Visual Basic

Re: displaying checked itmes

7-Nov-06 5:00

I might be wrong but I think that the only way to do this is by writing a driver. Devices being connected/disconnected cause an interrupt at KERNEL level, and those addresses are out of bounds in user mode.

displaying checked itmes

chikumbutso5-Nov-06 6:23

chikumbutso

5-Nov-06 6:23

i have ten(10) checkboxes on my application, users can only select or check 6 of these checkboxes. i would like to be able to display those 6 checked items on 6 labels after the click of a button.

could you help me with the code for this.

chiku

Reuven Elliassi5-Nov-06 8:54

Reuven Elliassi

5-Nov-06 8:54

Do it with array of check boxes and run over it. if Chk(i).checked=true then msgbox (chk(i).text)

Printing problems in VB

MyFathersSon5-Nov-06 5:58

5-Nov-06 5:58

Hi all,
I'm trying to print out text and graphics on the same page using VB's Printer.Print

For i = 0 To List2.ListCount - 1 Step 1
Printer.Print List2.List(i)
Next i

If Clipboard.GetFormat(vbCFBitmap) Then
Printer.PaintPicture Clipboard.GetData(), 0, 0
Printer.EndDoc
End If

The graphics gets printed out, but the text from the list box doesn't. Any ideas on how I can resolve this? Thanks

MyFathersSon

OldWarhorse5-Nov-06 6:44

5-Nov-06 6:44

Looks like the graphic might be overlaying the print buffer.
I would try the simplest approach first, and put an EndDoc after the listbox loop and see if that will flush the buffer without advancing the page.
Failing that, you might have to set the text and graphics onto a Form or Picture box first, and then call PrintForm.

MyFathersSon5-Nov-06 7:09

5-Nov-06 7:09

Thanks for your suggestion. I placed a Printing.EndDoc statement as follows:

For i = 0 To List2.ListCount - 1 Step 1
Printer.Print List2.List(i)
Next i
Printer.EndDoc ' added

and this printed both text and graphic, but on separate pages. I'm not sure how to carry out your second suggestion.

MyFathersSon

OldWarhorse5-Nov-06 7:59

5-Nov-06 7:59

That's what I was afraid of...
Been a long time since I messed with that. I wish I had a good example for you, but there should be a bunch of em out there (good ol' Google).

MyFathersSon7-Nov-06 6:30

7-Nov-06 6:30

Thanks for your advice OldWarhorse. Not much on google.

ChandraRam6-Nov-06 0:53

ChandraRam

6-Nov-06 0:53

Did you try printing the graphics first?

Chandra

MyFathersSon7-Nov-06 6:28

7-Nov-06 6:28

I did but the results are the same. Thanks for your advice.

Hard drive Info

Code Crapper5-Nov-06 5:09

5-Nov-06 5:09

What would I type to get a computers Harddrive total space and used space?

I have been looking around allot and all I have found is useless VB 6 code and some jibberish in C#, can someone please help me with this.

Many Thanks Confused | :confused:

OldWarhorse5-Nov-06 5:33

5-Nov-06 5:33

System.IO.DriveInfo

Boy, you're being a P.I.A. today.

You're gonna owe me a cut of that app. Laugh | :laugh:

Code Crapper5-Nov-06 5:41

5-Nov-06 5:41

that easy!!! omg.. sorry for the dumb question Big Grin | :-D

OldWarhorse5-Nov-06 6:04

5-Nov-06 6:04

- You crack me up, Dude.
Hey, the only dumb question is the one you should have asked and didn't, right? Smile | :)

Code Crapper5-Nov-06 6:05

5-Nov-06 6:05

Ah hell now i came to another bottleneck... um (feels very stupid) how can i use this to display the actual total size of a drive because so far i can get it to say 16Bytes when it should be saying 250GB (well in that region)

OldWarhorse5-Nov-06 7:32

5-Nov-06 7:32

Try something like this:

Dim dr As New System.IO.DriveInfo("C")
Dim sizeInBytes As Long
Dim sizeInGB As Single

sizeInBytes = dr.TotalSize
sizeInGB = sizeInBytes / 1000000000
TextBox1.Text = String.Format("Total Drive Size in Bytes:  {0}", sizeInBytes.ToString("#,###,###,###,###"))
TextBox2.Text = String.Format("Total Drive Size in GB:  {0}", sizeInGB.ToString("###,###,###,###.00"))

You can play around with the verbage, divisor value, and formatting as you prefer.

