Re: About InvalidOperationEception - C# Discussion Boards

jacklynn_mei18-Nov-07 22:56

jacklynn_mei

18-Nov-07 22:56

Dude..have done like the code below but the data cannot display for 10secs.

public load(....)
{
Timer myTimer = new Timer();
myTimer.Interval = 10000;
myTimer.Enabled = true;
myTimer.Tick += new EventHandler(Timer_Tick);
}

public void Timer_Tick(object sender, EventArgs e)
{
string conStrg;
conStrg = ("Data Source=DIMENSION3000\\SQLEXPRESS;Initial Catalog=kMasjid;User ID=sa;password=123456");
SqlConnection connTimer = new SqlConnection(conStrg);
connTimer.Open();
string selSQL = "Select txtDesc FROM txtScroll";
SqlCommand com = new SqlCommand(selSQL, connTimer);
SqlDataReader reader = com.ExecuteReader();
DataSet ds = new DataSet();

while (reader.Read())
{
alphaTxtMain.Text = " " + reader["txtDesc"];
myTimer.Interval = 10000;
myTimer.Stop();
}

sindhutiwari18-Nov-07 23:00

sindhutiwari

18-Nov-07 23:00

i dint get u...data is not at all displayed or its blinking...?

its me sid

jacklynn_mei19-Nov-07 14:21

jacklynn_mei

19-Nov-07 14:21

Mmm..it's like blinking.
Supposed that, the output is 10secs for each data to be displayed.

About InvalidOperationEception

KennyPatel19-Nov-07 0:22

KennyPatel

19-Nov-07 0:22

Hi.

You can use above meta tag which refresh every 5 seconds your page. U can use it in also.

I hope can help this.
Thanks
Laugh | :laugh:

<div class="ForumSig">"Good Thing Goes With Good People..."</div>

jason_mf18-Nov-07 21:05

jason_mf

18-Nov-07 21:05

I have a WindowsForm project.
When I open a dialogForm from my MainForm, do nothing.
Then I close this dialog.

This time VS2005 report "InvalidOperationEception: Invoke or BeginInvoke cannot be called on a control until the window handle has been created." at "Application.Run(new MainForm());"

what cause can beget this exception?

Re: About InvalidOperationEception

JoeRip18-Nov-07 21:39

JoeRip

18-Nov-07 21:39

Can we see the code?

Are you calling Invoke or BeginInvoke directly?

Re: About InvalidOperationEception [modified]

jason_mf18-Nov-07 22:16

jason_mf

18-Nov-07 22:16

My code:

#region Open dialog part<br />
private void btnSetting_Click(object sender, EventArgs e)<br />
{<br />
   OpenSettingForm();<br />
}<br />
<br />
private void OpenSettingForm()<br />
{<br />
   FormSetting frmSetting = new FormSetting(this.localUIN.ToString(),      this.localInfo.NickName, this.localInfo.Sign, ServiceURL,  this.pictureBox1.Image, this.tabControl1.Tabs, this);<br />
<br />
   frmSetting.Width = 535;<br />
   frmSetting.Height = 505;<br />
   frmSetting.Owner = this;<br />
   frmSetting.ShowDialog();<br />
}<br />
#endregion<br />
<br />
#region close dialog part<br />
//save new settings<br />
private void ApplySettings()<br />
{<br />
    int myuin = Convert.ToInt32(uin.Substring(1));<br />
<br />
    if (!string.Empty.Equals(this.txtNick.Text.Trim()) && !this.oldNick.Equals(this.txtNick.Text.Trim()))<br />
    {<br />
        if (this.callService.UpdateNick(myuin, this.txtNick.Text) > 0) <br />
        {<br />
            FreeAssemblage.SetSettings(this.uin, "Nick", this.txtNick.Text.Trim());<br />
         }<br />
     }<br />
<br />
     if (!this.oldSign.Equals(this.txtSign.Text))<br />
                this.callService.UpdateSign(myuin, this.txtSign.Text);<br />
<br />
     FreeAssemblage.SetSettings(this.uin, this.hashConfig);<br />
<br />
     this.frmMain.OperateHistory(this.chkHistory.Checked);<br />
}<br />
<br />
private void btnApp_Click(object sender, EventArgs e)<br />
{<br />
ApplySettings();<br />
<br />
this.btnApp.Enabled = false;<br />
}<br />
<br />
//close setting dialog<br />
 private void btnOK_Click(object sender, EventArgs e)<br />
{<br />
   if (true == this.btnApp.Enabled)<br />
   {<br />
     ApplySettings();<br />
   }<br />
<br />
    this.Close();<br />
<br />
}<br />
#endregion

-- modified at 4:23 Monday 19th November, 2007

Re: About InvalidOperationEception

JoeRip18-Nov-07 22:45

JoeRip

18-Nov-07 22:45

I suspect your exception isn't caused by this section of code.

