Visual Basic

Re: database connection dotnet with access

22-Mar-09 8:39

a) By searching google and following the thousands of examples.

b) By reading the help manuals

c) By searching this site, i doubt you are the first to ask!

Dave
Who am I?: http://www.bebo.com/daveauld/

dan!sh 22-Mar-09 9:19

dan!sh

22-Mar-09 9:19

It took you 7 minutes here and still no direct answer. While, googling would have taken less than a minute.

जय हिंद

Problem related to sorting of Listview

nazimghori22-Mar-09 8:15

nazimghori

22-Mar-09 8:15

hello every one...

i want to sort particular column of Listview on click of label

for that i wrote code in label mouse click event:-

Private Sub lbl2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles lbl2.Click

        Try
            Me.lst1.Sorting = SortOrder.Descending
           
        Catch ex As Exception
            MsgBox(ex.ToString)
        End Try

    End Sub

but this code sorts the whole listview but i want to sort particular column

of Listview....and for that this code doesn't work...

so please suggest me what to do...
Smile | :)

DaveAuld22-Mar-09 8:48

22-Mar-09 8:48

Here is a ms article on doing it in VS2005,

http://msdn.microsoft.com/en-us/kb/kb00319399.aspx[^]

Dave
Who am I?: http://www.bebo.com/daveauld/

Reading Time

Gary M22-Mar-09 3:47

22-Mar-09 3:47

I am programming in VB.NET.

I have a csv comma delimited file with this data in it.

1212.5,10:01:56,2
1212.25,10:01:59,1
1212.5,10:02:00,1
1212.25,10:02:01,1
1212.5,10:02:04,7
1212.25,10:02:04,2
1212.5,10:02:05,2
1212.25,10:02:07,16
1212.5,10:02:10,1
1212.25,10:02:10,1
1212.5,10:02:11,1

I read the second field, which is the time field into this structure TickData(i).dTime.Str But I can't figure out how to put the hour into TickData(i).dTime.H and the minute into TickData(i).dTime.M and the seconds into TickData(i).dTime.S.
My structure's are as follow.

Structure TickTime
Dim H As Single
Dim M As Single
Dim S As Single
Dim Str As String
End Structure

Structure TickD
Dim CPrice As Double
Dim dTime As TickTime
Dim Vol As Double
End Structure

Could someone Please help!

Thank You

Gary

George B Gilbert22-Mar-09 5:30

22-Mar-09 5:30

The key is the Split method.

Dim timeParts() as string
timeparts = TickData(i).dTime.Str.Split(":")
TickData(i).dTime.H = Ctype(timeParts(0), Single)
TickData(i).dTime.M = Ctype(timeParts(1), Single)
TickData(i).dTime.S = Ctype(timeParts(2), Single)

Unless there's a reason for using Single in the Structure for the time elements, you might want to save some bytes, and eliminate any possible rounding issues by using Integer or even Short.

Gary M22-Mar-09 6:46

22-Mar-09 6:46

Thank You very much. I will try this right away!

Gary

Gary M22-Mar-09 6:58

22-Mar-09 6:58

I tried it but this is the error I got.

System.NullReferenceException was unhandled
Message="Object reference not set to an instance of an object."
Source="TickChart"
StackTrace:

/////////////////////////////////////////////////////////////////////////////

This is how I did the loop!

Dim timeParts() As String
For i = 1 To UBound(TickData)
timeParts = TickData(i).dTime.Str.Split(":")
TickData(i).dTime.H = CType(timeParts(0), Single)
TickData(i).dTime.M = CType(timeParts(1), Single)
TickData(i).dTime.S = CType(timeParts(2), Single)
Next

George B Gilbert22-Mar-09 7:43

22-Mar-09 7:43

Looks like a confusion of variable names. The object "TickChart" has apparently not been instantiated. I don't see "TickChart" anywhere in this discussion except in the unhandled exception. I may have caused the problem by using "TickData" in my code. Should that be "TickTime" instead?

Gary M22-Mar-09 11:43

22-Mar-09 11:43

Here is how I started

Structure TickTime
        Dim H As Single
        Dim M As Single
        Dim S As Single
        Dim Str As String
    End Structure

    Structure TickD
        Dim CPrice As Double
        Dim dTime As TickTime
        Dim Vol As Double
    End Structure

Public TickData() As TickD 'price data array

Then I loaded the data into TickData in a LoadData sub

Sub LoadData()

ReDim TickData(50)

end sub

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim i As Integer

        Dim timeParts() As String
        For i = 1 To UBound(TickData)
            timeParts = TickData(i).dTime.Str.Split(":")
            TickData(i).dTime.H = CType(timeParts(0), Single)
            TickData(i).dTime.M = CType(timeParts(1), Single)
            TickData(i).dTime.S = CType(timeParts(2), Single)
        Next
end sub

But I still get that same error from the above Bold Text!

George B Gilbert22-Mar-09 12:17

22-Mar-09 12:17

1. Looks like there is a possible scope issue. Try making both of the Structures and all of their components Public. E.g.:

Public Structure TickTime
    Public H As Single
    Public M As Single
    Public S As Single
    Public Str As String
End Structure

2. All arrays in .NET are zero based. Your For...Next loop starts at 1. You might also use the .NET version for getting array bounds. With the below changes the loop will look at all 51 of the array elements.

