Re: Working with thread - Visual Basic Discussion Boards

KaptinKrunch3-Dec-05 5:00

3-Dec-05 5:00

Set that up in your folder options under file types. For the txt file type set your program to open instead of notepad or whatever.

Problem in datagrid

tusar1232-Dec-05 19:28

tusar123

2-Dec-05 19:28

Dear all
I am New to Vb.net
i want to add item in database , by entring data in datagrid.Grid should show one row at startup and when I press Another Key Like down Arrow , Then New Row must be Shown to insert the item .

please suggest me how it can be do.
Can VB.net support another third party grid.

Thanks in Advance

Tusar

Re: Problem in datagrid

KaptinKrunch2-Dec-05 20:06

KaptinKrunch

2-Dec-05 20:06

Fill your dataset, create a dataview based on row number in dataset, bind dataview to datagrid. In KeyUp event, +/- row selection.

Creation/editing of a test plan in Excel

ernest_krom2-Dec-05 14:27

ernest_krom

2-Dec-05 14:27

Hi gurus

I have a newbie question

I have a test plan for the mechanical device, which look a bit like

1. measure this voltage
2. write down the color of the wire
2.1 ....
2.2 ....
3. etc

I would like to create the front end, which would diplay the plan from the excel spreadsheet and allow technician to respond to the items of the plan. Sometimes technician must put the yes/no answer and sometimes put the comment as a result of the test.

I don't want to invent bisycle and assume somebody already done this. Could you point me to the good article/book or ready made program for fulfilling such task?

I put the question into VB forum, because my research up to now shows that such ready-made-program doesn't exist and I will need to write one.

Shura

How to ditribute xml files with dll

Fawxes2-Dec-05 13:00

Fawxes

2-Dec-05 13:00

I'm writing a class project in visual studio 2003.

Part of the data used by the classes is stored in xml files that the user will be able to edit.

The classes are used by other applications and an end user could have more than one of these applications on their machine.

How do I distribute the classes so that they know where to find the xml data files every time and they are only saved once.

I had originally used the Application.StartupPath to find the folder where the class dll file is stored but, when I create another application the value returned by Application.StartupPath doesn't return the folder where the xml data files are stored it returns (quite rightly) the folder of the original application.

Any idea on how I go about distributing and accessing these xml files?

Any help would be gratefully received as this is a project I intend to open up on a 'do-what-you-want' licence without copyright and for all to use.

Thanks in advance

An optimist's glass is half full.
A pesimist's glass is half empty.
An engineer goes and gets the right size glass.

Working with thread

VanitaJ2-Dec-05 12:00

VanitaJ

2-Dec-05 12:00

Hi All
Its a very simple code.
Project has 3 forms. On load of the first form say Form1 I am creating a new thread. Under this thread I am intitializing the timers of Form2. And then show a different form say Form3 using showdialog

but I am not able to understand why doent the timer event of the timers present on Form2 gets called inspite of being intialized under the start of the thread.

Please help me to find the reason why doesnt this code work

See the code below

Public Class Form1<br />
    Inherits System.Windows.Forms.Form<br />
Public NewThread As System.Threading.Thread<br />
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load<br />
        NewThread = New Threading.Thread(AddressOf StartNewThread)<br />
        NewThread.Start()<br />
<br />
        Dim objFrm As New Form3<br />
        objFrm.ShowDialog()<br />
    End Sub<br />
    Private Sub StartNewThread()<br />
        Dim obj As New Form2<br />
        While True<br />
            If (obj.Timer1.Enabled = False) Then<br />
                obj.Timer1.Start()<br />
            End If<br />
            If (obj.Timer2.Enabled = False) Then<br />
                obj.Timer2.Start()<br />
            End If<br />
        End While<br />
    End Sub<br />
End Class<br />
<br />
<br />
Public Class Form2<br />
    Inherits System.Windows.Forms.Form<br />
  Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer1.Tick<br />
        MsgBox("Inside timer event of timer1")<br />
    End Sub<br />
<br />
    Private Sub Timer2_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer2.Tick<br />
        MsgBox("inside timer event of TIMER2")<br />
    End Sub<br />
End Class<br />
<br />
<br />
Public Class Form3<br />
    Inherits System.Windows.Forms.Form<br />
Private Sub Form3_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load<br />
        Application.DoEvents()<br />
    End Sub<br />
End Class

Thanks,
~VanitaJ

Re: Working with thread

Dave Kreskowiak2-Dec-05 14:13

Dave Kreskowiak

2-Dec-05 14:13

Well, I've never put Form's-based Timers in other threads. In theory, though, they're not working because the Timer Tick events are not getting to the forms because those forms are on seperate threads from the main UI thread of your application.

