Visual Basic

Re: Check for keypress on timer tick

26-Apr-07 5:45

This is because you're code is checking the value of the enumeration Keys.Up against 0, which will always return true since there is no key with a scancode of 0.

Your code won't work. As there is nothing that holds the value of the last key pressed. You don't need a Timer for this. All you need to do is handle the form's KeyDown event.

Private Sub Form1_KeyDown(ByVal sender As Object, ByVal e As KeyEventArgs) Handles Me.KeyDown
    If e.KeyCode = Keys.Up Then
        MessageBox.Show("", "")
    End If
End Sub

Oh...I almost forgot. In order for the Form's Key events to work, you have to enable it's KeyPreview property. This gives the form the first look at the keys being hit, instead of the keys being sent directly to the controls on the form.

Me.KeyPreview = True

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007

RyanPotter26-Apr-07 5:53

RyanPotter

26-Apr-07 5:53

Yes, I know that you can do that, but I only want this to occur when the timer is on. Once the timer turns off I want the key to do something else. I also have other things within the timer, I just showed you the problem area. The other things in the code don't affect the outcome if this.

If I wanted to do this within my timer, how would I do that?

Re: Check for keypress on timer tick

Dave Kreskowiak26-Apr-07 6:18

Comparitive function for Format() in .NET

26-Apr-07 6:18

Exactly the same thing, but, in the KeyDown event, you'd save the KeyCode off to a class-scoped variable that you check in your If statement in the Timer Tick event.

Public Class MyForm
 
    Private LastKey As Keys
 
    Keydown Handler    
         LastKey = e.KeyCode

    Tick Handler
    If LastKey = Keys.Up Then
        ...
    End If

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007

Marcus J. Smith26-Apr-07 5:05

Marcus J. Smith

26-Apr-07 5:05

I like to be a .NET purist, meaning that if I know something is a VB6 specific function I want to try to avoid it. In doing so there are times that the work around becomes a hassle as is the case with Format(). Say I have a string strValue = "0001" and I want to add some characters around it and within it. If I were to say use Format(strValue, "**000/0**) I believe I would end up with "**000/1**". What is the equivalent of that with .NET without concatenating strings? String.Format() gives a different output.

_Cle^aKO

"I think you'll be okay here, they have a thin candy shell. 'Surprised you didn't know that.'" - Tommy (Tommy Boy)
"Fill it up again! Fill it up again! Once it hits your lips, it's so good!" - Frank the Tank (Old School)

Re: Comparitive function for Format() in .NET

Dave Kreskowiak26-Apr-07 5:40

Re: Comparitive function for Format() in .NET

26-Apr-07 5:40

CleaKO wrote:
strValue = "0001"

CleaKO wrote:
Format(strValue, "**000/0**)

The old string formatting characters in VB6, I think the whole set was "@&<>!", are no longer supported in VB.NET. They've been supplanted with something like this:

Debug.Print(String.Format("**000{0,8}0**", "ABC123"))
 
Results:
    **000  ABC1230**

Or, for a left-justified field:

Debug.Print(String.Format("**000{0,-8}0**", "ABC123"))
 
Results:
    **000ABC123  0**

The 8 and -8 just say that this field, whatever ends up in it, must be 8 characters wide and should be padded with spaces. The 0 means that this is the placeholder for the first expression argument.

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007

mabo4226-Apr-07 5:40

mabo42

26-Apr-07 5:40

Not sure, what you are trying to accomplish, but if you use the numeric value of strValue, it would be something like that:

string s = "0001";
s = string.Format("**{0:000/0}**", Convert.ToInt32(s));

Sorry that's c#, assume similar syntax for VB.

Hope that helps.

Treeview Topnode problem

dBrong26-Apr-07 5:02

dBrong

26-Apr-07 5:02

I build a treeview from data sorted alpha. Everything works fine, looks fine.

However treeview.topnode.ensurevisible() is at about the 4 th node.

Treeview.Nodes(0).Ensurevisible() works!

Does anyone know what property VB uses to determine the top node?

Re: Treeview Topnode problem

Dave Kreskowiak26-Apr-07 5:19

Re: Treeview Topnode problem

26-Apr-07 5:19

It sounds like you've assumed that TopNode returns the root node of the Tree. Reading the documentation tells you what is really means. TopNode returns the first fully-visible node displayed in the TreeView.

And it's not VB that makes this determination, it's the code in the TreeView code in the .NET Framework.

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007

dBrong26-Apr-07 14:05

dBrong

26-Apr-07 14:05

Silly me, I assumed the top node was the Top Node! Thanks for the clarification.

CodeDom : How to write #region blocks?

