Re: adding to access database - Visual Basic Discussion Boards

ScreenSaver's child process dies a-borning

jim_taylor13-Mar-07 8:50

13-Mar-07 8:50

I wrote a screen saver using the starter kit that came with VB 2005 Express. Worked great! Then I wanted it to kick off an application when it ended, thus:
.
.
'Code here validates a password
.
.
Process.Start("AppPath", "Params")
Thread.Sleep(2000)
Close()

With the screensaver active, I move the mouse. It asks for the secret word. I type the word. The application pops up. Two seconds later the screen saver and the application die together.

When I run the screen saver from the command line it works the way I want it to.

What do I have to do to make it work that way in screen saver mode?

JimT

Re: ScreenSaver's child process dies a-borning

Marcus J. Smith13-Mar-07 9:05

Marcus J. Smith

13-Mar-07 9:05

Doesnt Windows control the activation/de-activation of screensavers? You probably have to dive deeper into the Windows APIs in order to control that behavior.

_Cle^aKO

"I think you'll be okay here, they have a thin candy shell. 'Surprised you didn't know that." - 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: ScreenSaver's child process dies a-borning

jim_taylor13-Mar-07 12:16

jim_taylor

13-Mar-07 12:16

The screen saver problem turns out to be one of ownership. If the operating system starts the screen saver because of inactivity, it is owned by the system, and it, along with everything it owns, goes in the dumper when some activity causes it to close. If you start it from the command line, or by clicking on it in Windows Explorer, or by clicking the preview button, you own it and it acts just like any other program; if it starts a child process, the child continues after the parent dies.

The problem, then, is to convince the OS that the child process does not belong to its parent. This is done by setting the UserName and Password parameters in the StartInfo structure before starting the child process. The only difficulty is that StartInfo.Password is not a System.String but a Security.SecureString, that is, it’s encrypted, so it takes a little doing to create it.

Re: ScreenSaver's child process dies a-borning

Marcus J. Smith14-Mar-07 3:05

Marcus J. Smith

14-Mar-07 3:05

Did you just reply to yourself with the answer? Laugh | :laugh:

Re: ScreenSaver's child process dies a-borning

jim_taylor14-Mar-07 4:02

jim_taylor

14-Mar-07 4:02

I was so desperate I was forced to think about it.

Re: ScreenSaver's child process dies a-borning

Marcus J. Smith14-Mar-07 9:45

Marcus J. Smith

14-Mar-07 9:45

Well good job, now if I ever have the issue, Ill just refer to your reply to yourself. Poke tongue | ;-P

adding to access database

peteyshrew13-Mar-07 6:54

peteyshrew

13-Mar-07 6:54

right now i'm trying to add data to a database. i think i'm almost their but get this error message

"Property access must assign to the property or use its value"

this is what code i got

Imports System.Data.OleDb
Public Class Cust
Inherits System.Windows.Forms.Form
Dim cn As OleDbConnection
Dim cmd As OleDbCommand
Dim dr As OleDbDataReader
Dim icount As Integer
Dim str As String

Private Sub btnAdd_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnAdd.Click
Try
cn = New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\PCBank.mdb;")
cn.Open()
str = "insert into customer values(" & CInt(tbID.Text) & ",'" & tbSur.Text & "','" &
tbFor.Text & "')"
'string stores the command and CInt is used to convert number to string
cmd = New OleDbCommand(str, cn)
icount = cmd.ExecuteNonQuery
MessageBox.Show(icount)
'displays number of records inserted
Catch
End Try
cn.Close()
End Sub

End Class

can anybody enliten me?

Re: adding to access database

DaveRRR13-Mar-07 9:18

DaveRRR

13-Mar-07 9:18

I might have the answer you seek, but I haven't looked in any depth at this problem.

It may be something to do with the insert statement and/or the customer table. Does the table only have 3 columns: an id, a surname and a forename? Is the id column auto-generated (or whatever the term is in MS Access)? Try naming the columns in your insert statement. I don't know what columns your customer table has but it might be something like this:

insert into customer (id, surname, forename) values (99, 'Rogers', 'Dave')

Dave

How can I call properties a run time created button?

JUNEYT13-Mar-07 6:20

JUNEYT

13-Mar-07 6:20

Hello!

It is quite bit intrique because I am creating 80 buttons in runtime and assigning a name with an incremental value such as myButton.Name = "GButton_" + I.toString. Therefore, each button has a different name.

Dim I as Int32
    For I = 1 to 5
        Dim myButton as New Button
            myButton.Name = "GButton_" + I.toString
            me.controls.add(myButton)
    Next

How can I reach the GButton_3.backcolor property somewhere in code (out of the procedure where I create the buttons). Would it be possible to define the name and set its property? Is there a way to use such as EVAL function to perform something eval( "GButton_" + I.tostring + ".backcolor=" + setcolor) THANK YOU. D'Oh! | :doh:

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

Re: How can I call properties a run time created button?

Guffa13-Mar-07 7:37

Guffa

13-Mar-07 7:37

Why throw away the reference to the button that you actually have, and then try to get it again?

Just store the references in an array so that you easily can access the buttons later.

---
single minded; short sighted; long gone;

Re: How can I call properties a run time created button?

testy_proconsul13-Mar-07 7:40

testy_proconsul

13-Mar-07 7:40

hi,

it is easier as you think

either you iterate the "Controls" collection of the Form:

For Each ctl as Control In Me.Controls
If ctl.Name = "GButton2" Then
ctl.Backcolor ....
Exit For
End If
Next

or you just call the following:

Me.Controls("GButton2").Basckcolor ...

storing it in an array is not necessary, because the added controls are already stored in an collection (Me.Controls)

solidIT.de - under construction
Components for Microsoft .Net
audittrail, objectcomparer, deepcopy and much more ...

