Question

I am hoping that someone can help me with a problem I’ve got at the moment using Compact Framework.Net 2 SP 2.

At the moment I have a UI with a series of text boxes and each textbox displays the contents of a database field. These are shown one beneath another with a scroll bar on the right hand side of the form. Each textbox has a set width which might

I would like to adjust the height each text box based on the number of lines it is holding, the font size and the font in order to avoid using scroll bars on each textbox.

At the moment I am been able to do this in a test application.

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Screenshot:

see screenshot for output http://morrislgn.brinkster.net/SO/screenshot.jpg

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My code:

'Text used in this example:
'TextBox1qwertyuiop lkjhgfdsazxcvbnm1234567890 TextBo

'x1qwer tyuioplkjhgfdsazxcvb nm1234567890

'qwe
'End of exmaple text.
            
Me.Textbox2.Text = Me.Textbox1.Text

Dim pobjGraphic As Graphics = Me.Textbox2.Parent.CreateGraphics()
Dim pobjSize As SizeF
            
'Padding values:
Dim piTop As Int32 = 4 'top of text and top of textbox
Dim piBottom As Int32 = 3 'bottom of text and top of textbox
            
Dim piLines As Int32 = 0

'Based on the font size chosen by the user, create a font to perform the calculation with.
Dim piFontSize As Single = 10

If Me.CheckBox1.Checked.Equals(True) Then
    piFontSize = 6
ElseIf Me.CheckBox2.Checked.Equals(True) Then
    piFontSize = 8
ElseIf Me.CheckBox3.Checked.Equals(True) Then
    piFontSize = 12
Else
    piFontSize = 10
End If

Dim pobjFont As New Font("Tahoma", piFontSize, FontStyle.Regular)

'Calculate the height of one line.
pobjSize = pobjGraphic.MeasureString("HELLO WORLD", pobjFont)
'Value of pobjSize returned: {Width = 71.0 Height = 13.0}
            
            
'Calculate the number of lines          
Dim b As Bitmap
b = New Bitmap(1, 1, Imaging.PixelFormat.Format32bppRgb)
            
'Calculate the number of lines required to display the text properly based on the lenght of the text the width of the control.
'Length of text to show divide by the width of the textbox
piLines = Graphics.FromImage(b).MeasureString(Me.Textbox2.Text, pobjFont).Width / Me.Textbox2.Width
'Value of piLines returned: 2

If piLines = 0 Then
    piLines = 1
End If
            
'Calculate the size of the text to be displayed using the margins, height of one line and number of lines.
Me.Textbox2.Height = (pobjSize.Height * piLines) + piTop + piBottom
' value produced: 33 = (13 * 2) + 4 + 3
'set font of text box
Me.Textbox2.Font = pobjFont

Finally, I know this can be achieved using a call to the COREDLL.dll using p/invoke but doing this makes the application crash.

Hi Folks,

Below is the pinvoke code as requested:

    <Runtime.InteropServices.DllImport("coredll.dll")> _
Private Function SendMessage( _
    ByVal hwnd As IntPtr, ByVal msg As Integer, _
    ByVal wParam As Integer, ByVal lParam As Integer) As Integer
End Function

<Runtime.InteropServices.DllImport("coredll.dll")> _
Private Function GetCapture() As IntPtr
End Function

<Runtime.InteropServices.DllImport("coredll.dll")> _
Private Function ReleaseCapture() As Boolean
End Function

Public Function GetNumberOfLines(ByVal ptxtCountBox As TextBox) As Integer
    Try
        Dim hnd As IntPtr = New IntPtr

        ptxtCountBox.Capture = True

        ' Capture the textbox handle.
        hnd = GetCapture()
        ptxtCountBox.Capture = False

        ' Get the count of the lines in the box.
        Dim plCount As Integer = SendMessage(ptxtCountBox.Handle, EM_GETLINECOUNT, 0, 0)

        ' Count the number of return lines as we minus this from the total lines to take.
        plCount = plCount - (CharCount(ptxtCountBox.Text, vbCrLf, False))

        plCount += RemoveNonASCIIReturns(ptxtCountBox)

        ReleaseCapture()

        hnd = Nothing

        ' Return the line count.
        Return plCount
    Catch ex As Exception
        GenerateError(msCLASS_NAME, "GetNumberOfLines", ex.Message.ToString)
    End Try
End Function

Thanks,

Morris

Answer 1

I asked a similar question and got an answer that completely satisfied my needs on the subject! Please check out stevo3000’s answer from my question:
AutoSize for Label / TextBox in .NET Compact Framework

He referred to these two blog posts that just completely fixed my problem with one swipe!
http://www.mobilepractices.com/2007/12/multi-line-graphicsmeasurestring.html
http://www.mobilepractices.com/2008/01/making-multiline-measurestring-work.html