Is there a chance that code in your main form is referencing a control on the form that just closed, or calling a method that does?

I don't know how useful it is, but:

You are getting this Exception all the way up at Application.Run because it is unhandled all the way up. Take a look at the StackTrace and see where it's originating. Look at the Exception.InnerException (if there is one) to see if you can tell where things are happening.

Try putting an Exception Handler for this Exception lower in your code, closer to where you think this is occuring. Another thing to try is putting a check for "this.InvokeRequired" in your event handlers - you can get the InvalidOperationException if you have threads accessing controls from other threads, and this will tell you if that is happening.

Look at Invoke and BeginInvoke in MSDN, and take a look at InvalidOperationException there also. Sorry I can't be of more help.

question concerning windows service

stephan_00718-Nov-07 21:05

stephan_007

18-Nov-07 21:05

hi everyone!

i did a console application, which reads from a file, parses the information, changes the contence and then writes the result to another file. at the moment, the application has to be started by hand. that's why i want to change it to a service, which checks a directory for files of a special kind and then does it's operation.

is there anything special i have to look for when changing from console application to windows service. is there some kind of template i could use to easily convert it?

and besides, do you have a good idea how to check if a file has already been operated? i do have two ideas concerning this situation. number one is to delete the source afterwards and the second one would be to remember the date/time of the last file (meaning the youngest one) and to be searching for newer ones. the first idea sounds a little easier, because in this case i do only have to read the directory contence whereas in the second idea i have to read the contence and remove all files, which are already parsed.

thanks for any further ideas or hints.
stephan.

Re: question concerning windows service [modified]

Jimmanuel19-Nov-07 2:07

Jimmanuel

19-Nov-07 2:07

To create a Service[^]

For the second thing how about using a FileSystemWatcher[^]? It has some events which might take care of your problem.

Last modified: 57mins after originally posted -- grammatical typo

Re: question concerning windows service

PIEBALDconsult19-Nov-07 4:32

PIEBALDconsult

19-Nov-07 4:32

You could also add it as a Scheduled Task.

As to keeping track of what it had already processed, I usually store such information in a database, but with such a simple program, a config file should be sufficient.

Changing Column Balue Before Insert in Data Grid

Aftab Sindhi18-Nov-07 20:55

Aftab Sindhi

18-Nov-07 20:55

I've typed data set and Binding source in the windows form. Data Grid is bound to the Binding Source. Table's primary key is Uniqueidentifier / Guid, which is hidden in DataGrid. Row contains some other NOT NULL columns, i.e Name. I can insert the record by generating the NewGuid() in DataGrid's RowValidating event and assigning to the Primary key field. Its working fine. Problem is this, when DataGrid's New Row is clicked(to add new row), and without typing any value(i.e Name) record pointer is changed (any other row is clicked), error is generated reporting that [Name] can not be null i.e Null value can not b inserted in NOT NULL column Name. I am sure RowValidating is fired, which has populated the ID with new generated Guid value, but Name is not entered thats why error is thrown.

How I can detect row is not entered so that I should not assign new Guid value to ID or How & where I can assign the new generated Guid, when it is sure the row is entered?.

Hope i can get quick response including sample code if possible.

Regards

Graphical Grid in c#.net

sindhutiwari18-Nov-07 20:47

sindhutiwari

18-Nov-07 20:47

Hi,
I want to show a graphical grid in the windows form..its for alingnments of labels....n etc. ......if anyone knows how to do this please do let me know...............................
regards
sindhu tiwari

Always Innovative

How to refresh child picturebox when moving (with mouse) on parent picturebox.

