Visual Basic

Daniel Turini8-Apr-05 6:11

Daniel Turini

8-Apr-05 6:11

Sub Easy()
Dim i as Integer
   i = 1
End Sub

Hope that helps.

I see dead pixels
Yes, even I am blogging now!

GizzoF8-Apr-05 6:14

GizzoF

8-Apr-05 6:14

Could you post a difficult one?

vertig07308-Apr-05 6:15

8-Apr-05 6:15

me.close

thats it

form1_load
me.close

James Kennelly

Daniel Turini8-Apr-05 6:23

Daniel Turini

8-Apr-05 6:23

GizzoF wrote:
Could you post a difficult one?
Explain me the difference between "On Error GoTo 0" and "On Error GoTo -1", with your words, without quoting MSDN.

I see dead pixels
Yes, even I am blogging now!

rwestgraham8-Apr-05 12:37

rwestgraham

8-Apr-05 12:37

Daniel Turini wrote:
Explain me the difference between "On Error GoTo 0" and "On Error GoTo -1", with your words, without quoting MSDN.

In VB6 :

On Error GoTo 0 disables any error handler in the function the GoTo 0 statement appears in. Since the error will not be trapped in the function it will be propagated up the call stack.

On Error GoTo -1 is not a valid statement because -1 is not a valid line number and is also not a valid name for an error handler section.

The VB6 compiler will not complain about an On Error GoTo -1 statement. It simply will not do anything.

In VB.NET it is the same as VB6:

On Error GoTo 0 disables any error handler in the function the GoTo 0 statement appears in. Since the error will not be trapped in the function it will be propagated up the call stack.

On Error GoTo -1: The MSDN says this "sets the enabled exception to Nothing" but if you test in code, like in VB6 On Error GoTo -1 does absolutely nothing.

The better question would be:

"What difference does On Eror GoTo -1 make in the first place because why are you using unstructured error handling in VB.NET?"

Mitch F.8-Apr-05 10:51

Mitch F.

8-Apr-05 10:51

Actually, that is quite inefficient... You could optimize the code by making it:

Sub Easy()
  Dim i as Integer = 1
End Sub

Programmer2k4

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Mitch F.8-Apr-05 10:54

Mitch F.

8-Apr-05 10:54

If you want to learn VB .Net, I'd suggest getting a book. If you do want to spend a few more hours instead of paying money, try and teach yourself VB .Net.

Some good starter points are: Event Handlers, MessageBox class, changing location/size of items programatically/at run time, and loading pictures from Embedded Resources.

People don't usually give code to an entire application away for free, and also, you haven't really asked a question therefore I am really unable to answer directly to your needs from what you already know.

Try a search on google for "VB .Net Beginner Tutorials" and such, and you will get helpful tutorials.

And of course, check the VB .Net articles section of this site! Green Alien | [Alien]

I hope this helps,

Programmer2k4

My sig:

"And it is a professional faux pas to pay someone else to destroy your computer when you are perfectly capable of destroying it yourself." - Roger Wright

I now use my CodeProject Blog!
Most recent blog post: April 3

jtart210-Apr-05 12:32

jtart2

10-Apr-05 12:32

I'm a beginner too.

I purchased a large book called "Mastering Visual Basic.Net" and a small one called "Visual Basic.Net in Easy Steps" . The small book cost $10 and gave me clear examples and showed me how to do basic things...enought to let me write my own first semi-complex program.
The large book cost $50 and was full of definitions with a few abstract examples. The cheap, small book is so much better. If I were you, I'd get that one..."Visual Basit.Net in Easy Steps"
Good luck. Confused | :confused:

If you make yourself a sheep, the wolves will eat you!!!!!!!!!!

vb concept

feeha8-Apr-05 4:55

feeha

8-Apr-05 4:55

i have a small project of multilease project
in that i want to add vehicle,delete and edit and save the following vehicle
for xample if a salesman selects toyata camry he hsould be able to add the vehicle,delete vehicle ,edit vehicle and save vehicle
ho should i write using a vb code

aaffi

Re: vb concept

vertig07308-Apr-05 5:30

8-Apr-05 5:30

Please tell me you are joking!

