Visual Basic

Private Const WH_KEYBOARD_LL As Integer = 13
    Private Const WM_KEYUP As Integer = &H101
    Private Const WM_SYSKEYUP As Integer = &H105
    Private proc As LowLevelKeyboardProcDelegate = AddressOf HookCallback
    Private hookID As IntPtr

    Private Delegate Function LowLevelKeyboardProcDelegate(ByVal nCode As Integer, ByVal wParam As IntPtr, _
        ByVal lParam As IntPtr) As IntPtr

    <DllImport("user32")> _
    Private Shared Function SetWindowsHookEx(ByVal idHook As Integer, ByVal lpfn As LowLevelKeyboardProcDelegate, _
        ByVal hMod As IntPtr, ByVal dwThreadId As UInteger) As IntPtr
    End Function

    <DllImport("user32.dll")> _
    Private Shared Function UnhookWindowsHookEx(ByVal hhk As IntPtr) As <MarshalAs(UnmanagedType.Bool)> Boolean
    End Function

    <DllImport("user32.dll")> _
    Private Shared Function CallNextHookEx(ByVal hhk As IntPtr, ByVal nCode As Integer, ByVal wParam As IntPtr, _
        ByVal lParam As IntPtr) As IntPtr
    End Function

    <DllImport("kernel32.dll", CharSet:=CharSet.Unicode)> _
    Private Shared Function GetModuleHandle(ByVal lpModuleName As String) As IntPtr
    End Function

    Sub New()
        ' This call is required by the Windows Form Designer.
        InitializeComponent()
        ' Add any initialization after the InitializeComponent() call.
        hookID = SetHook(proc)
    End Sub

    Private Sub Form1_FormClosing(ByVal sender As Object, ByVal e As FormClosingEventArgs) Handles Me.FormClosing
        UnhookWindowsHookEx(hookID)
    End Sub

    Private Function SetHook(ByVal proc As LowLevelKeyboardProcDelegate) As IntPtr
        Using curProcess As Process = Process.GetCurrentProcess()
            Using curModule As ProcessModule = curProcess.MainModule
                Return SetWindowsHookEx(WH_KEYBOARD_LL, proc, GetModuleHandle(curModule.ModuleName), 0)
            End Using
        End Using
    End Function

Private Function HookCallback(ByVal nCode As Integer, ByVal wParam As IntPtr, ByVal lParam As IntPtr) As IntPtr
       
        If nCode Then
            Dim vkCode As Integer = Marshal.ReadInt32(lParam)
            If vkCode = Keys.A Then
                SendKeys.Send("B")
                Return CType(1, IntPtr)
            End If
        End If
         Return CallNextHookEx(hookID, nCode, wParam, lParam)
    End Function

Pasan148 wrote:

Is there a way to avoid typing alphabetic keys (A-Z) in any window and track the key which was pressed at same time.

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Cool Smith wrote:

i need to examine a text file containing Arabic writings

Cool Smith wrote:

Do i need to detect the file code-page before reading?

Cool Smith wrote:

by counting each character frequency of each character, how do i do this in vb.net?

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What format is it in? Ideally, it'd be UTF. It's important since the encoding determines the length of a single character. Download a HEX-editor and open the textfile with it - what do the first bytes look like in HEX?

First, determine the encoding, and read the file with that encoding. Then create a dictionary, read the entire file as a string. Loop through the string by eating characters, adding them to the dictionary as the key, or adding +1 to it's value if it's already in the dictionary. When done eating, burp out the results

Cool Smith wrote:

i found code here that can detect the code page of a file

Cool Smith wrote:

can you give me pseudo code for this

// A dictionary, used to count the frequencies
Dictionary<String, Int64> characterCounter = new Dictionary<String, Int64>();

// we'll read the entire file into a string;
string theFile = File.ReadAllText("C:\test.txt");

// we'll keep removing characters and process them, until the string is empty
while (theFile.Length > 0)
{
  // get the char at the end of the string
  string CurrentCharacter = theFile[theFile.Length -1];  

  // remove that thing from the string that holds the file
  string theFile = theFile.Remove(theFile.Length -1, 1); 

  // if the dictionary contains our character
  if (characterCounter.ContainsKey(CurrentCharacter))
  {
    // increase the value of the int
    characterCounter[CurrentCharacter] = characterCounter[CurrentCharacter] + 1;
  }
  else
  {
    // it wasn't in the dictionary yet, so it must be the 
    // first time that we encounter this character. Add it;
    characterCounter.Add(CurrentCharacter, 1);
  }
}

// done with counting, now show the results to the user
for each (DictionaryEntry<String, Int64> entry in characterCounter)
{
  textBox1.Text += String.Format("char {0} occurs {1} times", entry.Key, entry.Value);
}

string theFile = File.ReadAllText("C:\test.txt");

// this will point to the index of the character that we're processing
Int64 currentPos = 0; 
Int64 endPos = theFile.Length -1;

// while the current position in the string doesn't match the end position;
while (currentPos <> endPos)
{
    // fetch the current character from the string, at the current index
    string CurrentCharacter = theFile[currentPos];

    // increase the index
    currentPos = currentPos + 1;

    // rest of dictionary-code here;
    ...
}

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<br />
Private Function ConvertStringToHex(ByVal MyString As String) As String<br />
        Dim Result As String = vbNullString<br />
        If Len(MyString) = 0 Then<br />
            Result = vbNullString<br />
        Else<br />
            For i As Integer = 0 To Len(MyString.Trim) - 1<br />
                Dim MyChar As String = Mid(MyString.Trim, i + 1, 1)<br />
                Result = Result + Xformat(Hex(Microsoft.VisualBasic.AscW(MyChar)))<br />
            Next<br />
        End If<br />
        Return Result<br />
    End Function<br />
    Private Function ConvertHexToString(ByVal MyString As String) As String<br />
<br />
        Dim Result As String = vbNullString<br />
        If Len(MyString) = 0 Then<br />
            Result = vbNullString<br />
        Else<br />
            For i As Integer = 0 To Len(MyString.Trim) - 1 Step 4<br />
                Dim MyChar As String = Mid(MyString.Trim, i + 1, 4)<br />
                Result = Result + Microsoft.VisualBasic.ChrW(Convert.ToInt32(MyChar, 16))<br />
            Next<br />
        End If<br />
        Return Result<br />
<br />
<br />
    End Function<br />
    Function Xformat(ByVal xin As String) As String<br />
        Dim retval As String = xin<br />
        Select Case Len(xin)<br />
            Case Is = 3<br />
                retval = "0" & xin<br />
            Case Is = 2<br />
                retval = "00" & xin<br />
            Case Is = 1<br />
                retval = "000" & xin<br />
        End Select<br />
        Return retval<br />
    End Function<br />
End Class<br />
<br />

Cool Smith wrote:

first am using vb.net not c#, i tried convertin to vb.net

Cool Smith wrote:

Can you provide vb.net version?

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