[RESOLVED] TextBox.GetLastVisibleLineIndex-Method not available

[TheTree]

Hi all,

I found a TextBox.GetLastVisibleLineIndex-method in the online documentation. But it is not available in my code. I´m using Visual Basic 2008 Express Edition. Is that the reason?

Greetings,

TheTree

[stlaural]

I don't know where you saw that but here's the methods list of the TextBox on msdn and GetLastVisibleLineIndex is not one of them.

[.paul.]

it's listed in object browser

[TheTree]

and it´s listed here: ms-help://MS.VSCC.v90/MS.MSDNQTR.v90.de/fxref_system.windows.controls/html/e90bae0d-ddb7-ee24-67ad-f2228bb17cd7.htm

Greetings,

TheTree

[.paul.]

i found it. it's WPF

[TheTree]

Hi .paul,

thanks for your reply.

What do I have to do, to use WPF-methods. Can I install something to Visual Basic 2008 Express Edition to use it?

Greetings,

TheTree

[stlaural]

Yeah I just noticed that it IS in textbox members list even if its not in its methods list on msdn.

As we can see here its assembly is PresentationFramework.

that explains it, thanks .paul.

[.paul.]

you can do it with the sendmessage API:

Private Declare Function SendMessage Lib "user32" _
            Alias "SendMessageA" (ByVal hwnd As Integer, _
            ByVal wMsg As Integer, ByVal wParam As Integer, _
            ByVal lParam As Integer) As Integer
 
Private Const EM_GETFIRSTVISIBLELINE As Integer = &HCE

Dim height As Integer = CInt(TextBox3.CreateGraphics().MeasureString(TextBox3.Lines(0), TextBox3.Font, TextBox3.Width).Height)
MsgBox(((TextBox3.ClientSize.Height \ height) + SendMessage(TextBox3.Handle.ToInt32, EM_GETFIRSTVISIBLELINE, 0, 0)) - 1)

[TheTree]

Hi .paul.,

Thank you very much. Now its running!

I´m so glad!



Thanks to Alex, too.

Greetings,

TheTree

[.paul.]

here's an extensions module with 2 functions that extend the textbox class:

Module extensions
 
    Private Declare Function SendMessage Lib "user32" _
            Alias "SendMessageA" (ByVal hwnd As Integer, _
            ByVal wMsg As Integer, ByVal wParam As Integer, _
            ByVal lParam As Integer) As Integer
 
    Private Const EM_GETFIRSTVISIBLELINE As Integer = &HCE
 
    <System.Runtime.CompilerServices.Extension()> _
    Public Function GetFirstVisibleLineIndex(ByVal instance As TextBox) As Integer
        Return SendMessage(instance.Handle.ToInt32, EM_GETFIRSTVISIBLELINE, 0, 0)
    End Function
 
    <System.Runtime.CompilerServices.Extension()> _
    Public Function GetLastVisibleLineIndex(ByVal instance As TextBox) As Integer
        Dim height As Integer = CInt(instance.CreateGraphics().MeasureString("0123456789", instance.Font, instance.Width).Height)
        Dim bottomLineIndex As Integer = ((instance.ClientSize.Height \ height) + SendMessage(instance.Handle.ToInt32, EM_GETFIRSTVISIBLELINE, 0, 0)) - 1
        Return If(bottomLineIndex <= instance.Lines.GetUpperBound(0), bottomLineIndex, instance.Lines.GetUpperBound(0))
    End Function
 
End Module

to use the functions, add the module to your project, then:

MsgBox(TextBox1.GetFirstVisibleLineIndex)
MsgBox(TextBox1.GetLastVisibleLineIndex)

[TheTree]

Wow. That´s perfect!

Thank you very much.

TheTree