Re: How can I call properties a run time created button?

JUNEYT13-Mar-07 7:53

JUNEYT

13-Mar-07 7:53

Thank you! I will try it... Cool | :cool:

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

Re: How can I call properties a run time created button?

Guffa13-Mar-07 10:08

Guffa

13-Mar-07 10:08

testy_proconsul wrote:
it is easier as you think

It's even easier than you think. Wink | ;)

testy_proconsul wrote:
storing it in an array is not necessary, because the added controls are already stored in an collection (Me.Controls)

Yes, of course it's not necessary, but it's the easiest and fastest way to get the reference.

---
single minded; short sighted; long gone;

Re: How can I call properties a run time created button?

testy_proconsul13-Mar-07 13:00

testy_proconsul

13-Mar-07 13:00

"i dont wanted to cut you short" ... guffa. and sorry for my bad english Smile | :)

but opinion is to keep the overhead as small as possible and to use predefined functionality. generally this keeps overview, readability and conformity ...

solidIT.de - under construction
Components for Microsoft .Net
audittrail, objectcomparer, deepcopy and much more ...

Printing a form's text fields

Central_IT13-Mar-07 5:50

Central_IT

13-Mar-07 5:50

Can anyone help me or point me in the right direction.

I am running VB.Net 2003 and have a form that I wish to print. For argument's sake, the form has 4 fields e.g. txtField1.text, txtField2.text, txtField3.text and txtField4.text

Each field has a value in it. How can I print this form or fields direct to my printer. The reason I want to do it this way is that each field has a complex calcualation to get to its value. Another way is how could I make a text file with these values and put onto a crystal report.

I hope this make sense.

Re: Printing a form's text fields

Duncan Edwards Jones13-Mar-07 7:44

Duncan Edwards Jones

13-Mar-07 7:44

You might be able to use this control[^], although it is written in VB.Net 2005 so you may have to do some changes...?

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

How can I detect which button is clicked on the form?

JUNEYT13-Mar-07 5:02

JUNEYT

13-Mar-07 5:02

Hello!

In shown sample below, I have a loop what ceates instances of a button. What I want to know is which one gets clicked in runtime? Thank you.

<code>
Public Sub AddButtons()

For I = 1 to 10
    Dim myButton as new Button
        myButton.text = "Hello"
        me.Controls.Add(myButton)

        AddHandler myButton.click, AddressOf myButtonEvent
Next

End Sub

' Here is the event handler for the button
Private sub myButtonEvent (Byval Sender as Object, e as EventArg)
    
     'Here I want to know which button has been clicked because there are 10 
     'buttons on the form.

End Sub
</code>

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

Re: How can I detect which button is clicked on the form? [modified]

M-Hall13-Mar-07 5:28

M-Hall

13-Mar-07 5:28

in your button event:

dim b as Button<br />
b= Ctype(sender,Button)

the b will be the button that was clicked.
If you are wanting to run different code depending on what button was clicked you can check for the name, or assign a value to the tag property and use that for identification.

Hope that helps Smile | :)

-- modified at 11:34 Tuesday 13th March, 2007

Re: How can I detect which button is clicked on the form?

JUNEYT13-Mar-07 5:34

JUNEYT

13-Mar-07 5:34

Yep! it is working now. Thank you very much. Cool | :cool:

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

Re: How can I detect which button is clicked on the form?

kubben13-Mar-07 5:34

kubben

13-Mar-07 5:34

You would want to set the button id value.
Something like myButton.Id = "btn"+I.ToString();

Then in the event
CType(Sender, Button).Id to figure out which button.

Hope that helps.
Ben

Re: How can I detect which button is clicked on the form?

testy_proconsul13-Mar-07 7:48

testy_proconsul

13-Mar-07 7:48

Private Sub AddButtons

Dim btn As Button

For i As Integer = 1 To 10
btn = New Button()
btn.Name = "GBtn" & i.ToString()
btn.Text = "Push " & i.ToString()
btn.Top = btn.Height * i
AddHandler btn.Click, AddressOf GBtn_Click
Me.Controls.Add(btn)
Next

End Sub

Private Sub GBtn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs)

MessageBox.Show(sender.ToString())

Select Case DirectCast(sender, Button).Name
Case "GBtn1"
Case "GBtn2"
End Select

End Sub

solidIT.de - under construction
Components for Microsoft .Net
audittrail, objectcomparer, deepcopy and much more ...

towers of hanoi

nyakallo13-Mar-07 4:58

nyakallo

13-Mar-07 4:58

help me with the towers of hanoi program.use recursive tower method. the parameters are 1.number of disks tobe moved
2.disks on initial peg
3.peg to which this stack of disks is tobe moved
4. peg tobeused as a temporary holding area

Re: towers of hanoi

Marcus J. Smith13-Mar-07 6:01

Marcus J. Smith

13-Mar-07 6:01

There is an article about this here [^] on Code Project. Do a search before asking for homework help.

DO YOUR OWN HOMEWORK

leckey14-Mar-07 9:04

leckey

14-Mar-07 9:04

You have three questions posted and they are all obviously homework. Work on it and if you get stuck then ask your question.

_________________________________________
You can't fix stupid, but you can medicate crazy.

Re: DO YOUR OWN HOMEWORK

Marcus J. Smith14-Mar-07 9:47

Marcus J. Smith

14-Mar-07 9:47

Wow I give him a link from CP and he reposts 2 days later. *Throws hands up in despair*

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