Visual Basic

Re: opening a form from a string name

22-Feb-05 3:58

My first question would be, why are you passing a form name? Where is this comming from and why can't this code just create the form object itself?

RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome

Shawn200022-Feb-05 4:36

Shawn2000

22-Feb-05 4:36

the formName is coming from a Database which is creating a menu dynamically. Depending on which menu item that is selected depends on which form is opened up.
I could do a select case for each of the forms but I wanted to keep it as dynamic as possible. (I know that if another menu item is added to the database then a new form will need to be manually created that corrosponds to it anyway. But when there are many people working around the same area, then doing it this way saves going back to the same code to popup a new form)

Thanks
Shawn

Re: opening a form from a string name

Dave Kreskowiak22-Feb-05 6:09

Printing + Encoding Magstripe

22-Feb-05 6:09

Well, sounds a bit shakey to me, but... I think you could get away with using Activator.CreateInstance(assemblyName, typeName) to get what you want.

RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome

YorkTech22-Feb-05 0:02

YorkTech

22-Feb-05 0:02

Hi folks

I'm having a bit of trouble with printing. I have an application which creates and prints plastic cards (id cards etc).
I'm trying to encode a magstripe (with a datacard sp55 card printer) but not much sucess.

Now to encode a magstripe you send the printer the tilda char ~ followed by a track and then the data i.e ~1Helloworld

If I print the following from notepad or word:-

~1Track1
~2123456
~37890

All is well and the printer spits out a shiny encoded card. However my vb.net code just prints out the text on the card front!

Code is:-

Private Sub EncodeMagStripe(ByVal e As System.Drawing.Printing.PrintPageEventArgs)

Dim magFont As New Font("Lucida Console", 10)
Dim magBrush As New SolidBrush(Drawing.Color.Black)
Dim lineHeight As Single = magFont.GetHeight(e.Graphics)
Dim yPos As Single = e.MarginBounds.Top
Dim xPos As Single = e.MarginBounds.Left
Dim magTrack1 As String
Dim magTrack2 As String
Dim magTrack3 As String
'If we have Magstripe data send it with the correct escape sequences
'i.e
'~1Testing
'~21234567890
'~31234567890
magTrack1 = "~1" & m_Card.MagTrack1
magTrack2 = "~2" & m_Card.MagTrack2
magTrack3 = "~3" & m_Card.MagTrack3
If IsNothing(m_Card.MagTrack1) = False Then e.Graphics.DrawString(magTrack1, magFont, magBrush, xPos, yPos)
yPos += lineHeight
If IsNothing(m_Card.MagTrack2) = False Then e.Graphics.DrawString(magTrack2, magFont, magBrush, xPos, yPos)
yPos += lineHeight
If IsNothing(m_Card.MagTrack3) = False Then e.Graphics.DrawString(magTrack3, magFont, magBrush, xPos, yPos)
End Sub

Any ideas?

Thanks
Steve.

Dave Kreskowiak22-Feb-05 0:48

22-Feb-05 0:48

Unfortunately, your not printing the string, but printing the image of a string of characters. You have to send the strings to the printer in a Raw format. Something Graphics.DrawString will not do.

This has been covered on the board many, many times. HOW TO: Send Raw Data to a Printer by Using Visual Basic .NET[^]

RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome

YorkTech22-Feb-05 7:11

YorkTech

22-Feb-05 7:11

Yes I thought that may be the case Frown | :-(

I'd seen the RAW article before on MSDN.
Unfortunately just sending the text via RAW isn't practical (as far as I can see) as I also have to print full colour bitmaps and fancy fonts.

I have the datacard SDK which I'll have to play with, it's not .NET complient tho, examples are in VB6 and use the VB6 printer object interpersed with DLL calls. Which the .NET docs say you can't do with the .NET print classes.

The only other way I can see is to automate Word or try the Crystal Reports.

Cheers
Steve.

Dave Kreskowiak22-Feb-05 7:32

22-Feb-05 7:32

Go with the SDK. You'll have much better luck, greater control, and no reliance on other applications. I've got a couple of DataCard printers here at work. Pretty cool little machines!

RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome

YorkTech23-Feb-05 5:22

YorkTech

23-Feb-05 5:22

Ok folks I've managed to sort this out so here's how you do it. Just in case someone else has the same trouble.

This method should work for the following manufacturers printers that allow magnetic stripe encoding via Escape codes. The snytax is slight different for each manufacture. Usually ~1 ~2 ~3 for tracks 1,2,3 respectively.

Card Printers
-------------
Eltron
Alantek
Fargo
DataCard
Victor Data Systems

*Note* This does not mean sending sending RAW data straight to the printer. The Datacard documentation explains that the print data has to be sent to the driver.

