Re: Need VSD for asp.net case study - C# Discussion Boards

Re: How to safely Form.Invoke from another thread?

Luc Pattyn25-Jul-07 7:29

25-Jul-07 7:29

are you kidding ?

the Dispose() method is the one that typically will be executed by the finalizer thread.
Do you think it will appreciate your lock ?
if the finalizer cant do its job, the GC has less memory to manage and recycle;
do you want the GC to run out of memory for no good reason ?

I am not sure what the right answer is, but what you propose seems very wrong to me. Confused | :confused:

Luc Pattyn

try { [Search CP Articles] [Search CP Forums] [Forum Guidelines] [My Articles] }
catch { [Google] }

Re: How to safely Form.Invoke from another thread?

michal.kreslik25-Jul-07 11:41

michal.kreslik

25-Jul-07 11:41

Actually, it does not appreciate my lock Smile | :)

If I'm forcing the Dispose() to wait on the lock until all Invokes are done and until I make sure there are no Invokes going to be done in the future, I'm effectively blocking that form's Window Message Queue.

If I'm blocking the Window Message Queue, the Invoke never returns.

Obviously, the same happens (WMQ block => Invoke never returns) if I try, for instance, to block after Form.Closing event etc.

So I'm back at the beginning Smile | :)

Any suggestions? Smile | :)

Thanks,
Michal

Re: How to safely Form.Invoke from another thread?

Luc Pattyn25-Jul-07 12:15

Luc Pattyn

25-Jul-07 12:15

I'm sure I would have some suggestions (or at least comments) if I felt I understood
your problem. You seem to somehow Dispose() of a form, while you may still need it.

So I need more info (contextual I guess).

For what it's worth: I typically dont dispose of forms, I just close them.
I realize you may want to avoid Close() so you can play with Hide() and Show() again,
but even then the last time you could Close() rather than Dispose(), couldnt you ?

Smile | :)

Luc Pattyn

try { [Search CP Articles] [Search CP Forums] [Forum Guidelines] [My Articles] }
catch { [Google] }

Re: How to safely Form.Invoke from another thread?

michal.kreslik25-Jul-07 21:43

michal.kreslik

25-Jul-07 21:43

Hi, Luc,

thanks for your comment. I'm not disposing of the form myself. I'm just closing it. But the whole point is in not allowing the form to get disposed before all possible Invokes on it are done.

I can briefly outline what is going on in my app: a server application is calling my client app every 100 ms via COM and refreshes its state. Sometimes it happens that the server stops calling my client app and I need to detect that.

For that purpose I've written a simple timer class that's started together with the app. The core class of my app stores the timestamp of the last COM call and my timer class checks every 200 ms whether the difference between DateTime.Now() and last COM call timestamp is higher than maximum allowed. If it is, it Invokes a method on a form that's telling me the connection has been lost. If it's not, it Invokes a method on a form that's telling me the connection is OK.

Obviously, the timer runs on a separate thread from the form's thread. When I'm closing the form (which does not close the application itself), I need to make sure that the timer executes the last Invoke on the form and shuts itself off.

And there's the problem. In order to make sure that the timer executes the last Invoke on the form safely, I need to prevent the form from disposing of itself before that last Invoke is done. But if I'm preventing the form from disposing of itself by putting a lock anywhere between the moment when the form starts closing and the moment when it starts getting disposed of, I'm effectively blocking the window message queue, so the last Invoke (which is executed while the form waits on a lock) never returns.

Thanks much for any help.

Michal

Re: How to safely Form.Invoke from another thread?

michal.kreslik25-Jul-07 23:13

michal.kreslik

25-Jul-07 23:13

OK, so I resolved the issue. It's certainly not the most elegant solution, but it works. I will still appreciate if someone tells me how this should be done "professionally" Smile | :)

Instead of a lock, I'm using an ordinary while loop. The while loop has an advantage over lock of being able to execute something while it's waiting for a signal. Lock simply sits there and does nothing until the lock is released.

