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Re: Question For List Generics

Sider8914-Jun-09 19:39

14-Jun-09 19:39

Maybe it'll work, but in my project I have many classes and Functions with generics and it's almost impossible to change all Big Grin | :-D

Big Grin | :-D

I think I solve this like this, I write it:

public delegate List< T > LoadChildHandler< T >(int parentId);

public class ObjectBase< T >
{
public int ID { get; set; }
}

public class Country : ObjectBase< Country >
{

public LoadChildHandler< City > LoadChild; // I just declare delegate in child class and there are not resist between City and Country, well works fine

public string CountryName { get; set; }

public List< City > Cities
{
get
{
return LoadChild(ID);
}
}
}

and so all I want it to do in a different way...
Now I must dclare this delegate in other classes too, it would be fine to do solve this problem, without declaring in other classes and not such torture Smile | :)

Smile | :)

C# Developer

Closing and recreating a form

SimpleData13-Jun-09 22:43

13-Jun-09 22:43

Hi I have a Windows form called mainwindow in my project. After it completes what it does, it closes and then recreates itself. But as I have noticed lately it recreates but doesnt't close itself.

Here is my code:

private void RestartAll()
{
   // These are not that important, only to transfer the same properties of the form to the new form.
   depo.multipleformlocation=this.Location;
   depo.multipleform = true;
   depo.ekrangoruntusuadedi = 0;

   this.Hide();

   mainwindow _mainwindow = new mainwindow();
   _mainwindow.ShowDialog();

   this.Close();

   // Here is my temporary solution (putting old form's thread to sleep infinitely because it shouldn't keep doing what it does)
   Thread.Sleep(Timeout.Infinite);
}

How can I close(destroy) the old form completely and recreate that form? When I don't completely close that old form, because I do this closing and recreating process more than once my App's memory usage gets much higher.

Thanks in advance.

Re: Closing and recreating a form

Henry Minute14-Jun-09 0:14

14-Jun-09 0:14

I am having a little difficulty in understanding where the cause of your problem might lie.

Just to clarify things, what class contains the RestartAll method in the code you posted?

Henry Minute

Do not read medical books! You could die of a misprint. - Mark Twain
Girl: (staring) "Why do you need an icy cucumber?"
“I want to report a fraud. The government is lying to us all.”

Re: Closing and recreating a form

SimpleData14-Jun-09 0:15

14-Jun-09 0:15

RestartAll method is in the mainform class.

Re: Closing and recreating a form

Henry Minute14-Jun-09 0:31

14-Jun-09 0:31

Try this:

private void RestartAll()
{
   // These are not that important, only to transfer the same properties of the form to the new form.
   depo.multipleformlocation=this.Location;
   depo.multipleform = true;
   depo.ekrangoruntusuadedi = 0;

   this.Hide();

   using (mainwindow _mainwindow = new mainwindow())
   {
      _mainwindow.ShowDialog();
   }

   this.Close();

   // Here is my temporary solution (putting old form's thread to sleep infinitely because it shouldn't keep doing what it does)
   Thread.Sleep(Timeout.Infinite);
}

Using the using construct 'should' ensure that _mainwindow is disposed.

Henry Minute

Do not read medical books! You could die of a misprint. - Mark Twain
Girl: (staring) "Why do you need an icy cucumber?"
“I want to report a fraud. The government is lying to us all.”

Re: Closing and recreating a form

SimpleData14-Jun-09 3:05

14-Jun-09 3:05

Thank you. It seems to be working. Should I keep using the Thread.Sleep(Timeout.Infinite); line?

Re: Closing and recreating a form

Henry Minute14-Jun-09 3:13

14-Jun-09 3:13

Try commenting it out and see if everything still works. As you said in your OP it was a temporary solution, and shouldn't be necessary. However, if you still have the old problem after commenting it, the fix hasn't worked and it's back to the drawing-board.

Henry Minute

Do not read medical books! You could die of a misprint. - Mark Twain
Girl: (staring) "Why do you need an icy cucumber?"
“I want to report a fraud. The government is lying to us all.”

Re: Closing and recreating a form

SimpleData14-Jun-09 3:36

14-Jun-09 3:36

I have commented it and seems like it's still working.

Thank you for your help.

Re: Closing and recreating a form

Henry Minute14-Jun-09 3:40

14-Jun-09 3:40

Excellent.

Try to remember the 'using' construct, whenever you create anything IDisposable. I don't always, particularly when I'm 'just trying something out' and forgetting nearly always causes me problems.

Good Luck! Smile | :)

Smile | :)

Henry Minute

Do not read medical books! You could die of a misprint. - Mark Twain
Girl: (staring) "Why do you need an icy cucumber?"
“I want to report a fraud. The government is lying to us all.”

Re: Closing and recreating a form

Luc Pattyn14-Jun-09 4:14

14-Jun-09 4:14

Hi,

I don't understand what it is you are doing here. Either this code runs on the GUI thread, and your Sleep(Infinite) hangs it forever, or it runs on some other thread, and it is not allowed to touch any Controls.

I am afraid your approach is completely wrong.

Confused | :confused:

Confused | :confused:

Luc Pattyn [Forum Guidelines] [My Articles]

DISCLAIMER: this message may have been modified by others; it may no longer reflect what I intended, and may contain bad advice; use at your own risk and with extreme care.

Re: Closing and recreating a form

SimpleData14-Jun-09 4:43

14-Jun-09 4:43

Well, this method doesn't run on the GUI thread but Control.CheckForIllegalCrossThreadCalls is set to false, so all threads are allowed to touch all the Controls.