James Kennelly

Re: vb concept

GizzoF8-Apr-05 5:40

GizzoF

8-Apr-05 5:40

I can't stop laughing.
Laugh | :laugh:

Windows Service

H@is@here8-Apr-05 4:41

H@is@here

8-Apr-05 4:41

Hello

I' have a problem with starting a windows service programmed in VB.Net

In all OS (win2000 and upper) the service runs sucessfully ,but in one specific computer with (win2000 Server) the service give's me this error:

Service cannot be started. System.InvalidCastException: Cast from string "4/" to type 'Integer' is not valid. ---> System.FormatException: Input string was not in a correct format.
at Microsoft.VisualBasic.CompilerServices.DoubleType.Parse(String Value, NumberFormatInfo NumberFormat)
at Microsoft.VisualBasic.CompilerServices.IntegerType.FromString(String Value)
--- End of inner exception stack trace ---
at Microsoft.VisualBasic.CompilerServices.IntegerType.FromString(String Value)
at RufosFileWatcher.RufosFileWatcher.OnStart(String[] args)
at System.ServiceProcess.ServiceBase.ServiceQueuedMainCallback(Object state)

Can someone help me on this ??

Thanks

Dave Kreskowiak8-Apr-05 4:51

Dave Kreskowiak

8-Apr-05 4:51

It looks like the command line arguments you supplied to start the service don't have a space in them where one should be. Mind you, this is a wild guess based soley on the stack trace you posted.

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

H@is@here8-Apr-05 5:24

H@is@here

8-Apr-05 5:24

Thanks for your reply

OK but I don´t pass any arguments to start the service.
Do you mean OnStart(String[] args)?

I just use the installutil -i (Service name)
and to start the service I use the serviceController:

Dim Myservice as new ServiceController("Name of the service")
Myservice.start
MyService.Refresh

But if I use the start in the services panel it give´s me the same error.

Thanks

Dave Kreskowiak8-Apr-05 8:53

Dave Kreskowiak

8-Apr-05 8:53

It looks like it's complaining about something in your OnStart code. Is this .EXE known to be exactly the same as the copies on the other machines? Does the machine have the correct version of the .NET Framework and any service packs on it?

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

Deleting a row in a datatable

H@is@here8-Apr-05 10:55

H@is@here

8-Apr-05 10:55

Yes it is the same deployment cd of the other machines.

About the .Net Framework:

That is what i am suspecting. The framework installed is the 1.1 but I don´t know if it has any service packs.

I will try that!

Thanks Dave

Martin@captivasystems8-Apr-05 4:19

Martin@captivasystems

8-Apr-05 4:19

How can I delete a row from a datatable based on a condition.
Here is what I'm trying to do:

Dim row As DataRow
For Each row In Table1.Rows
If (row("Name") = "Adam") Then
Table1.Rows.Remove(row)
End If
'MsgBox(row("Name"))
Next

Thanks,
Martin

vertig07308-Apr-05 4:30

8-Apr-05 4:30

put this in a click command dont forget to put in your binding manager, data adapter and dataset

dimdgrdelete as dialogresult

try
dgrdelete = messagebox.show("delete this record?", _
"Confirm Delete",Messageboxbuttons.YesNo)

if dgrdelete = dialogresult.yes then
with bmanager 'bindingmanager
.removeat(.postion)
end with
daAdapter.update(dsDataset)
dsDataset.acceptchanges
end if

catch err as exception
messagebox.show(err.message)
end try

James Kennelly

vertig07308-Apr-05 4:31

8-Apr-05 4:31

oopps

dim dgrdeleteas dialogresult

James Kennelly

Martin@captivasystems8-Apr-05 5:30

Martin@captivasystems

8-Apr-05 5:30

I wasn't able to replicate your example, I never worked with the binding manager. Below is what I did. Is there a more efficint way?

Dim row As DataRow
Dim i As Int16 = 0
Dim ar As ArrayList = New ArrayList()
For Each row In Table1.Rows
If (row("Name") = "Adam") Then
ar.Add(i) 'add the index of the row to be deleted
End If
i = i + 1
Next
Dim index As Int16
For index = 0 To ar.Count - 1
Table1.Rows.RemoveAt(ar.Item(index))
Next

datagrid1.SetDataBinding(Table1, Nothing)
datagrid1.RetrieveStructure()

Guillermo Rivero8-Apr-05 6:00

Guillermo Rivero

8-Apr-05 6:00

<br />
Dim rows() as DataRow<br />
<br />
rows = Table1.Select(" Name = 'Adam' ")<br />
<br />
If rows.Length > 0 Then<br />
   Table1.Rows.Remove(rows(0))<br />
End if<br />

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