So I placed the while loop inside the Form.Closing() event handler. This while loop is blocking the form from closing itself (and thus disposing of itself). Inside this loop (apart from waiting for a signal) I'm executing Application.DoEvents() every 50 ms. This ensures that the Invoke, waiting on the second thread, gets processed.

If you've got some better suggestion, please tell me.

Thanks,
Michal

GROUP BY RECORD IN GRIDVIEW & EXPORT TO EXCEL

krishanpanda25-Jul-07 1:07

krishanpanda

25-Jul-07 1:07

how to display group by data in gridview
and export it to excel.
example
GROUP1
CONTENT1-A CONTENT1-B
CONTENT1-A CONTENT1-B
GROUP2
CONTENT1-A CONTENT1-B
CONTENT1-A CONTENT1-B
AND EXPORT THE EXACT INTO EXCEL

kp_chat@yahoo.co.in

Need VSD for asp.net case study

Banjo Ayorinde25-Jul-07 1:05

Banjo Ayorinde

25-Jul-07 1:05

Am relatively new to asp.net and need a challenging case study. Pls send me a VSD to prepare myself for one of the best job around.

Thanks.

Re: Need VSD for asp.net case study

UglyxXXx25-Jul-07 23:25

UglyxXXx

25-Jul-07 23:25

Hei U buy by your self a**hole Roll eyes | :rolleyes:

DataGridView

sangramkp25-Jul-07 0:48

sangramkp

25-Jul-07 0:48

How to iterate through every cell of a datagridview?

Re: DataGridView

Tormod Fjeldskaar25-Jul-07 1:00

Tormod Fjeldskaar

25-Jul-07 1:00

foreach(DataGridViewRow row in yourDataGridView.Rows)<br />
{<br />
  foreach(DataGridViewCell cell in row.Cells)<br />
  {<br />
    /* do your stuff */<br />
  }<br />
}

datagrid focus

praveenkumar palla25-Jul-07 0:45

praveenkumar palla

25-Jul-07 0:45

present functionality:
on load the datagridview's selection mode is "FullRowSelect".
on clicking "Rename" button i am changing the selection mode to "CellSelect"(only the column is editable) and selecting that cell of the selected row index and then double clicking on that cell we able type(cursor is focusing to that cell) the code is

dgvLasers.EditingPanel.Visible = true;
bEdit = true;
dgvLasers.SelectionMode = DataGridViewSelectionMode.CellSelect;
dgvLasers.Rows[intIndex].Cells[1].Selected = true;

but a small change required
on clicking "Rename" button only the cell shold be selected and cursor should be focused to that cell (i.e. without clicking on the cell we should able to type or replace the text)

please help me on this

Thanks in advance

praveen Kumar palla

Re: datagrid focus

Nouman Bhatti25-Jul-07 2:46

Nouman Bhatti

25-Jul-07 2:46

set
datagridview.readonly = false
datagridview.editmode = editonenter

then write your code

Hiding Form after loading another

Banjo Ayorinde25-Jul-07 0:12

Banjo Ayorinde

25-Jul-07 0:12

How do I hide a from from which 've just loaded another.

I load formB after meeting certain criteria and wish to close the formA from wish 've loaded formB

Re: Hiding Form after loading another

Eduard Keilholz25-Jul-07 0:21

Eduard Keilholz

25-Jul-07 0:21

form.Hide();

BTW, don't double-post...

.: I love it when a plan comes together :.
http://www.zonderpunt.nl

Re: Hiding Form after loading another

PhilDanger25-Jul-07 3:51

PhilDanger

25-Jul-07 3:51

Another idea would be to use the Main application program as a staging ground for each form.

//---code inside FormA ---
if(conditionMet){
    DialogResult = DialogResult.OK;
    this.Close();
}


//code inside Main

FormA formA = new FormA();
Application.Run(formA);
if(formA.DialogResult == DialogResult.OK){
     FormB formB = new FormB();
     Application.Run(formB);
}

Hiding Form after loading another

Banjo Ayorinde25-Jul-07 0:09

Banjo Ayorinde

25-Jul-07 0:09

How do I hide a from from which 've just loaded another.