Chintan.Desai18-Nov-07 20:13

Chintan.Desai

18-Nov-07 20:13

HI guys,
I have resize picturebox (say picMain) to the size of form.There are many picturebox inside picMain. Now I am moving child picturebox ( on mouse_move event) on picMain. I am getting refresh problem while dragging child picturebox. I had use Refresh(),Update() and Invalidate()method of child picturebox but not getting precise solution. It seems like child picturebox ghost is following it.
Instead of picMain if I work with main form then it work very well. I think picturebox has less ability to refresh faster compare
to form (am I write??).
I want same effect as what we dragged item from visual studio toolbox and move around in the form.

pls give the solution Confused | :confused:

thanks in advance.

Regards
Chintan
www.visharadsoft.com
(I am thinking to change humans to computer, but unfortunately GOD will not give me the source code)

Barcode reader events handillinh

shahid hameed18-Nov-07 20:04

shahid hameed

18-Nov-07 20:04

i am using a usb barcode reader which install as "human interface device" and vender dostn provide any sdk with it.
i want to handill its event of barcode reading
can any one guide me

Re: Barcode reader events handillinh

MickCurley18-Nov-07 22:47

MickCurley

18-Nov-07 22:47

No SDK?
Then as HID you need to add a Key Press EventHandler
and decide what the data is. I presume its a Winform?

If the scanner comes with a configuration utility that allows
it to be set as "Serial Emulation Device" then you can use a
SerialDataReceived EventHandler which is easier... Smile | :)

Regards
Michael Curley

A craft is an enemy if not well learned.

String Manipulation

Programm3r18-Nov-07 20:02

18-Nov-07 20:02

Hi all,

I have the following string:

drwxr-xr-x 1 ftp ftp	0 Nov 09 07:04 Windows
drwxr-xr-x 1 ftp ftp	0 Oct 29 2007 Nvidia
drwxr-xr-x 1 ftp ftp	0 Jan 01 2003 Program Files

I would like to extract only the folder name i.e. "Windows" or "Program Files", but my string manipulation isn't so good in C# can anyone please help me?

Many Thanks
Regards,

The only programmers that are better that C programmers are those who code in 1's and 0's Green Alien | [Alien]

Programm3r
My Blog: ^_^

Guffa18-Nov-07 20:58

Guffa

18-Nov-07 20:58

The string looks broken, doesn't all the entries have both a year and a time?

If they do, the number of characters before the folder name should be constant, and you can just split the string on Environment.NewLine and use .Substring(41) to get each folder name.

Experience is the sum of all the mistakes you have done.

Programm3r18-Nov-07 21:12

18-Nov-07 21:12

Hi Guffa,

Thanks for the response. I don't think the string is broken, as I stated in my previous post, that's how the FTP server (FileZilla) returns the directory list, but I'm on the verge of figuring it out Smile | :)

Thanks
Regards,

The only programmers that are better that C programmers are those who code in 1's and 0's Green Alien | [Alien]

Programm3r
My Blog: ^_^

Guffa19-Nov-07 0:16

Guffa

19-Nov-07 0:16

Ok, is that the only variations there are, or are the items that are listed with both year and time, and items that are listed without both?

Experience is the sum of all the mistakes you have done.

Programm3r19-Nov-07 0:41

19-Nov-07 0:41

Guffa wrote:
is that the only variations there are, or are the items that are listed with both year and time, and items that are listed without both?

Yes that is the only variants there are.

The only programmers that are better that C programmers are those who code in 1's and 0's Green Alien | [Alien]

Programm3r
My Blog: ^_^

mabo4219-Nov-07 0:53

mabo42

19-Nov-07 0:53

Guffa, this is the way the most ?nixe show their directory entries. For older entries they show date without time, for younger date without year, but with time. But in all cases you can't rely on fixed width column structure.

Regards

Programm3r19-Nov-07 0:56

19-Nov-07 0:56

mabo42 wrote:
But in all cases you can't rely on fixed width column structure.

So what can one rely on ...

The only programmers that are better that C programmers are those who code in 1's and 0's Green Alien | [Alien]

Programm3r
My Blog: ^_^

mabo4219-Nov-07 1:09

mabo42

19-Nov-07 1:09

The columns you showed are always exist, but the width can differ in width (perhaps not in your case, username is always ftp, directory size is always 0...). To be on the safe side, use RegEx.

Regards