Получить текст из SysListView32

Question

Я использую приведенный ниже код, чтобы получить текст, содержащийся в SysListView32, но он всегда возвращает пустую строку в retval.

Мне нужно захватить все содержимое всех строк и столбцов.

В чем ошибка?

Я работаю в VB. NET Проект e, и я использую Windows 10 - 64 бита.

Извините за мой плохой английский sh.

Public Shared Function ReadListViewItem(ByVal hWnd As IntPtr, ByVal item As Integer, ByVal subItem As Integer) As String
        Const dwBufferSize As Integer = 1024
        Dim dwProcessID As Integer
        Dim lvItem As LV_ITEM
        Dim retval As String
        Dim bSuccess As Boolean
        Dim hProcess As IntPtr = IntPtr.Zero
        Dim lpRemoteBuffer As IntPtr = IntPtr.Zero
        Dim lpLocalBuffer As IntPtr = IntPtr.Zero
        Dim threadId As IntPtr = IntPtr.Zero
        Dim myIntPtr As IntPtr
        Try
            lvItem = New LV_ITEM
            lpLocalBuffer = Marshal.AllocHGlobal(dwBufferSize)
            ' Get the process id owning the window
            threadId = GetWindowThreadProcessId(hWnd, dwProcessID)
            If (threadId = IntPtr.Zero) OrElse (dwProcessID = 0) Then
                Throw (New ArgumentException("hWnd"))
            End If
            ' Open the process with all access
            hProcess = OpenProcess(PROCESS_ALL_ACCESS, False, dwProcessID)
            If hProcess = IntPtr.Zero Then
                Throw (New ApplicationException("Falha ao acessar o processo."))
            End If
            ' Allocate a buffer in the remote process
            lpRemoteBuffer = VirtualAllocEx(hProcess, IntPtr.Zero, dwBufferSize, MEM_COMMIT, PAGE_READWRITE)
            If lpRemoteBuffer = IntPtr.Zero Then
                Throw (New SystemException("Falha a alocar memória no processo remoto."))
            End If
            ' Fill in the LVITEM struct, this is in your own process
            ' Set the pszText member to somewhere in the remote buffer,
            ' For the example I used the address imediately following the LVITEM stuct
            lvItem.mask = LVIF_TEXT Or LVIF_IMAGE
            lvItem.iItem = item
            myIntPtr = New IntPtr((lpRemoteBuffer.ToInt32() + Marshal.SizeOf(GetType(LV_ITEM))))
            lvItem.pszText = myIntPtr
            lvItem.cchTextMax = 50
            lvItem.iSubItem = subItem
            lvItem.iImage = 1
            'lvItem.cchTextMax = 1 
            ' Copy the local LVITEM to the remote buffer
            bSuccess = WriteProcessMemory(hProcess, lpRemoteBuffer, lvItem, Marshal.SizeOf(GetType(LV_ITEM)), IntPtr.Zero)
            If Not bSuccess Then
                Throw (New SystemException("Falha ao escrever processo na memória."))
            End If
            ' Send the message to the remote window with the address of the remote buffer
            SendMessage(hWnd, LVM_GETITEM, 0, lpRemoteBuffer)
            ' Read the struct back from the remote process into local buffer
            bSuccess = ReadProcessMemory(hProcess, lpRemoteBuffer, lpLocalBuffer, dwBufferSize, IntPtr.Zero)
            If Not bSuccess Then
                Throw (New SystemException("Falha ao ler processo da memória."))
            End If
            ' At this point the lpLocalBuffer contains the returned LV_ITEM structure
            ' the next line extracts the text from the buffer into a managed string
            myIntPtr = New IntPtr((lpLocalBuffer.ToInt32() + Marshal.SizeOf(GetType(LV_ITEM))))
            retval = Marshal.PtrToStringAnsi(myIntPtr)
        Catch ex As ArgumentOutOfRangeException
            Console.Write(ex.Message)
            retval = ""
        Finally
            If lpLocalBuffer <> IntPtr.Zero Then
                Marshal.FreeHGlobal(lpLocalBuffer)
            End If
            If lpRemoteBuffer <> IntPtr.Zero Then
                VirtualFreeEx(hProcess, lpRemoteBuffer, 0, MEM_RELEASE)
            End If
            If hProcess <> IntPtr.Zero Then
                CloseHandle(hProcess)
            End If
        End Try
        Return (retval)
    End Function