Windows Forms

Problem with sizing an image to fit drawn text

1-Jul-09 22:51

The user control should raise events that the Form (or some form manager class) can subscribe to - much the same as when you put, say, a button on a form. The button doesn't know about the form, but the form responds to the buttons' events but only the ones that it has requested to be informed about.

Dave
BTW, in software, hope and pray is not a viable strategy. (Luc Pattyn)
Visual Basic is not used by normal people so we're not covering it here. (Uncyclopedia)
Why are you using VB6? Do you hate yourself? (Christian Graus)

Alan Burkhart30-Jun-09 19:21

Alan Burkhart

30-Jun-09 19:21

Using VB.net...

I'm trying to size an in-memory bitmap to fit the text from a textbox. My steps are:
1. Get the height of the font (Font.Height) in the textbox.
2. Get the number of lines in the textbox.
3. Multiply the font height by the line count
4. Size the bitmap to textbox.width and font.height multiplied by the line count for the height
5. Create a rectangle sized to the bitmap
6. Draw the text in the bitmap within the rectangle
7. Set a picturebox's image property to the bitmap (picturebox sizemode set to autosize)

This works fine IF the textbox doesn't have a scrollbar. If it's a long text file, the image is only about half as tall as it needs to be.

Here's my code (RichTextBox named "rtf"):

  Private Sub tb_Draw_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles tb_Draw.Click

Dim fh As Integer 'font height
Dim cw As Integer 'rtf.width
Dim ch As Integer 'rtf.text height
Dim lineCount As Integer 'rtf.lines.length
Dim bmp As Bitmap
Dim g As Graphics

  fh = rtf.Font.Height
  cw = rtf.Width
  lineCount = rtf.Lines.Length
  ch = lineCount * fh
  rect = New Rectangle(0, 0, cw, ch)
  bmp = New Bitmap(cw, ch, Imaging.PixelFormat.Format32bppArgb)

  g = Graphics.FromImage(bmp)
  g.FillRectangle(Brushes.White, rect)
  g.DrawString(rtf.Text, rtf.Font, Brushes.Black, rect)

  picbox.Image = bmp

End Sub

The textbox only uses a single font.

What am I doing wrong?

getModuleFileNameEx

johnl012930-Jun-09 5:38

30-Jun-09 5:38

I am having trouble with the getModuleFileNameEx api call in a VB.net application. It will not return to me the filepath of the currently active window. Any idea what i am doing wrong?

nextWnd = GetForegroundWindow()

' Gets title and path of the active window
GetWindowText(nextWnd, lpString, lpString.Capacity)
GetWindowThreadProcessId(nextWnd, procID)
modTest = GetModuleFileNameEx(procID, nullWnd, lpFileName, 500)

Thanks,
John

DaveyM6930-Jun-09 6:14

30-Jun-09 6:14

I'm not sure - I don't do VB. The following works in C# though to get the path of the executing assembly's process

StringBuilder builder = new StringBuilder(500);
uint modTest = GetModuleFileNameEx(Process.GetCurrentProcess().Handle, IntPtr.Zero, builder, 500);
Console.Write(builder.ToString());

[DllImport("psapi.dll")]
static extern uint GetModuleFileNameEx(IntPtr hProcess, IntPtr hModule, [Out] StringBuilder lpFilename, int nSize);

johnl012930-Jun-09 8:11

30-Jun-09 8:11

Ok,
After trying the code that you gave me (in a VB.net form), I get the same problem I always get:

When i output the stringbuilder object that should be holding the file path, I get 'Ÿ' followed by the title of the window. And it'll only show up for the first click of the button. So stumped.

Thank you for the help though,
~John

Luc Pattyn30-Jun-09 8:28

Luc Pattyn

30-Jun-09 8:28

Hi,

just a hunch: maybe this call won't work as long as the window hasn't been fully initialized (e.g. when the Handle isn't available yet), so don't do this from the Forms' constructor, wait till the Load event.

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

DISCLAIMER: this message may have been modified by others; it may no longer reflect what I intended, and may contain bad advice; use at your own risk and with extreme care.

johnl012930-Jun-09 8:40

30-Jun-09 8:40

The window is fully loaded by the time I execute this code. I have it tied to a timer that'll execute the code once every couple seconds after I hit the timer's start button.

DaveyM6930-Jun-09 10:22

30-Jun-09 10:22

I don't know why it doesn't work for you. I haven't used VB for a long time but I opened up a ne VB WinForms project and did this and it works fine - the Form's Text displays the path.

Imports System.Runtime.InteropServices
Imports System.Text

Public Class Form1
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Me.Load
        Text = GetPathOfThisProcessExe()
    End Sub
    Private Function GetPathOfThisProcessExe() As String
        Dim builder As New StringBuilder(500)
        GetModuleFileNameEx(Process.GetCurrentProcess().Handle, IntPtr.Zero, builder, 500)
        Return builder.ToString()
    End Function
    <DllImport("psapi.dll")> _
    Private Shared Function GetModuleFileNameEx( _
    ByVal hProcess As IntPtr, _
    ByVal hModule As IntPtr, _
    <Out()> ByVal lpFilename As StringBuilder, _
    ByVal nSize As Integer) As UInteger
    End Function
End Class

[Edit] Fixed code formating [/Edit]

johnl012930-Jun-09 11:04

30-Jun-09 11:04

Sigh, this is what i HATE and LOVE about programming lol

The thing that made the entire thing work was add .handle to Process.GetCurrentProcess()

Thank you very much for your help as i had been stuck on this for some time now!
Also... what version of VB were you using out of curiosity?

Thanks,
~John

DaveyM6930-Jun-09 11:17

30-Jun-09 11:17

VB9 (Visual Studio 2008). I used to program exclusively in VB in it's various forms (including VB6 and before!) until about 2 years ago when I decided to switch to / learn C#. I found it comfortable really quickly so I've never had the desire to fire up VB since.

It was very wierd going back. I even had to google to work out how to make a sub handle an event! OMG | :OMG:

Glad it helped - dusted off a few cobwebs for me Big Grin | :-D

DaveyM6930-Jun-09 10:29