Visual Basic

16-Jan-04 6:14

When I need to do this, I open wordpad (not word) and i type in some text, do some formatting and examine the structure of the generated rtf file Smile | :)

greetz

*Niels Penneman*

Converting a bitmap to an array of pixels

elchip14-Jan-04 11:06

elchip

14-Jan-04 11:06

I have a question that may or may not be difficult to answer... I've never done anything like this before.

Could anyone provide me with information about how I could use visual basic 6 (not .net) to convert a bitmap image to a 2D array of pixels? I've found a reference page on the format of a BMP file, but it's not as detailed as I would hope... and when I try to use file input from the BMP file, I just come up with mostly null strings instead of usable bytes.

WM_NOTIFY Reports incorrect values

Knight Lore14-Jan-04 7:46

Knight Lore

14-Jan-04 7:46

Im new to vb.net and Im trying to move mi apliccations to the new language...and i have the following problem.

Im trying to intercept the ListView messages because i want a LV footer to autoresize when a column resize.
I create a Class inherit a LV and override the WndProc sub. But when i try to intercept the WM_NOTIFY message, the asociated code seems incorrect.

Here is my code (the class):

-----------------------------------------------------------------------------
Public Class MyListView
Inherits System.Windows.Forms.ListView

Structure NMHDR
Dim hwndFrom As Long ' Window handle of control sending message
Dim idFrom As Long ' Identifier of control sending message
Dim code As Long ' Specifies the notification code
End Structure

Structure NMHEADER
Dim hdr As NMHDR
Dim iItem As Long
Dim iButton As Long
Dim lPtrHDItem As Long ' HDITEM FAR* pItem
End Structure

Public Const WM_NOTIFY = &H4E
Public Const WM_PAINT = &HF
Public Const WM_USER = &H400
Public Const WM_REFLECT = WM_USER + &H1C00
Const HDN_FIRST As Long = -300&
Const HDN_LAST As Long = -399&
Const HDN_GETDISPINFO As Long = (HDN_FIRST - 9)
Const HDN_BEGINDRAG As Long = (HDN_FIRST - 10)
Const HDN_ENDDRAG As Long = (HDN_FIRST - 11)
Const HDN_ITEMCLICK As Long = (HDN_FIRST - 2)
Const HDN_ITEMDBLCLICK As Long = (HDN_FIRST - 3)
Const HDN_DIVIDERDBLCLICK As Long = (HDN_FIRST - 5)
Const HDN_ITEMCHANGING As Long = (HDN_FIRST - 0)
Const HDN_ITEMCHANGED As Long = (HDN_FIRST - 1)
Const HDN_BEGINTRACK As Long = (HDN_FIRST - 6)
Const HDN_ENDTRACK As Long = (HDN_FIRST - 7)
Const HDN_TRACK As Long = (HDN_FIRST - 8)
Const NM_FIRST As Long = -0& ' (0U- 0U)
Const NM_CUSTOMDRAW As Long = (NM_FIRST - 12)
Const NM_RCLICK As Long = (NM_FIRST - 5)
Const NM_RELEASEDCAPTURE As Long = (NM_FIRST - 16)
Const NM_CLICK As Long = NM_FIRST - 2
Const LVN_FIRST As Long = 100
Const LVN_COLUMNCLICK As Long = LVN_FIRST - 8

Protected Overrides Sub WndProc(ByRef m As Message)
Dim nmh As NMHDR

Select Case m.Msg

Case WM_NOTIFY
nmh = CType(m.GetLParam(nmh.GetType), NMHDR)
If nmh.code = HDN_BEGINTRACK Then
MsgBox("track")
End If

End Select

MyBase.WndProc(m)

End Sub

End Class
'-----------------------------------------------------------------------------

The WM_NOTIFY is detected OK. But I cant get the HDN_BEGINTRACK code. Instead, I get some stranges values
like 5334658619277312 or 5334486820585472

Please HELP!

Thanks in advance.

Niels Penneman14-Jan-04 9:39

14-Jan-04 9:39

First of all, in VB.NET long becomes integer, integer becomes short, ...

This may not solve your problem, but will help you with this and future translations Smile | :)

I suggest you read the translation guidelines @ MSDN

greetz Wink | ;-)

*Niels Penneman*

Knight Lore15-Jan-04 4:07

Knight Lore

15-Jan-04 4:07

Thanks a lot Niels!!

Your sugestion was good, it help me a bit...
Now the values looks more "real"....but aparently
appears increased in 20 (i.e.: -326 instead -306)
But now I'm closer to the solution!
Any idea why this happenns?

Niels Penneman15-Jan-04 6:19

15-Jan-04 6:19

Values are NOT incorrect... look what I found Smile | :)

Hdn_begintrackw: INTEGER is -326
			-- Notifies a header control's parent window that the user has
			-- begun dragging a divider in the control (that is, the user
			-- has pressed the left mouse button while the mouse cursor is
			-- on a divider in the header control). This notification
			-- message is sent in the form of a WM_NOTIFY message.
			--
			-- Declared in Windows as HDN_BEGINTRACK

I found it here Wink | ;-)

greetz

*Niels Penneman*

Niels Penneman15-Jan-04 6:20

15-Jan-04 6:20

Correct translation to VB.NET is here:

Structure NMHDR
    Dim hwndFrom As IntPtr ' Window handle of control sending message
    Dim idFrom As Integer ' Identifier of control sending message
    Dim code As Integer ' Specifies the notification code
End Structure

Structure NMHEADER
    Dim hdr As NMHDR
    Dim iItem As Integer
    Dim iButton As Integer
    Dim lPtrHDItem As IntPtr ' HDITEM FAR* pItem
End Structure

greetz

*Niels Penneman*