I have an app that sits as a trayicon in the system tray. I have registered a Hotkey that when pressed will capture the current text selection in any application, even in Web Browsers.
My aproach is to send the key combination {Ctlr + C} to copy the text. Then access the Clipboard and use the text in my own application.
I am programming in VB.NET but any help in C# or even C++ with Win32_Api would be highly appreciated.
I use AutoHotkey and there, I have a script which access the Clipboard text and works fine.
Pause::
clipboard = ; Start off empty to allow ClipWait to detect when the text has arrived.
Send ^c
ClipWait, 2 ; Wait for the clipboard to contain text.
if ErrorLevel
{
;Do nothing after 2 seconds timeout
return
}
Run https://translate.google.com/#auto/es/%clipboard%
return
As AutoHotkey is open source, I downloaded the code and try to replicate the behaviour of ClipWait as much as I could.
My code works most of the time but sometimes there is an important delay. I cannot access the Clipboard and the win32 function IsClipboardFormatAvailable() keeps returning False for a While. This happens when I am trying to copy from Google Chrome specially in editable TextBoxes.
I tried a lot of different things including using the .Net Framework Clipboard Class. I read the problem could be that the thread that was running the commands was not set as STA, so I did it. In my desperation I also put a timer but nothing solves the problem completely.
I read as well the option of putting a hook to monitor the Clipboard, but I would like to avoid this unless it is the only way of doing it.
Here is my VB.NET code:
Imports System.Runtime.InteropServices
Imports System.Text
Imports System.Threading
Imports Hotkeys
Public Class Form1
Public m_HotKey As Keys = Keys.F6
Private Sub RegisterHotkeys()
Try
Dim alreaydRegistered As Boolean = False
' set the hotkey:
''---------------------------------------------------
' add an event handler for hot key pressed (or could just use Handles)
AddHandler CRegisterHotKey.HotKeyPressed, AddressOf hotKey_Pressed
Dim hkGetText As HotKey = New HotKey("hkGetText",
HotKey.GetKeySinModificadores(m_HotKey),
HotKey.FormatModificadores(m_HotKey.ToString),
"hkGetText")
Try
CRegisterHotKey.HotKeys.Add(hkGetText)
Catch ex As HotKeyAddException
alreaydRegistered = True
End Try
Catch ex As Exception
CLogFile.addError(ex)
End Try
End Sub
Private Sub hotKey_Pressed(sender As Object, e As HotKeyPressedEventArgs)
Try
Timer1.Start()
Catch ex As Exception
CLogFile.addError(ex)
End Try
End Sub
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
RegisterHotkeys()
End Sub
Function copyText() As String
Dim result As String = String.Empty
Clipboard.Clear()
Console.WriteLine("Control + C")
SendKeys.SendWait("^c")
Dim Attempts As Integer = 100
Do While Attempts > 0
Try
result = GetText()
If result = String.Empty Then
Attempts -= 1
'Console.WriteLine("Attempts {0}", Attempts)
Thread.Sleep(100)
Else
Attempts = 0
End If
Catch ex As Exception
Attempts -= 1
Console.WriteLine("Attempts Exception {0}", Attempts)
Console.WriteLine(ex.ToString)
Threading.Thread.Sleep(100)
End Try
Loop
Return result
End Function
#Region "Win32"
<DllImport("User32.dll", SetLastError:=True)>
Private Shared Function IsClipboardFormatAvailable(format As UInteger) As <MarshalAs(UnmanagedType.Bool)> Boolean
End Function
<DllImport("User32.dll", SetLastError:=True)>
Private Shared Function GetClipboardData(uFormat As UInteger) As IntPtr
End Function
<DllImport("User32.dll", SetLastError:=True)>
Private Shared Function OpenClipboard(hWndNewOwner As IntPtr) As <MarshalAs(UnmanagedType.Bool)> Boolean
End Function
<DllImport("User32.dll", SetLastError:=True)>
Private Shared Function CloseClipboard() As <MarshalAs(UnmanagedType.Bool)> Boolean
End Function
<DllImport("Kernel32.dll", SetLastError:=True)>
Private Shared Function GlobalLock(hMem As IntPtr) As IntPtr
End Function
<DllImport("Kernel32.dll", SetLastError:=True)>
Private Shared Function GlobalUnlock(hMem As IntPtr) As <MarshalAs(UnmanagedType.Bool)> Boolean
End Function
<DllImport("Kernel32.dll", SetLastError:=True)>
Private Shared Function GlobalSize(hMem As IntPtr) As Integer
End Function
Private Const CF_UNICODETEXT As UInteger = 13UI
Private Const CF_TEXT As UInteger = 1UI
#End Region
Public Shared Function GetText() As String
If Not IsClipboardFormatAvailable(CF_UNICODETEXT) AndAlso Not IsClipboardFormatAvailable(CF_TEXT) Then
Return Nothing
End If
Try
If Not OpenClipboard(IntPtr.Zero) Then
Return Nothing
End If
Dim handle As IntPtr = GetClipboardData(CF_UNICODETEXT)
If handle = IntPtr.Zero Then
Return Nothing
End If
Dim pointer As IntPtr = IntPtr.Zero
Try
pointer = GlobalLock(handle)
If pointer = IntPtr.Zero Then
Return Nothing
End If
Dim size As Integer = GlobalSize(handle)
Dim buff As Byte() = New Byte(size - 1) {}
Marshal.Copy(pointer, buff, 0, size)
Return Encoding.Unicode.GetString(buff).TrimEnd(ControlChars.NullChar)
Finally
If pointer <> IntPtr.Zero Then
GlobalUnlock(handle)
End If
End Try
Finally
CloseClipboard()
End Try
End Function
Private Sub Timer1_Tick(sender As Object, e As EventArgs) Handles Timer1.Tick
Try
Timer1.Stop()
Dim ThreadA As Thread
ThreadA = New Thread(AddressOf Me.copyTextThread)
ThreadA.SetApartmentState(ApartmentState.STA)
ThreadA.Start()
Catch ex As Exception
CLogFile.addError(ex)
End Try
End Sub
Sub copyTextThread()
Dim result As String = copyText()
If result <> String.Empty Then
MsgBox(result)
End If
End Sub
End Class
I also searched in other similar questions without a final solution to my problem:
Send Ctrl+C to previous active window
How do I get the selected text from the focused window using native Win32 API?