I load formB after meeting certain criteria and wish to close the formAioud form from wish I load formB

Creating a web based report in win app

Banjo Ayorinde25-Jul-07 0:02

Banjo Ayorinde

25-Jul-07 0:02

I wish to create a report to be displayed in a browser offline in my windows application. I do not want to use crystal report.

How do I create a web based report through C#.Net 2005 version that can accept parameters without using crystal report

Or

How do I display parameters oriented values from SQL (database)on a browser offline

hoe to pass parameter in crystal report dynamically?

help as an alias25-Jul-07 0:00

help as an alias

25-Jul-07 0:00

i want to pass two sting parameters in crystal report to run the query
SELECT * FROM xyz WHERE abc BETWEEN 'parameter1' AND 'parameter2'

i want to write the code on form which have crystal report viewer but i have no idea, i also searched on internet but that was not helpfull. anybody can give me code that will work than i will be your thankful. Confused | :confused:

Nikesh Kr. Yadav

CSS Infotech
Sec- 31
Gurgaon,
Haryana(India)

Re: hoe to pass parameter in crystal report dynamically?

Nouman Bhatti25-Jul-07 2:54

Nouman Bhatti

25-Jul-07 2:54

try this link.

http://www.thescripts.com/forum/thread225413.html

Re: hoe to pass parameter in crystal report dynamically?

help as an alias25-Jul-07 3:00

help as an alias

25-Jul-07 3:00

thakx but i was the same answer on google.
but its really thankx for your reply
one more thing can you answer me

how to some the number in crystal report?

Nikesh Kr. Yadav

CSS Infotech
Sec- 31
Gurgaon,
Haryana(India)

mouse event

cyn824-Jul-07 23:56

cyn8

24-Jul-07 23:56

hi, i have a question. imagine i have a window form and in it i have a panel. now, i need to do a mousedown on the form and then mouseup in the panel. The idea here is to create a drag and drop action. However, the by creating those events, it does not seem to work because the mouseup event is never called although i click on the mouse on the form and then hold and finally release in the panel area.
What events should i use since this can''t work?

Thanks in advance.

Re: mouse event

Eduard Keilholz25-Jul-07 0:22

Eduard Keilholz

25-Jul-07 0:22

Why don't you just use the drag & drop functionality a form already supports.. It will save you a lot of headache!

.: I love it when a plan comes together :.
http://www.zonderpunt.nl

Re: mouse event

Martin#25-Jul-07 0:29

Martin#

25-Jul-07 0:29

Hello,

The trick is to handle the MouseUp from the form as well, and check if the Cursor is in the Panel range.

Point pt = yourPanel.PointToClient(Cursor.Position);
Rectangle rc = yourPanel.ClientRectangle;
if (rc.Contains(pt))
{	
    //It's in the panels range
}

Hope it helps!

All the best,

Martin

C# Screensaver

Identity Undisclosed24-Jul-07 23:52

Identity Undisclosed

24-Jul-07 23:52

Hi,

I am creating a developing screensaver in C#. I have done everything to create screensaver. Now I am stuck in a problem. How to create a scr file ? I have renamed the exe to scr. However, if I right click the scr file and select the install option, my antivirus prompts a suspicious activity. Any help on this ?

Thanks,

"C makes it easy to shoot yourself in the foot. C++ makes it
harder, but when you do, it blows away your whole leg."
- Bjarne Stroustrup

Re: C# Screensaver

Martin#24-Jul-07 23:57

Martin#

24-Jul-07 23:57

Identity Undisclosed wrote:
How to create a scr file ? I have renamed the exe to scr

That's it!

Identity Undisclosed wrote:
However, if I right click the scr file and select the install opti

You don't need to install it!
Just copy it in the "Windows" directory.

All the best,

Martin

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