Visual Basic Discussion Boards

Re: Reports

Stephen Lintott22-Mar-09 23:47

Stephen Lintott

22-Mar-09 23:47

Thats what I ment thanks

Stephen Lintott Bsc IT (RAU)

How do I automate a list control whenever the underlying table has an insert?

Robin Kershaw22-Mar-09 18:28

Robin Kershaw

22-Mar-09 18:28

I'm developing a client-server,(VB.Net/SQL Server) Incident Management system with up to 8 users. Each User is performing actions that generate entries in a single log table in the DB. I want each user to have a common view of all log entries, regardless of the source, updating whenever a new entry is inserted in the log. The display will be a listbox or grid control. How do I get the control automatically updated? Do I need A Broker service and async application on the client to get messages? I have seen suggestions of using managed code. I hope someone has tried this before and might suggest a way to do this.

Re: How do I automate a list control whenever the underlying table has an insert?

Eddy Vluggen22-Mar-09 22:40

Eddy Vluggen

22-Mar-09 22:40

Meaning that there is a table in your database, and you want the screen to automatically update when the table in your database changes?

A simple method would be to add a datetime-stamp to each record you insert, and doing a SELECT MAX(lastwritedate) every minute or so. That would give you the date/time that the last record was modified Smile | :)

I are troll Smile | :)

Re: How do I automate a list control whenever the underlying table has an insert?

Robin Kershaw23-Mar-09 3:37

Robin Kershaw

23-Mar-09 3:37

Thanks for the reply Eddy.
I was looking for something more "real time". The system is for a volunteer fire station HQ controlling 7 brigades. When incidents start there could be 20 or more log entries a minute as appliances are paged, go mobile and get directions for approach, etc. Each of those activities come from a different operator and I'm hoping that all operators see all entries as they are inserted in the log table. The log entries do have a datetime stamp. I was looking for a method: row inserted into the log table, vb control gets the entry and displays it at the bottom of a scrolling list as near as possible in "real time".
Thanks again for your quick reply. Smile | :)

Re: How do I automate a list control whenever the underlying table has an insert?

Dave Kreskowiak23-Mar-09 3:44

Dave Kreskowiak

23-Mar-09 3:44

Look into SQL Server Notification Services. It does exactly what you're describing.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak
Microsoft MVP
Visual Developer - Visual Basic
2006, 2007, 2008

Re: How do I automate a list control whenever the underlying table has an insert? [modified]

Eddy Vluggen23-Mar-09 3:49

Eddy Vluggen

23-Mar-09 3:49

Are the applications on the same network? If they are connected in any way then you could send a signal (of any sort) that the database has changed. If you're on a internet-connection, you could opt to use Google Talk[^] to provide instant messaging.

Happy programming Smile | :)

--edit--
I'm also going to look into the Notification Services Smile | :)

--edit2--
Not part of the Express version Frown | :(

I are troll Smile | :)

modified on Monday, March 23, 2009 4:42 PM

Convert Date to Integer

C#Coudou22-Mar-09 17:50

C#Coudou

22-Mar-09 17:50

mates,
how to convert date to integer in vb.net. I searched already in google
and test it. Convert.Int32 is not what i want.

When i code it in 
VB6/VBA: 
Dim m_lDate As Long 
m_lDate = Date
m_lDate = DateAdd("m", -1, m_lDate)
This will work.

But it VB.NET:
Dim mDate As Integer
m_lDate = Date
mDate = DateAdd("m", 1, mDate)

Got an error: 
Value of type 'Date' cannot be converted to 'Integer'

How to do that in VB.NET?
Thanks in advance

C# コードMicrosoft End User
2000-2008

「「「「「「「「「「「「「「「「「「「「「「「「「「「「
The best things in life are free
」」」」」」」」」」」」」」」」」」」」」」」」」」」」

Re: Convert Date to Integer

Christian Graus22-Mar-09 20:09

Christian Graus

22-Mar-09 20:09

What do you want the int to be tho ? Would the property that returns a value in Ticks do what you need ?

Christian Graus

Driven to the arms of OSX by Vista.

Re: Convert Date to Integer

C#Coudou22-Mar-09 20:35

C#Coudou

22-Mar-09 20:35

Christian Graus wrote:
What do you want the int to be tho ?

I need it to my function that will add date, month, and year when i press
+/- button.

Here's what i did in vba.

Function ScrollDate(FNAME As String, CTname As Control, vskip)

    Dim CTLN As Date
    CTLN = CTname
    CTLN = CTLN + vskip
    CTname = CTLN
    DoCmd.RepaintObject A_FORM, FNAME

End Function

So everytime i will click +/- button, i will call ScrollDate

Perfectly working in vba.

But in vb.net. I don't know what to do?

Re: Convert Date to Integer

Christian Graus22-Mar-09 20:42

Christian Graus

22-Mar-09 20:42

YOu mean, add two dates together ? How does this relate to having the date in a form as a single int ? What I don't get it, what format do you want, specifically, or don't you care, so long as it represents a date as an int ?

Christian Graus

Driven to the arms of OSX by Vista.

Re: Convert Date to Integer

C#Coudou22-Mar-09 21:20

C#Coudou

22-Mar-09 21:20

Christian Graus wrote:
what format do you want, specifically, or don't you care, so long as it represents a date as an int ?

yes, i don't care the format, as long as i get the int value from date value.

Example in vb6/vba:
myDate as Long
myDate = Date (2009/03/23)
so therefore myDate = 39896 (long)-->i need this in vb.net

Re: Convert Date to Integer

Christian Graus22-Mar-09 21:53

Christian Graus

22-Mar-09 21:53

OK, so ANY int value will do ? So the Ticks property I suggested you use, in my first reply, will work just fine ? DateTime.Now.Ticks

Christian Graus

Driven to the arms of OSX by Vista.

database connection dotnet with access

hari Rayala22-Mar-09 8:32

hari Rayala

22-Mar-09 8:32

how to connect msaccess database in dotnet

Re: database connection dotnet with access

DaveAuld22-Mar-09 8:39

DaveAuld

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/

Re: database connection dotnet with access

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

DaveAuld

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

Gary M

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

Re: Reading Time

George B Gilbert22-Mar-09 5:30

George B Gilbert

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.

Re: Reading Time

Gary M22-Mar-09 6:46

Gary M

22-Mar-09 6:46

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

Gary

Re: Reading Time

Gary M22-Mar-09 6:58

Gary M

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

Re: Reading Time

George B Gilbert22-Mar-09 7:43

George B Gilbert

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?

Re: Reading Time

Gary M22-Mar-09 11:43

Gary M

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!

Re: Reading Time

George B Gilbert22-Mar-09 12:17

George B Gilbert

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.

Re: Reading Time

Gary M23-Mar-09 11:55

Gary M

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

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