Re: got problem with sequence of event execution - C# Discussion Boards

Mogyi16-Oct-08 4:10

16-Oct-08 4:10

I added to rollback my dll too, the problem is: if I call Rollback directly nothing happens, if I say 'throw new InstallException("Canceld by user");' it rolls back nicely but before that, a general error MessageBox is shown...

What is best way?

Majid_grok16-Oct-08 2:45

Majid_grok

16-Oct-08 2:45

Hello my friends!

I wants to create a chat application as client-server (one server and multiple clients). Please help me that which way is best to make it. With Sockets or Remoting objects (HttpChannel or TcpChannel)?
As you know if increases clients, server traffic is a serious problem.
Please describe your advices and suggestions...

Thanks.

Re: What is best way?

Nagy Vilmos16-Oct-08 3:06

Nagy Vilmos

16-Oct-08 3:06

You have two options for this:
1) Do some [deleted] research (qv google)
2) Post your requirements on rent-a-coder

Panic, Chaos, Destruction.
My work here is done.

got problem with sequence of event execution

Krazy Programmer16-Oct-08 2:37

Krazy Programmer

16-Oct-08 2:37

Hi
What i want to do ?

I am displaying a picture in picture box
When user drags the picture then it has to appear in the another picture box

What i Did ..

private void pictureBox1_MouseUp(object sender, MouseEventArgs e)
{
isdragged = true;
}

private void pictureBox2_MouseEnter(object sender, EventArgs e)
{
if (isdragged == true)
{
pictureBox2.ImageLocation = picpath;
isdragged = false;
}

}

isdragged is a boolean variable ....
picpath is a string i have stored the image location

After clicking on the picturebox1 and dragging it to the picture box 2 .. private void pictureBox2_MouseEnter event is not raising
I mean to say no effect when mouse enters into the picturebox2

I know i have done a mistake somewhere

Please tell me what i must do to solve this

(* Dont tell me to read a basic book .. i have read it twice ...*)

Joking

Thanks and Regards

If You win You need not Explain............
But If You Loose You Should not be there to Explain......

Re: got problem with sequence of event execution

Guffa16-Oct-08 3:17

Guffa

16-Oct-08 3:17

If you click and drag, you don't get any MouseUp event in the first picture box...

Krazy Programmer wrote:
(* Dont tell me to read a basic book .. i have read it twice ...*)

Third time is the charm. Wink | ;)

Despite everything, the person most likely to be fooling you next is yourself.

Re: got problem with sequence of event execution

Krazy Programmer16-Oct-08 19:44

Krazy Programmer

16-Oct-08 19:44

Guffa wrote:
Third time is the charm.

YES , I know someone will tell this .. but not the correct answer

Anyway Thanks

I will be reading it again

If You win You need not Explain............
But If You Loose You Should not be there to Explain......

Re: got problem with sequence of event execution

Guffa17-Oct-08 13:38

Guffa

17-Oct-08 13:38

Krazy Programmer wrote:
but not the correct answer

I think that it is. If you don't understand that you don't get an MouseUp event on a control where you don't release the mouse button, you are clearly missing some of the most fundamental ideas of the graphical interface and the event handling. The logical solution would be to go back and fill in the gaps.

Despite everything, the person most likely to be fooling you next is yourself.

Re: got problem with sequence of event execution

nelsonpaixao16-Oct-08 12:36

nelsonpaixao

16-Oct-08 12:36

why drag?
why dont you browse a picture and load it in a picturebox?

OpenFileDialog open_file_dialog = new OpenFileDialog();
DialogResult dialog_result = open_file_dialog.ShowDialog();
if (dialog_result == DialogResult.OK)
{
mypicturebox.ImageLocation = open_file_dialog.FileName;

// something more would be ...
//string Image_Path = open_file_dialog.FileName;
//Image img = Image.FromFile(open_file_dialog.FileName);
//...
}

After that, dont know if you want a path to the picture or load/save them from/to a database. D'Oh! | :doh:

nelsonpaixao@yahoo.com.br

trying to help & get help

Re: got problem with sequence of event execution

Krazy Programmer16-Oct-08 19:44

Krazy Programmer

16-Oct-08 19:44

nelsonpaixao wrote:
why drag?

Requirement is drag and drop

If You win You need not Explain............
But If You Loose You Should not be there to Explain......

Threads and WinForms

Programm3r16-Oct-08 1:45

Programm3r

16-Oct-08 1:45

Hi all,

A while ago I posted a question on this topic, and received a great response. I made use of the article posted by Sacha Barber called Beginners Guide To Threading In .NET Part 5 of n. In this article he uses the SynchonizationContext to marshall the background work to the UI thread.

But the thing is that when I send response back to a listview on the GUI thread x amount of time in quick succession the whole application just freezes / hangs.

Is this a bad idea doing it like this or am I just doing something wrong (maybe a different approach)

private SynchronizationContext context;
.....
.....
//set up the SynchronizationContext
context = SynchronizationContext.Current;
if (context == null)
{
    context = new SynchronizationContext();
}
.....            
.....            
try
{
    for (int i = 0; i < (int)e.Argument; i++)
    {
        context.Send(new SendOrPostCallback(delegate(object state)
        {
            lViewTransactionHistory.Items.Add(lViewTransactionHistory.Items.Count.ToString(), DateTime.Now.ToLongTimeString(), 0);

        }), null);
    }
}
catch (InvalidOperationException oex)
{
    MessageBox.Show(oex.Message);
}

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

Programm3r
My Blog: ^_^

Re: Threads and WinForms

Alan N16-Oct-08 1:59

Alan N

16-Oct-08 1:59

Hi,
Is that 1) freeze/hang and never recover or 2) freeze/hang and then come back to life after a period of time. If it's the latter then you are sending too many messages to the UI thread and overwhelming the message queue. You may be able to work around this by sending the UI updates in batches rather than individually.