This uses the standard .net printing objects

To Encode your magstripe

'Grab the handle of the graphics object provided by the printpageeventargs
hDC = e.Graphics.GetHdc
'Set up your data
magTrack1 = "~1" & m_Card.MagTrack1
magTrack2 = "~2" & m_Card.MagTrack2
magTrack3 = "~3" & m_Card.MagTrack3
'Call the GDI ExtTextOut Routine
ExtTextOut(hDC, 10, 10, 2, Nothing, magTrack1, magTrack1.Length, Nothing)
e.Graphics.ReleaseHdc(hDC)
'Release the hdc
e.graphics.release(hDC)

Now do any other fancy graphics for your card layout and call the print event when finished. If you use a print preview you'll seen the magstripe text drawn on the screen. But it isn't printed, the printer recognises the escape codes and encodes the mag stripe.

The code for calling ExtTextOut is :-

Private Structure RECT
Public Left As Int32
Public Top As Int32
Public Right As Int32
Public Botton As Int32
End Structure
Private Declare Function ExtTextOut Lib "gdi32" Alias "ExtTextOutA" (ByVal hdc As IntPtr, _
ByVal x As Integer, ByVal y As Integer, ByVal wOptions As Integer, ByRef lpRect As RECT, _
ByVal lpString As String, ByVal nCount As Integer, ByVal lpDx As Integer) As Integer

Hope this helps someone else
Cheers
Steve. Smile | :)

coderam1-Jun-09 1:30

coderam

1-Jun-09 1:30

Steve,

I know you have done this long back. I need a small help from you on this. The below line is confusing me a lot.

premiercomputers wrote:
Now do any other fancy graphics for your card layout and call the print event when finished.

We get the printpageeventargs graphics handler only after calling the 'Print' method. So first we have to call Print event and in it we get the handler to send the magnetic strip text, then next we send card design etc. Isn't it?

Can you give us the code that above the 'hDC = e.Graphics.GetHdc' and Print event method implementation if possible.

Thanks
Ram

thread timer abort

manasrahfantom21-Feb-05 23:49

manasrahfantom

21-Feb-05 23:49

hello everyone,

im using thread timer (System.Threading.Timer) , and its working perfectly.

When i try to stop it using
MyThreadTimer.Change(System.Threading.Timeout.Infinite, System.Threading.Timeout.Infinite)

its stops , just after it finish the current task, isnt there anyway to stop it immediatly without waiting to finish its task.

Thanks in Advance
Mahmoud Manasrah

Dave Kreskowiak22-Feb-05 0:39

22-Feb-05 0:39

Once the timer Interval is set and the timer is running, you can't change the interval until the Timer fires its event and resets itself. The only way to change the interval, if the timer is already running, is to destroy the Timer, using Dispose, and recreate it with the new interval.

RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome

manasrahfantom22-Feb-05 0:57

manasrahfantom

22-Feb-05 0:57

hi again,

Dave Kreskowiak wrote:
is to destroy the Timer, using Dispose, and recreate it with the new interval.

i done this, just it didnt work

i disposed the thread and make a new instance with intial state aborted and stopped just it didnt stop until it finished.

Thanks in Advance
Mahmoud Manasrah

Dave Kreskowiak22-Feb-05 1:41

22-Feb-05 1:41

Whoops! Might have helped if a read the entire question again. I've never tried it before, but you might want to try setting the AutoResetEvent you used to create the Timer.

    Dim autoEvent As New AutoResetEvent(False)
    Dim timerDelegate As TimerCallback = AddressOf ...
 
    Dim delayTime As New TimeSpan(0, 0, 1)
    Dim intervalTime As New TimeSpan(0, 0, 0, 0, 250)
 
    Dim stateTimer As Timer = New Timer( timerDelegate, autoEvent, delayTime, intervalTime)
    .
    .
    .
    autoEvent.Set()

RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome

manasrahfantom22-Feb-05 2:07

manasrahfantom

22-Feb-05 2:07

r u sure that this is the solution!

well the problem is not in running the timer, or in calling it back...

The problem is when i stop the timer..it dont stop until it ends the current process it is doing..

like if it was sending emails for 25 persons, and i click stop, it dont stop until it send to the 25 person...just it dont callback the timer...

i want to stop the thread which the timer is executing immediatly , and not wait until its done...

Thanks in Advance
Mahmoud Manasrah

Dave Kreskowiak22-Feb-05 3:09

Re: how is creating control?

22-Feb-05 3:09

Like I said, I've never done it before. So how can I be sure that it's going to work?

You never said anything about stopping the callback method that the Timer is executing...
You'll have to rewrite your code so that this callback method checks for a flag every once in a while to tell it to stop. This has nothing to do with the Timer functionality at all!

RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome

how is creating control?

MGunes21-Feb-05 23:49

MGunes

21-Feb-05 23:49

how is creating control?

Dave Kreskowiak22-Feb-05 0:33