In the example code you've posted, there is no need for seperate threads at all. You shouldn't be putting different forms on seperate threads. All your forms go on the UI thread, while background work goes into seperate threads and uses Invoke method calls back to their parent forms to have the forms update themselves with new data.

RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome

Re: Working with thread

VanitaJ3-Dec-05 9:22

VanitaJ

3-Dec-05 9:22

Thanks Dave.
I have to achieve something similar. Hence trying out a small example with 3 forms.

~VanitaJ

Set Focus on a TextBox in a DataGrid

dptalt2-Dec-05 10:07

dptalt

2-Dec-05 10:07

How can I set focus on a TextBox in a given row in a DataGrid?
Thanks

-- modified at 8:51 Monday 5th December, 2005

Or How can I change the Tabstop propery to false on certain column in a Datagrid?

I've tried this but it does not work.

grdColumnStyle2.TextBox.TabStop = False

acces serial port

Jodd2-Dec-05 9:53

Jodd

2-Dec-05 9:53

I want to use the serial port to flash a led. Is there a simple way to acces the serial port.
Al I want is a snippet that can put a signal on the serial port where the led is connected

Re: acces serial port

Dave Kreskowiak2-Dec-05 10:43

Dave Kreskowiak

2-Dec-05 10:43

The serial port is a poor choice to do this because you would have to constantly raise a signal to keep the LED lite. The parallel port is a much better choice and there are plenty of examples on how to do it.

Also, there is no "easy" way to do this. Low-level hardware control is beyond the ability of VB.NET or C# code alone. You need a .DLL that runs inside Ring 0 (device drivers) to handle the hardware for you.

You can find a pretty good example of parallel port control at http://www.logix4u.net. For more than that, just Google for "VB parallel LED".

RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome

Re: acces serial port

Jodd2-Dec-05 13:37

Jodd

2-Dec-05 13:37

Thanks, but ...

The parallel port is already in use.
The only thing i have to do is after pressing a button on the screen send a single pulse to the serial port for opening a lock. I have a opto coupler for saftey, so a single flash from the led is all it takes.

Re: acces serial port

Dave Kreskowiak2-Dec-05 13:55

Dave Kreskowiak

2-Dec-05 13:55

The problem with that is the pulse comming from the serial port usually isn't long enough to allow an LED to completely illuminate.

You can TRY this (lifted from Experts Exchange):

MSComm1.CommPort = 1                       'select your com port either 1 or 2 or 3 if you have it
    MSComm1.Settings = "9600,n,8,1"             'this must be configured to your specifications
                                                '9600 is the baud rate, n is no parity bits, 8 data bits and 1 stop bit
    MSComm1.PortOpen = True                     'opens the port
End Sub
 
'To send data from the com port
Private Sub cmdSend_Click()
    MSComm1.Output = "111111111111111"
End Sub

It uses the old MSCOMM control from the VB6 days. There's virtually no examples of doing this, because of the problems with using the serial port to do anything useful with an LED.

RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome

Re: acces serial port

Jodd2-Dec-05 15:02

Jodd

2-Dec-05 15:02

I will try it

Thanks

Re: acces serial port

Fu Manchu3-Dec-05 14:21

Fu Manchu

3-Dec-05 14:21

You could use a microcontroller and send data via the rs232 port! Big Grin | :-D

I don’t know your electronics abilities, but a simple PIC16F84 or PIC16F628 would be suitable, you can even use BASIC to program the PIC. Just create a basic selection program and control it via VB.NET.

Trust me there are thousands of examples on the net! Smile | :)

change the caller form based on the result of the called form

hui20062-Dec-05 7:52

hui2006

2-Dec-05 7:52

Hello,
I am coding a text editor program. I creat my main form with a menu. While the user hit a menu item, a different form would come out and ask for input. After that, I would like the change reflected in the main form, say, TextBox1 in the main form.
Can somebody give suggestions?

Best,
Hui

Re: change the caller form based on the result of the called form

Briga2-Dec-05 7:55

Briga

2-Dec-05 7:55

Different way of accomplishing it.

