Re: i am a beginner in c# please help me - C# Discussion Boards

Re: MySQL persisent connection

19-Dec-06 2:05

Keeping a connection open for a long time is a very bad idea. It reduces the scalability of sites, as well as leading you to rely on connections being open when this is not necessarily the case.

Suppose that your application opens a connection and then does some work before attempting to save to the database. In the meantime, MySQL goes down and then comes back up. When you attempt to save, the connection will not be open - you will only think that it is. The first hit that you do to the database will then fail.

I would be surprised if the connections to the database weren't pooled, in which case you wouldn't always be creating a new connection. Instead, you would be pulling a connection out of the pool which is not very expensive at all.

the last thing I want to see is some pasty-faced geek with skin so pale that it's almost translucent trying to bump parts with a partner - John Simmons / outlaw programmer

Deja View - the feeling that you've seen this post before.

wedtm19-Dec-06 21:46

wedtm

19-Dec-06 21:46

Amazing, that's what I thought, thank you for your expertise in the situation!

I'll just call a MySQL function each time I need it...

Thank you!

Adding SharePoint Presence to Webcontrols TreeView?

Scholesy1819-Dec-06 1:53

Scholesy18

19-Dec-06 1:53

Can anybody tell me if it's possible to add the SharePoint Presence functionality to the IE Webcontrols tree diagram in C#.

I have tried to add the following to the treenode text but this doesn't seem to work.

individualUser.Text = User.Name+" ";

links between Matlab and C#

charchabil0319-Dec-06 1:39

charchabil03

19-Dec-06 1:39

i ' m asking if i can make a graphic interface with C# (or.net) for a simulator done in matlab language.

please if u can send reply on ralph_habib@hotmail.com.thanks for your support.

Regards
Ramy

Re: links between Matlab and C#

Paul Conrad25-Dec-06 18:31

Paul Conrad

25-Dec-06 18:31

matlab and .NET Google Search[^] might help you. In the future, it is a good idea not to include your email address in public view. If someone wants to email you, they'll click on the |Email| link...

If you try to write that in English, I might be able to understand more than a fraction of it. - Guffa

Threading query

deep719-Dec-06 1:04

deep7

19-Dec-06 1:04

Hi,
In my application i'm having a picture box which is shown when a certain button is clicked. Also simutaneously, im calling a procedure using threading which will perform an operation using webservice and show results in a datagrid(i'm using a 'component one truedbgrid'). After the threading operation is done, i'm making the picture box invisible.

My problem is as soon as the picturebox becomes invisible, the scrollbar in the datagrid just goes off..and i cant scroll in the grid. I cant understand why this is happening. Can anyone plz help me in this? I'd really appreciate that..
Thanks,
Deepa

Pete O'Hanlon19-Dec-06 1:24

19-Dec-06 1:24

This doesn't sound like a problem with threading. As a test, why not show the picturebox and then retrieve the information from the DB without any thread code. Once the data has been returned, make the picture box invisible again. Does the problem still occur? If so, it sounds like it's a problem with TrueDbGrid - and that should be raised through their support/forums.

deep719-Dec-06 1:36

deep7

19-Dec-06 1:36

Hi,
i tried first without using threading...but since the results take little time to load in the datagrid, the picturebox hangs. The picturebox is .gif file, it shows a plane moving, which i've used instead of a progressbar. But when i click on the button, the picturebox appears, but the plane doesn't move..its hanged...it becuase of the search procedure that happens on buttonclick event...
Thats why i thought i should use threading and put the search procedure in the threading job..so the gif shows the plane moving fine...the datagrid also loads fine with the data..only thing is as soon as the pic box is invisible, the scrollbar in the grid goes off

Pete O'Hanlon19-Dec-06 2:02

19-Dec-06 2:02

Errm - OK. That wasn't what I was asking. What I was suggesting was that you removed the threading from the problem to see if the symptoms are the same when you run the code without it.

althamda19-Dec-06 1:24

althamda

19-Dec-06 1:24

Have you tried playing with the ScrollBars properties in your TrueDBGrid?

deep719-Dec-06 1:38

deep7

19-Dec-06 1:38

There a property for the grid 'ScrollTrack' this boolean type..so it is set to true...The scroll bar is seen when the search results come in the datagrid, but when the picture box is invisible, then scrollbar also goes off...i dont get why this happens

Code to convert

quiteSmart19-Dec-06 1:01

quiteSmart

19-Dec-06 1:01

hi can anyone convert this VB lines to C#?

Dim RAW, arHex_Char_Set, mCounter, mKey, mOffset, Raw_Key, Hex_Cryp_Data<br />
        Dim EPassword As String = TextBox1.Text<br />
        Raw_Key = Right(EPassword, Len(EPassword) - InStr(EPassword, "|"))<br />
        mOffset = Right(Raw_Key, Len(Raw_Key) - InStr(Raw_Key, "|"))<br />
        mKey = Hex_Converter(Left(Raw_Key, InStr(Raw_Key, "|") - 1)) - Hex_Converter(mOffset)<br />
        Hex_Cryp_Data = Left(EPassword, Len(EPassword) - (Len(Raw_Key) + 1))<br />
    <br />
        arHex_Char_Set = Split(Hex_Cryp_Data, Hex(mKey))<br />
         <br />
        For mCounter = 0 To UBound(arHex_Char_Set)<br />
            RAW = RAW & Chr(Hex_Converter(arHex_Char_Set(mCounter)) / mKey)<br />
        Next<br />

thanks

Pete O'Hanlon19-Dec-06 1:21

19-Dec-06 1:21

Yes. Can you? Big Grin | :-D

Seriously, have a try, and if you are having problems, post up what you have done and we will take a look at them.

quiteSmart19-Dec-06 1:28

quiteSmart

19-Dec-06 1:28

ok man,
i tried it before i post, i got the first 3 lines and i am stuck

here are the first 3 lines

<br />
int  mCounter, mHxx_Var;<br />
int multiply = 0;<br />
<br />
if (Hex_Var != "")<br />
{<br />
                Hex_Var = Hex_Var.ToUpper();<br />
                Hex_Var = reverseString(Hex_Var);<br />

P.S: reverseString is a hand made function Laugh | :laugh:

Pete O'Hanlon19-Dec-06 2:33

19-Dec-06 2:33

To get you started, here's a rough copy:

string raw_key = value.Substring(value.IndexOf("|") + 1);
string offset = raw_key.Substring(raw_key.IndexOf("|") + 1);
string key = raw_key.Substring(0, raw_key.IndexOf("|"));
string hex_cryp_data = value.Substring(0, value.IndexOf("|"));
string[] split = hex_cryp_data.Split('^');
foreach (string item in split)
{
	Console.WriteLine(item);
}

It doesn't have in your calls to the hex_convert functions, but you should be able to get an idea of how it works from this.