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I have written a class in C++ and would like to define it as a variable data type in VB. How should I go about it??
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Chances are you're going to do a little rewriting of your class. But your question would be better handled in the Visual C++ forum as I THINK(!) your going to be exposing it to COM so VB can see and use it.
RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome
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I am attempting to write a program that will list the running processes on a computer. I currently have a listView box that stores the running processis as items in the ListView. The ListView must update every so often (2 secons or so).
But when it updates it must check to see if a process is already contained in the list. For example there are usually four or so processes with the name svchot.exe, so we must make sure that we also check the PID (a subitem for each item that stores the "Process ID").
My problem is that when I attempt to check if an item is in the listView, it is not found. Here is the coded snipet in question.
'Takes three parameters: lvw is the ListView that contains all of the items,
'item_title is the name of the item we want to add (process name),
'subitem_titles() is an array of strings containing the subitems (PID, CPU time...) Private Sub ListViewMakeRow(ByVal lvw As ListView, ByVal ProcessName As String,_ ByVal ParamArray subitem_titles() As String)
'Temporary ListViewItem used to create a lvw
Dim ListItemTemp As New ListViewItem(ProcessName)
'check to see if our TempListItem is found in lvw
'At least that is what it is supposed to do.
If Not (lvw.Items.Contains(TempListItem)) Then
Dim new_item As ListViewItem = lvw.Items.Add(ProcessName)
For i As Integer = subitem_titles.GetLowerBound(0) To _
subitem_titles.GetUpperBound(0)
new_item.SubItems.Add(subitem_titles(i))
Next i
Else
End If
End Sub
At the moment I am only trying to see if I can check to see if the item is already in the ListView. Later on I will add more checks to see if it is a different process.
Currently the process will continue to add more items to the list even if the item is found in the list. I am not able to debug it to see which items are already in the list and to see if it is making the correct decision. However I know that it does not work because every half a second or so another item with the same name is added to the list (every second a process named “explorer.exe” is added… and so on for each process that runs.
So the question is can anyone point me to a good tutorial on the:
ListView.ListViewItemCollection.Contains
or to some other way of checking the ListView. I have looked at microsofts inof for the ListView class
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpref/html/frlrfsystemwindowsformslistviewitemlistviewsubitemclasstopic.asp
however their example does not use the Contains method.
I will attempt to use GetIndexOf. However I am not sure how that would work if there are multiple items with the same name.
Thanks in Advance
Donald Carlson, Jr.
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Unfortunately it is a bit ineficent and lacks the update capabilities, however it does properly check to see if an item with the same name exists and also checks to see if an item with the same subitem exists (assuming there are more then one item with the same name). IF you have any improvements or other ideas pleas feel free to post them.
Private Sub ListViewMakeRow(ByVal lvw As ListView, ByVal ProcessName As String, ByVal ParamArray subitem_titles() As String)
'Creates a temporary listViewItem
Dim CurrentListItem As ListViewItem
'check to see if our TempListItem is found in lvw
If (lvw.Items.Count = 0) Then
'there are no entries in the list (list is empty)
Dim new_item As ListViewItem = lvw.Items.Add(ProcessName)
For i As Integer = subitem_titles.GetLowerBound(0) To _
subitem_titles.GetUpperBound(0)
new_item.SubItems.Add(subitem_titles(i))
Next i
Else
'Well apparently the list is not empty
Dim dataListEnumerator As IEnumerator = lvw.Items.GetEnumerator()
Dim containsItem As Boolean = False
Dim PID As String
'check all entries in the list
While (dataListEnumerator.MoveNext())
CurrentListItem = CType(dataListEnumerator.Current, ListViewItem)
' Display the current DataListItem onto the label.
If (ProcessName = CurrentListItem.Text) Then
containsItem = True
'Stores the PID for later checking if needed
PID = PID & " " & CurrentListItem.SubItems.Item(1).Text
End If
End While
If (containsItem = False) Then
'this process is not found in the list
Dim new_item As ListViewItem = lvw.Items.Add(ProcessName)
For i As Integer = subitem_titles.GetLowerBound(0) To _
subitem_titles.GetUpperBound(0)
new_item.SubItems.Add(subitem_titles(i))
Next i
Label2.Text = "sweet unnion rings"
ElseIf (PID.IndexOf(subitem_titles(0)) = -1) Then
'this specific process with this specific PID is not found
'Assumes that contansItem is true
Dim new_item As ListViewItem = lvw.Items.Add(ProcessName)
For i As Integer = subitem_titles.GetLowerBound(0) To _
subitem_titles.GetUpperBound(0)
new_item.SubItems.Add(subitem_titles(i))
Next i
End If
End If
End Sub
Donald Carlson, Jr.
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Hi all
I am trying to convert a html page (home.htm) to an asp page (home.aspx). Please can anyone show me how to work this out?
Thanks very much for help!
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Well, that depends on what you want to do. The best thing would be to copy and paste your page into the aspx, between the form tags, then go through and replace all controls with aspx controls. The easy way is to keep the old html controls, but then why would you convert to aspx anyhow ?
Christian
I have several lifelong friends that are New Yorkers but I have always gravitated toward the weirdo's. - Richard Stringer
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Thanks for help, Christian!
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Howdy.
I have a program with 4 different listviews.
I have also created a context menu that contains tasks that should be possible to perform in the different listviews.
In the four different listviews the exact same tasks should be performed so I need only one context menu, but how do I know which listview the call comes from when the context menu is activated?
I.E:
Private Sub listView_MouseUp(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles ListView1.MouseUp, ListView2.MouseUp, ListView3.MouseUp, ListView4.MouseUp
' Checking the Mouse right Button
If e.Button = MouseButtons.Right Then
Dim myLV As ListView = sender
myLV.ContextMenu.Show(sender, New Point(e.X, e.Y))
End If
End Sub
and then:
Private Sub MenuItem17_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MenuItem17.Click
listview_that_the_menu_was_started_in.Items.Clear()
End Sub
How do solve?
Thanks for assistance.
Anders Liden
Gothenburg, Sweden.
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Hi to ALL,
Can anybody help me in telling the difference between the CreateObject function and New method
Thanks to ALL
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CreateObject requires a COM typeID ( from memory, I'm sure it's not a GUID ), and spins up a COM object. new just creates an object within your code.
Christian
I have several lifelong friends that are New Yorkers but I have always gravitated toward the weirdo's. - Richard Stringer
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Hello,
In this Web site the following article was published: "Hacking the Combo Box to give it horizontal scrolling By Tomas Brennan".
It is possible to do using it VB 6.0?
Thanks.
This is the direction of the article: http://www.codeproject.com/cs/combobox/ComboHack.asp
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Hi,
I have been banging my head on a wall with this one. I'm trying to open a form from that I know the name of. This is not as easy as it might first sound.
This is the normal way of opening a form:
dim formCustomers as new frmCustomers<br />
formCustomers.Show()
That is easy! But what I want is something like this:
dim formName as String ' This is the name of an actual form that exists<br />
dim newForm as Form<br />
<br />
newForm.Name = formName<br />
newForm.Show
If I set newForm = new Form then this opens a form, but not the form that I want to open! It opens up a completly new form.
Can anyone help me here?
I am puzzled 
Thanks
Shawn
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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
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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
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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
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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.
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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
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Yes I thought that may be the case 
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.
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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
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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.
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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
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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
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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
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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
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