAGE_READWRITE, 0, size, Null)
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If fileHandle = 0 Then
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Error Err 'CreateFileMapping API Failed
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End If
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bufferMem = MapViewOfFile(fileHandle, FILE_MAP_ALL_ACCESS, 0, 0, 0)
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If bufferMem = 0 Then
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Error Err 'MapViewOfFile API Failed
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End If
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Call CopyMemory(bufferMem, bytearray, size)
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' Send message to the treeview control's HWND for
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' getting the specified control's name.
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retLength = SendMessage(wnd, msg, size, bufferMem)
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' Read the control's name from the specific shared memory
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' for the buffer.
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Call CopyMemoryA(bytearray, bufferMem, 1024)
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Error_Handler_9x:
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errNum = Err
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errDescription = Error$
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' Unmap and close the file.
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UnmapViewOfFile (bufferMem)
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CloseHandle (fileHandle)
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If errNum <> 0 Then
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On Local Error GoTo 0
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Error errNum 'errDescription
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End If
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On Local Error GoTo 0
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End If
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If retLength <> 0 Then
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' Get the string value for the Control name.
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GetWindowsFormsID = ByteArrayToString(bytearray, retLength)
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End If
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End Function
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