Code Crapper5-Nov-06 7:46

5-Nov-06 7:46

Yes!! thanks so much for this golden nugget i been searching for something like this for ages whew

THANK YOU!! Big Grin | :-D

OldWarhorse5-Nov-06 7:56

Function; changing ByRef to ByVal

5-Nov-06 7:56

You're welcome! Big Grin | :-D

(I gotta go do some nasty work for a while now. Fighting an 8-headed datagrid monster.
Catch ya later. Happy coding.)

aqzman_5-Nov-06 3:42

aqzman_

5-Nov-06 3:42

Hey guys, I'm writing this program for a visual basic class I'm taking in college, but I can't seem to figure this out.

I have a function wrote by it passes some day ByRef, it gives me the right anwser, but I showed it to my teacher and she said I need to change it to ByVal, but when I do that it gives me an anwser of 0.

So does anyone know how I'd be able change the function to ByVal and still give me the right anwser?

Thanks

What I'm trying to change is "Function CalcOwed(ByVal Number As Double, ByRef Data As Double) As Double" to "Function CalcOwed(ByVal Number As Double, ByVal Data As Double) As Double".

Public Class Form1

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim TaxIncome, Amount, Count As Double
lstDisplay.Items.Clear()
Input(TaxIncome, Amount)
Display(Amount)
End Sub
Sub Input(ByRef TaxIncome As Double, ByRef Amount As Double)
TaxIncome = CDbl(InputBox("Enter your taxable income", , ""))
If TaxIncome > 0 Then
CalcOwed(TaxIncome, Amount)
Else
Do While TaxIncome <= 0
TaxIncome = CDbl(InputBox("Enter your taxable income, above zero this time", , ""))
Loop
CalcOwed(TaxIncome, Amount)
End If
End Sub
Sub Display(ByVal Amount As Double)
lstDisplay.Items.Add("You owe " & (FormatCurrency(Amount)))
End Sub
Function CalcOwed(ByVal Number As Double, ByRef Data As Double) As Double
Select Case Number
Case 1 To 7150
Data = Number * 0.1
Case 7150 To 29050
Data = (Number * 0.15) + 715
Case 26050 To 70350
Data = (Number * 0.25) + 4000
Case 70350 To 146750
Data = (Number * 0.28) + 14325
Case 146750 To 319100
Data = (Number * 0.33) + 35717
Case Else
Data = (Number * 0.35) + 92595.5
Return Number
End Select
Return Number
End Function
Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
Me.Close()
End Sub

Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
lstDisplay.Items.Clear()
End Sub
End Class

Re: Function; changing ByRef to ByVal

OldWarhorse5-Nov-06 4:59

Re: Function; changing ByRef to ByVal [modified]

5-Nov-06 4:59

The reason she wants you to change it to ByVal is to see if you understand the difference between passing arguments by value and passing them by reference. Obviously, you don't yet. You just skimmed over that section in the book, and you can't do that. This key point is fundamental to just about all programming languages, not just VisualBasic.

We could just show you how to change it and make it "give the right answer", but that would doing you and the industry a grave disservice.

So go back to your book, find that section, and re-read it. Several times if necessary.

This may also help.
Visual Basic Language Concepts
Differences Between Passing an Argument By Value and By Reference
http://msdn2.microsoft.com/en-us/library/eek064h4(VS.80).aspx[^]

Hint 1:
ByRef gives your procedure code a direct view back to the original variable.
ByVal gives your procedure code a COPY of, and an indirect view of, the VALUE of the original variable.

Hint 2: Why code a Function if you are just going to call it as a Sub and not use the return value from it?

Wink | ;)

aqzman_5-Nov-06 5:53

aqzman_

5-Nov-06 5:53

Thanks a lot for the help. =) I'll have another read over the chapter in my book, and thanks for the link.

As for coding the function, rather then just doing it all in the sub procedure, for some reason our teacher wants it done in a function. heh

Thanks again.

-- modified at 12:08 Sunday 5th November, 2006

Edit:

I got it working, thanks for all the help. =)

Re: Function; changing ByRef to ByVal

OldWarhorse5-Nov-06 7:34