For i = 0 To TickData.GetUpperbound(0)

3. I'm assuming there is more code in the LoadData sub other than the Redim statement. Are all 51 elements (including TickData(0)) of the TickData array being populated? If not, that could also cause the error. If there is less than 51 data records being read into the array, the size of the TickData array cannot be larger than the number of data records minus 1.

Gary M23-Mar-09 11:55

23-Mar-09 11:55

Thanks alot George, I was trying to read more elements than I had, which was causing the error. Now I will be using TickData.GetUpperbound(0).

Thanks again

Gary

George B Gilbert23-Mar-09 16:28

23-Mar-09 16:28

Excellent! Good job!

0x3c022-Mar-09 7:01

0x3c0

22-Mar-09 7:01

Look into the DateTime.ParseExact function. You may also need to look into the format specifiers

Gary M22-Mar-09 11:45

How to save file to particular location in VB

22-Mar-09 11:45

Thanks you I will do that.

manni_n22-Mar-09 3:16

manni_n

22-Mar-09 3:16

I am not a VB programmer.
But have to create a macro in excel sheet which uses VB code.
Actually on closing of Excel sheet i have a message box which asks to save the file.
In that i am not able to make VB code to save the file to particular location.
Can anybody provide me VB code so that i can save excel file to desired or predefined location.
I have tried some codes from net but they are not working.
Please help me out as whole module on which i am being working from one week is stuck because of this.
Thanks in advance.

Re: How to save file to particular location in VB

DaveAuld22-Mar-09 21:09

Problem while executing client-server program

22-Mar-09 21:09

The workbook object has a close method that has save changes parameter and a filename paramater.

Suspect you need to use that somehow.

Dave
Who am I?: http://www.bebo.com/daveauld/

Gagan.2021-Mar-09 18:35

Gagan.20

21-Mar-09 18:35

Hi all...

I have created a client-server program in VB.Net to rum on LAN. Since I started my project in Windows Vista Ultimate, program run normally. Now the same program,without any changes, I tried to run on Windows XP SP2 (which have already installed VS2005), it gave an error while connecting to server. The error message is : "a socket operation was attempted to an unreachable host".

Suggest me how to solve this problem.

Thanks.

Gagan

Re: Problem while executing client-server program

DaveAuld21-Mar-09 21:28

Problem with catching exceptions

21-Mar-09 21:28

Are the computers on the same networks?

Ignore your application for a moment, can you ping the target from the command prompt? If you cannot do that from windows, then your app won't see the target.

Dave
Who am I?: http://www.bebo.com/daveauld/

Badmafia21-Mar-09 14:57

Badmafia

21-Mar-09 14:57

I'm trying to validate that all boxes are filled in by the user and not left blank.

'check for missing data
        Try
        Catch TitleException As Exception
            If txtbxMovieTitle.Text = "" Then
                MessageBox.Show("Please enter a movie title.", "Data Entry Error", _
                        MessageBoxButtons.OK, MessageBoxIcon.Exclamation)
            End If
            With txtbxMovieTitle
                .Focus()
                .SelectAll()
            End With
        End Try
        Try
        Catch DataException As Exception
            If radbtnDVD.Checked = False Or radbtnVHS.Checked = False Then
                MessageBox.Show("Please select a movie type.", "Enter movie type", _
                                 MessageBoxButtons.OK, MessageBoxIcon.Exclamation)
            End If
        End Try

Re: Problem with catching exceptions

nlarson1121-Mar-09 15:45

nlarson11

21-Mar-09 15:45

i think your a little confused. Within your try is where you put your logic that could cause the app to "blow up" the catch is where you want to control what happens if the blow up occurs.

Ex:

try
    'do you test here
catch ex as exception
    'tell the user what happened by showing the exception
    msgbox(ex.tostring)
    exit sub
end try

'Never argue with an idiot; they'll drag you down to their level and beat you with experience.' ~ anonymous

'Life's real failure is when you do not realize how close you were to success when you gave up.' ~ anonymous

Re: Problem with catching exceptions

George B Gilbert21-Mar-09 16:45

How could you select an item in listview from a different tabpage?

21-Mar-09 16:45

I've found that the simplest method for testing whether a textbox has been populated by the user is to test the length of the text.

If Textbox1.Text.Length <= 0 then
    Msgbox("An entry is required in Textbox1")
    Textbox1.Focus
    Exit Sub
End If

If spaces are also an invalid entry, a simple addition handles that case as well.

If Textbox1.Text.Trim.Length <= 0 then
    Msgbox("An entry is required in Textbox1")
    Textbox1.Focus
    Exit Sub
End If

JUNEYT21-Mar-09 13:48

JUNEYT

21-Mar-09 13:48

Hi,

I have a tabcontrol with 2 tab pages. First tab page has a populated listview control and 2nd tabpage I have a button. My aim is to select the 3rd item in the listview when I clik a button in 2nd tabpage. However I also want to highlight the selected item in listview. Therefore when I go back to 1st tab page from 2nd, the listview should got focused and the 3rd item should be higlighted. How could you do that?

When I primitavely select the item in listview (in code) while I am in 2nd tabpage, the item is not getting selected and no highlight of course.

Thanks.

What a curious mind needs to discover knowledge is noting else than a pin-hole.

Re: How could you select an item in listview from a different tabpage?

George B Gilbert21-Mar-09 17:41