Common one, and easiest, is:

sub form1clickwhattever....
form2.show
me.textbox1.text = form2.controlwithdata.text
end sub

Re: change the caller form based on the result of the called form

hui20066-Dec-05 0:58

hui2006

6-Dec-05 0:58

Thanks for the reply. I tried to use the code in my program. However, it does not work. I would like the me.textbox1.text get changed after the user click on an OK button in the 2nd form. The code above replaces the textbox1.text with a blank string, since the user has not filled out the info yet. I guess that I need to refer to the caller (main form) in the called form (child form), but I don't know how to refer to the main form in the child form. In Visual Basic 6, I think I can just call its name but not in Visual Basic .Net. Any suggestions?

Re: change the caller form based on the result of the called form

Briga6-Dec-05 4:06

Briga

6-Dec-05 4:06

Well my code has an error or better it was missing the form2.showdialog (so that the next line is executed only after the form2 has been hidden/closed with the button).
So if you replace .show with .showdialog then it works.

Anyway if you want a more precise answer you should provide more precise informations. Which versione of FW are you using 1.x or 2? VS2003 or VS2005.

In VS2003 you can refer to the calling form only if it's public declared.

Module x
public fmain as new frmMain
end module

then in the form2 button click event handler:
fmain.textbox1.text = ....

In VS2005 in most cases you can state immediatly the form without instancing it. This means you can have a direct access to frmMain (considering the previous example) unless you're running an instance created by you (than you fallback in the former case).

Another way of doing it is by raising an event.

In form2 you'll have:

...
raisevevent OKClicked()

and in form1

private sub ClickOnForm2() handles frm2.OKClicked
me.textbox1.text = frm2.textbox1.text
end sub

or using parameters ...

public class frm2eventargs
inherits eventargs
public t as string
end class

on form2 before you raise the event...

dim e as new frm2eventargs
e.t = (text to pass)
raiseevent OKClicked(me,e)

and then on the mainform

private sub frm2OKClick(sender as object,e as frm2eventargs) handles frm2.OKClicked
me.textbox1.text = t
end sub

So as you can see lot of options depending on the approach you want and what you're using.

VB.Net Controls: TypeConverter

vocaris2-Dec-05 5:18

vocaris

2-Dec-05 5:18

At a other site on the web (http://www.codeguru.com/columns/VB/article.php/c6529[^]) I found a sample for TypeConverters. I played a little with this sample: I added a new class 'TestControl' (Inherited from UserControl) with one userdefinded-Property 'TestProperty As Circle'. If I add my TestControl to a Form, the IDE generates the following Code:
Me.TestControl1.TestProperty = CType(resources.GetObject("TestControl1.TestProperty"), tester.Circle)

And now there comes my problem: I want that the TestProperty becomes a ReadOnly-Property and die generated Code has to look like this:

Me.TestControl1.TestProperty.X = 4<br />
Me.TestControl1.TestProperty.Y = 5<br />
Me.TestControl1.TestProperty.Radius = 3

Is this posible or want I too much?

Re: VB.Net Controls: TypeConverter

[Marc]2-Dec-05 6:21

[Marc]

2-Dec-05 6:21

Just doing a wild guess here:

In your converter:

Public Class CircleConverter
  // This makes the object expandable in the property grid.
  Inherits ExpandableObjectConverter

And for your property:

// This makes that the properties of the circle are in the generated code. 
<DesignerSerializationVisibility(DesignerSerializationVisibility.Content)> _
Public (ReadOnly?) TestProperty As Circle ...

Maybe you can put the DesignerSerializationVisibility attribute for the Circle structure instead for each property, but i don't know that (maybe you should try it out Wink | ;)

).
DesignerSerializationVisibility and ExpandableObjectConverter are in the System.ComponentModel namespace, so maybe you have to import that or something.

HTH Smile | :)

Pompiedompiedom... Wink | ;)

"..Commit yourself to quality from day one..it's better to do nothing at all than to do something badly.."
-- Mark McCormick

Thank you

vocaris2-Dec-05 7:50

vocaris

2-Dec-05 7:50

The second time you helped me much. Thanks

Re: Thank you

[Marc]2-Dec-05 10:06

[Marc]

2-Dec-05 10:06

Your welcome (for both times of course Poke tongue | ;-P

)!

Pompiedompiedom... Wink | ;)

"..Commit yourself to quality from day one..it's better to do nothing at all than to do something badly.."
-- Mark McCormick

Counting Records..........

daviiie2-Dec-05 5:14

daviiie

2-Dec-05 5:14

Is there simple way to find out how many records there are in a database table? Access database table that is.

Re: Counting Records..........

vocaris2-Dec-05 5:21

vocaris

2-Dec-05 5:21

The only way with Access I knowing is the following SQL-Statement:
SELECT COUNT(*) AS TableCount FROM [Table]

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