Re: Closing and recreating a form

Luc Pattyn14-Jun-09 4:49

14-Jun-09 4:49

SimpleData wrote:
so all threads are allowed to touch all the Controls.

That is absolutely false. All CheckForIllegalCrossThreadCalls=false; does is disable the checking (returning to the unhealthy situation that existed in .NET 1.0/1.1), it does not ALLOW anything. Controls are not thread-safe and should be touched only by the thread that created them, and since all Controls are linked somehow (through Control collections, Form Z-Order, etc) that basically means the initial/main/GUI thread is the only one that can touch them. Violating this rule may and will result in abnormal app behavior, typically the GUI freezing pretty soon (or after a possibly long while, but failure is guaranteed).

Smile | :)

Smile | :)

Luc Pattyn [Forum Guidelines] [My Articles]

DISCLAIMER: this message may have been modified by others; it may no longer reflect what I intended, and may contain bad advice; use at your own risk and with extreme care.

Re: Closing and recreating a form

SimpleData14-Jun-09 4:52

14-Jun-09 4:52

That's good to know, I didn't know that.

I will test my application's stability, maybe it won't be a problem. Smile | :)

Smile | :)

Re: Closing and recreating a form

Dave Kreskowiak14-Jun-09 4:58

Dave Kreskowiak

14-Jun-09 4:58

It may pass your tests, but when released into the real world, your code WILL fail. It's just a matter of time before someone out there find the combination of circumstances that will make it happen.

A guide to posting questions on CodeProject[^]

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

Re: Closing and recreating a form

Dave Kreskowiak14-Jun-09 4:55

Dave Kreskowiak

14-Jun-09 4:55

Just because the property is there doesn't mean it should be used.

I concur with Luc, your approach is completely wrong and unsupportable. I really can't suggest a replacement because it isn't clear what you're trying to accomplish.

Also, when you show a form with ShowDialog, you are responsible for calling Dispose on it to free up unmanaged resources before the object goes out of focus and is destroyed. As it stands now, your code leaks system resources, specifically, window handles. Your code, if left running long enough, will eventually crash Windows.

A guide to posting questions on CodeProject[^]

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

Re: Closing and recreating a form

SimpleData14-Jun-09 5:07

14-Jun-09 5:07

What can I do to prevent this?

Re: Closing and recreating a form

Dave Kreskowiak14-Jun-09 5:08

Dave Kreskowiak

14-Jun-09 5:08

Again, we can't really tell you al alternate method without knowing what you're trying to do with this code.

A guide to posting questions on CodeProject[^]

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

Re: Closing and recreating a form

SimpleData14-Jun-09 5:13

14-Jun-09 5:13

I am coding an AntiCheat application which takes screenshots of the game and uploads to the server after the games is closed.

When the app is launched, first the login form appears, if the login info is correct, login from closes and mainform that we are talking about appears. App waits for the user to open a supported game. When it's opened it takes screenshots in random intervals. After the game is closed app uploads the taken screenshots.

After uploading them in order to start waiting for a new game to open, I close the mainform and recreate it. This recreation process is what we are talking about.

Re: Closing and recreating a form

DidiKunz14-Jun-09 7:29

14-Jun-09 7:29

Why can't you hide the form, instead of close and reopen?

Regards: Didi

Re: Closing and recreating a form

SimpleData14-Jun-09 8:19

14-Jun-09 8:19

Because I don't want to keep an extra copy of that form at the back and I need another copy of it.

Re: Closing and recreating a form

Dave Kreskowiak15-Jun-09 0:39

Dave Kreskowiak

15-Jun-09 0:39

Why?? If your code is written correctly, you shouldn't have to do this at all. The code should just fall back to waiting for a suported game to launch.

A guide to posting questions on CodeProject[^]

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

Re: Closing and recreating a form

SimpleData15-Jun-09 1:09

15-Jun-09 1:09

I will try to make it work that way.

Thanks.

Re: Closing and recreating a form

Henry Minute14-Jun-09 9:57

14-Jun-09 9:57

I noticed the Thread.Sleep after the this.Close(), but as I could not even start to imagine what was, or was supposed to happen. I therefore very deliberately refrained from mentioning it.

Now you have gone and stirred the whole thing up again! Smile | :)

Smile | :)

Henry Minute

Do not read medical books! You could die of a misprint. - Mark Twain
Girl: (staring) "Why do you need an icy cucumber?"
“I want to report a fraud. The government is lying to us all.”

Re: Closing and recreating a form

Luc Pattyn14-Jun-09 10:08

14-Jun-09 10:08

Henry Minute wrote:
Now you have gone and stirred the whole thing up again!

Yeah, that's me. Always fighting against those silly Thread.Sleep(Timeout.Infinite); statements which waste an entire stack without achieving anything.

Sorry for being a tad more radical; "Try commenting it out and see if everything still works..." is not really my style.

Poke tongue | ;-P

Poke tongue | ;-P

Luc Pattyn [Forum Guidelines] [My Articles]

DISCLAIMER: this message may have been modified by others; it may no longer reflect what I intended, and may contain bad advice; use at your own risk and with extreme care.

Re: Closing and recreating a form

Henry Minute14-Jun-09 10:17

14-Jun-09 10:17

Blush | :O

Henry Minute

Do not read medical books! You could die of a misprint. - Mark Twain
Girl: (staring) "Why do you need an icy cucumber?"
“I want to report a fraud. The government is lying to us all.”

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