Alan.

Re: Threads and WinForms

Programm3r16-Oct-08 2:03

Programm3r

16-Oct-08 2:03

Alan N wrote:
Is that 1) freeze/hang and never recover or 2) freeze/hang and then come back to life after a period of time.

Good question, I haven't waited long enough to check if the UI comes back to life, but I understand your point. Thank you Smile | :)

Regards,

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

Programm3r
My Blog: ^_^

Re: Threads and WinForms

Programm3r16-Oct-08 2:13

Programm3r

16-Oct-08 2:13

Hi,

Answer: 1) freeze/hang and never recover

How should this be treated?

Many thanks again
Kind regards,

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

Programm3r
My Blog: ^_^

Re: Threads and WinForms

Giorgi Dalakishvili16-Oct-08 2:30

Giorgi Dalakishvili

16-Oct-08 2:30

I am not sure about this case but generally it's better to use AddRange method for adding many items to the listview. Also, use BeginUpdate() EndUpdate() methods so that your listview isn't repainted any time an item is added.

Giorgi Dalakishvili

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Re: Threads and WinForms

Programm3r16-Oct-08 2:49

Programm3r

16-Oct-08 2:49

Giorgi Dalakishvili wrote:
Also, use BeginUpdate() EndUpdate() methods so that your listview isn't repainted any time an item is added.

Thanks for the response. I noticed that when I change the listview control to a listbox the problem does not occur anymore, so I will try the above mentioned response.

Many thanks
Kind regards,

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

Programm3r
My Blog: ^_^

Re: Threads and WinForms

Programm3r16-Oct-08 3:05

Programm3r

16-Oct-08 3:05

Ok, so I'm adding the items using the AddRange method and I am making use of the BeginUpdate() EndUpdate() methods before and after I have added the item range. But if I add the items to the listview in quick succession, the UI and for that matter the whole application still freezes / hanges Confused | :confused:

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

Programm3r
My Blog: ^_^

Re: Threads and WinForms

Giorgi Dalakishvili16-Oct-08 3:19

Giorgi Dalakishvili

16-Oct-08 3:19

Which overload of AddRange method are you using? Try using the one that takes ListViewItem[] as a parameter.

Giorgi Dalakishvili

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Re: Threads and WinForms

Programm3r16-Oct-08 3:25

Programm3r

16-Oct-08 3:25

To be exact:

if (this.InvokeRequired)
{
	this.Invoke(new EventHandler(delegate
	{
		lViewTransactionHistory.BeginUpdate();
		ListViewItem item1 = new ListViewItem(DateTime.Now.ToLongTimeString(),0);
		item1.SubItems.Add(i.ToString());
		item1.SubItems.Add(TcpServer.connectData[i].Request);
		item1.SubItems.Add("OK");
		item1.SubItems.Add("CMD_PING");
		lViewTransactionHistory.Items.AddRange(new ListViewItem[] { item1 });
		lViewTransactionHistory.EndUpdate();
	}));
}
else
{
...
}

So yes I am using the correct method overload.

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

Programm3r
My Blog: ^_^

Re: Threads and WinForms

Giorgi Dalakishvili16-Oct-08 3:31

Giorgi Dalakishvili

16-Oct-08 3:31

You are doing practically the same thing you were doing in your original code. Instead of adding items one by one, store them in an array and add them in batch. If you are using backgroundworker you can use Result property to store listviewitem[] and access it when the worked is completed. In this case you can just add the items without the need of Invoke.

Giorgi Dalakishvili

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Re: Threads and WinForms

Programm3r16-Oct-08 3:39

Programm3r

16-Oct-08 3:39

Ok, I understand what your saying, the only thing is that I wanted to display each of the events of the TCP server as it was received, real time. But if I put it into a batch / array and display it every x amount of time, this won't be the case. So this is what I wanted to achieve. But thank you very much for the info and help.

regards,

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

Programm3r
My Blog: ^_^

Re: Threads and WinForms

Giorgi Dalakishvili16-Oct-08 5:44

Giorgi Dalakishvili

16-Oct-08 5:44

If you are using BackGroundWorker, you can report progress when event is received and pass necessary info or the item to it. In the ProgressChanged event handler you will not invoke to update listview.

Giorgi Dalakishvili

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How to change the height property of panel dynamically

mharoonkhan16-Oct-08 1:04

mharoonkhan

16-Oct-08 1:04

i have placed a data grid inside a panel if the data grid have the record the panel will expand and if the data grid don't have a data then the height of the panel will be zero. how
i change a height property of a Panel according to the click of the
user how to set the height property and scroll property at run time

KnightGuy

Re: How to change the height property of panel dynamically

EliottA16-Oct-08 2:08

EliottA

16-Oct-08 2:08

From what I understand you are trying to do, you are trying to set the size of your panel to be equal to that of the contents inside of it?

You can loop for that

int i = 0;
int max = panel1.controls.items.count -1;
panel1.height = 0;
while i <= max
{
panel1.size += panel1.controls.items.i.height;
i++;
}

'edit
you can suspend your layout so you don't see it resize

C# Print DataGridView

Socheat.Net15-Oct-08 23:42

Socheat.Net

15-Oct-08 23:42

Dear,

Can anyone give me a code that can print DataGridView in C#.NET 2005?

Socheat

Re: C# Print DataGridView

Giorgi Dalakishvili15-Oct-08 23:53

Giorgi Dalakishvili

15-Oct-08 23:53

I can't but Google can Smile | :)

Giorgi Dalakishvili

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