[vb .net] Go to Line in textbox/richtextbox

[bangbang023 Veteran]

Can anyone tell me the general idea of how to implement a "go to line number" in a textbox in vb .net? I know how to get the current line number, but I really can't figure out how to put the cursor at the beginning of a line number entered into a dialog. I found one example online, but it relied on the assumption that word wrap would be off which doesn't work in my case.

Any help would be appreciated.

[bangbang023 Veteran]

anyone?

[Ianmac45]

Public Sub [GoTo](ByVal ln As Integer)
  Win32.LockWindowUpdate(rtb.Handle)
  SelectionStart = Win32.SendMessage(rtb.Handle, Win32.EM.LINEINDEX, ln - 1, 0)
  Win32.LockWindowUpdate(IntPtr.Zero)

rtb.Focus()
End Sub

the lockwindowupdate calls aren't necessary, but they do help prevent flicker

Edited July 16, 2005 by Ianmac45

[bangbang023 Veteran]

im getting an error that lockwindowupdarte and sendmessage aren't members of win32

[bangbang023 Veteran]

elliot: your code assumes the line being searched for is below the current caret position.

[elliot]

I don't understand that either. I did it like this

Public Class TextBox2
    Inherits TextBox

    Public Property LineNumber()
        Get
            'i dunno
            Return 0
        End Get
        Set(ByVal value)
            Me.SelectionStart = 0

            For i As Integer = 1 To value
                SendKeys.Send("{DOWN           Next i
        End Set
    End Property

End Class

[bangbang023 Veteran]

  elliot said:

Me.SelectionStart = 0

I reset it the position to the top left. :)

586224601[/snapback]

Hmm, I guess that would work. I'm just worried about the execution time on a large file. The other day I was working on files from Firefox that are 10,000+ lines long and realized that finding line 5904 can be difficult. With your code, it could take a while to get to the line.

[elliot]

Me.SelectionStart = 0

I reset it the position to the top left. :)

[elliot]

Hmm yeah I just tested it and it was about 5 seconds to do 1000 lines.

Hopefully Ianmac45's is better if you can get it working.

[Ianmac45]

mine does work

just include the lockwindowupdate and sendmessage api calls

i thought you guys would be able to figure it out, i guess not

Public Declare Auto Function LockWindowUpdate Lib "user32" (ByVal handle As IntPtr) As Boolean

Public Declare Auto Function SendMessage Lib "user32" Alias "SendMessageA" (ByVal handle As IntPtr, ByVal wMsg As Integer, ByVal wParam As Integer, ByVal lParam As Integer) As Integer

[Ianmac45]

just to tell you all,

Const EM_LINEINDEX = &HBB

[smurfiness]

You can use the Win32 SendMessage function to send an EM_LINESCROLL message to the RichText/TextBox control.

http://msdn.microsoft.com/library/default...._linescroll.asp

[Ianmac45]

mine does work, seriously, just try it

[+virtorio MVC]

Ianmac45's will work fine, you just need to import the SendMessage and LockWindowUpdate (actually I've never used LockWindowUpdate before so I assume it's right) functions manually as Ianmac45 didn't include the Win32 unit.

[bangbang023 Veteran]

Thanks. Honestly, I've never worked with user32 before so I wasn't fully aware of the method. Anyways, your code did work with a little editing. Thank you.