Duncan Edwards Jones26-Apr-07 3:46

Duncan Edwards Jones

26-Apr-07 3:46

I am using CodeDom to write some code.

e.g. To create a class:-

<br />
    Dim _generator As System.CodeDom.Compiler.ICodeGenerator<br />
    Dim _writer As System.IO.TextWriter<br />
    Dim _codeGenOptions As System.CodeDom.Compiler.CodeGeneratorOptions<br />
<br />
        'Set the desired language to vb<br />
        Dim foo As New Microsoft.VisualBasic.VBCodeProvider<br />
        _generator = foo.CreateGenerator("C:\duncan.vb")<br />
<br />
<br />
        'Set the code generation options to be used when creating this class<br />
        _codeGenOptions = New System.CodeDom.Compiler.CodeGeneratorOptions<br />
        _codeGenOptions.BlankLinesBetweenMembers = True<br />
        _codeGenOptions.VerbatimOrder = False<br />
<br />
        If Not _generator Is Nothing Then<br />
            _writer = New System.IO.StreamWriter(fi.FullName)<br />
<br />
            Dim _myDocumentClass As New CodeTypeDeclaration("DuncansClass")<br />
            _myDocumentClass.Attributes = MemberAttributes.Public<br />
            _myDocumentClass.Comments.Add(New CodeCommentStatement(" Created " & System.DateTime.Now.ToString))<br />
<br />
                        Dim _txtmember As New CodeMemberField<br />
                        _txtmember.Type = New CodeTypeReference("System.String")<br />
                        _txtmember.Attributes = MemberAttributes.Private<br />
                        _txtmember.Name = _generator.CreateValidIdentifier("_Duncan_Text")<br />
                        _txtmember.Comments.Add(New CodeCommentStatement("Text to use here "))<br />
                        _myDocumentClass.Members.Add(_txtmember)<br />
<br />
        End If<br />
<br />
_generator.GenerateCodeFromType(_myDocumentClass, _writer, _codeGenOptions)<br />

which creates the code:

<br />
'Created 2007-04-21<br />
Public Class DuncansClass<br />
<br />
   'Text to use here<br />
   Private _Duncan_text As String<br />
   <br />
End Class<br />

Any Ideas as to how I could put the private member declaration in a region using codeDom?
e.g.

<br />
'Created 2007-04-21<br />
Public Class DuncansClass<br />
<br />
  #Region "Private members"<br />
   'Text to use here<br />
   Private _Duncan_text As String<br />
   #End Region<br />
<br />
End Class<br />

'--8<------------------------
Ex Datis:
Duncan Jones
Merrion Computing Ltd

Re: CodeDom : How to write #region blocks?

Dave Kreskowiak26-Apr-07 6:49

Re: CodeDom : How to write #region blocks?

26-Apr-07 6:49

Could you be looking for the CodeRegionDirective[^] class? Be careful, not all languages support Regions!

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007

Duncan Edwards Jones26-Apr-07 22:19

Duncan Edwards Jones

26-Apr-07 22:19

Excellent - that did the trick, thanks...

'--8<------------------------
Ex Datis:
Duncan Jones
Merrion Computing Ltd

Re: CodeDom : How to write #region blocks?

Dave Kreskowiak27-Apr-07 10:11

List box ordering at run time

27-Apr-07 10:11

Any time!

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007

samerh26-Apr-07 3:35

samerh

26-Apr-07 3:35

Hi all,
I have a case where i bounded data to a list box in a windows application and i want to place a button in that form so that i can move the items up or down. Moreover i want to maintain that order when i leave the form and enter it again.
Thanks

Re: List box ordering at run time

samerh26-Apr-07 4:07

samerh

26-Apr-07 4:07

Guys i managed to move the listbox items up and down but i need to maintain that new state. How can i?

CD\DVD-rom

Xmen Real 26-Apr-07 2:31

26-Apr-07 2:31

What will the coding for eject and load CD\DVD ROM???

leckey26-Apr-07 4:33

leckey

26-Apr-07 4:33

You will probably not find someone who will just give you the code. Try searching or writing your own, then when you have a specific question/problem repost the question with the specific problem.

__________________
Bob is my homeboy.

Dave Kreskowiak26-Apr-07 4:59

26-Apr-07 4:59

Google results for "vb.net eject cd[^]".

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007

Xmen Real 26-Apr-07 5:00

26-Apr-07 5:00

thanks;)

Xmen Real 26-Apr-07 6:15

26-Apr-07 6:15

i downloaded some examples, all were in C sharp and working good but when i convert the codes to vb.net, then its giving two errors

Error	1	'Shared' is not valid on a Declare.<br />

Error 2 'System.Runtime.InteropServices.DllImportAttribute' cannot be applied to a Declare.

errors are in following code

<DllImport("winmm.dll", EntryPoint:="mciSendStringA")> _<br />
   Public Shared Declare Sub mciSendStringA Lib "winmm.dll" Alias "mciSendStringA" (ByVal lpstrCommand As String, ByVal lpstrReturnString As String, ByVal uReturnLength As Long, ByVal hwndCallback As Long)

someone know why this is happening???

Dave Kreskowiak26-Apr-07 6:35

26-Apr-07 6:35

You don't need the Shared modifier, get rid of it. You also don't need the DLLImport attribute. It's specific to C# code. And those Long's should be Integer's. This tell's me that you converted VB6 AND C# code to VB.NET. The Declare should look like this:

Private Declare Function mciSendStringA Lib "winmm.dll" ( _
    ByVal lpstrCommand As String, ByVal lpstrReturnString As String, _
    ByVal uBufferLength As Integer, ByVal hwndCallback As IntPtr) As Integer

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007

Xmen Real 26-Apr-07 14:40