Re: help:C# application and Databases - C# Discussion Boards

Mridang Agarwalla17-Oct-05 21:05

17-Oct-05 21:05

I have slight problem. I've pondered over it for quite some time now but I cant seem to figure it out. Here's how it goes -

I have a form on which I have placed button. Now when the button is clicked a function is called which displays another form which has two radio buttons on it and a commandbutton. When the user selected wither of the radiobuttons and then clicks the command button, I want the result of this form to be passsed back to the calling form. In short, I want it to work similar to a dialogbox.

Re: call a form and return the result

S. Senthil Kumar18-Oct-05 0:33

S. Senthil Kumar

18-Oct-05 0:33

Just set the Form.DialogResult[^] property to whatever you want within the form. You can then access it like

SomeForm f = new SomeForm();
if (f.ShowDialog() == DialogResult.XXX)
{
   // Do something.
}

Regards
Senthil
_____________________________
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Re: call a form and return the result

Rob Philpott18-Oct-05 0:48

Rob Philpott

18-Oct-05 0:48

The more usual way of doing this would be to provide methods/fields/properties etc. on the second form which the first can use to query what happened (in this case maybe a boolean or enum property denoting which radio button was selected). You can then invoke the second form in this manner:

private void button1_Click(object sender, System.EventArgs e)
{
Form2 form2 = new Form2();
form2.ShowDialog(this);

// check we received an OK and not a CANCEL
if (form2.DialogResult == DialogResult.OK)
{
// .. query form 2 using the new methods/properties/fields
// and do your stuff
}
}

Rob Philpott

stop a process on remote computer

Prashant Gadhave17-Oct-05 20:27

Prashant Gadhave

17-Oct-05 20:27

I have all the processes running on remote computer in Process array.I want to kill one specific process.how to do it ?

help:C# application and Databases

jith - iii17-Oct-05 19:42

jith - iii

17-Oct-05 19:42

My application is in C#.net,Asp.net and access .The database has to be changed from access as it causes serious perofomance issues while it faces cuncurrent usage.My application would be used by nearly 50 users(might be more).

Which open source database i can use over here.I am thinking about interbase,mySql and MSDE .which would be ideal for my application.

Or can i use xml as datasore.But i am not quite sure about cuncurrency contol and datasecurity if i use xml.

Please Comment on these.Its really confusing since i found somany opensource databases(Also postgress SQL,Firebird).

Thanks in advance....

Re: help:C# application and Databases

Guffa17-Oct-05 21:14

Guffa

17-Oct-05 21:14

An Access database has a limit of 64 concurrent connections. If it a web application you would typically never come close to this with as few as 50 users. Each connection lasts only a few milliseconds, so mostly there are only a few connections open.

What kind of performance issues are you facing?

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Re: help:C# application and Databases

jith - iii17-Oct-05 22:28

jith - iii

17-Oct-05 22:28

Thank you for the reply

The error message I am getting is

could not update:database is currently locked by admine on machine 'machine name':Microsoft Jet Database Engine.

I was told that access is not a good database when it confronts multiusers.
Thats why I am planning to move other opensource databases.

in access What is the maximum number of users who can perform operations on the same table AT THE SAME TIME.

Re: help:C# application and Databases

Guffa18-Oct-05 0:20

Guffa

18-Oct-05 0:20

There is no locking of a table when reading it, so any number of users may read the same table at once.

Several users may update the same table, as long as they do not update the same records. Updates to records that are locked are normally delayed until they are unlocked, and the user hardly notices the delay.

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Re: help:C# application and Databases

jith - iii18-Oct-05 0:35

jith - iii

18-Oct-05 0:35

my application is still on the developement stage .I fear that access may cause some problem in cuncurrency control (also i heard that there is a possible chance of database getting corrupted).

Thats why i am considering mySQL or interbase .What about these database.Mainly i dont want to spent money on database.

Re: help:C# application and Databases

André Ziegler18-Oct-05 7:43

André Ziegler

18-Oct-05 7:43

jitAtran wrote:
Thats why i am considering mySQL or interbase

You should use FireBird. The DataBase is OpeSource and you can use it in your programm for free. There is also a managed provider for FireBird here:

http://firebird.sourceforge.net/index.php?op=files&id=netprovider

And with the MultiGenerationArchictecture of FireBird, there is no locking Smile | :)

I love FireBird Smile | :)

Re: help:C# application and Databases

jith - iii18-Oct-05 18:05

jith - iii

18-Oct-05 18:05

Can u compare mySql and firebird.Since mySql is being used widely ,many friends of mine suggesting it.(Even they havent heard about Firbird).

And also mySql seems to be very fast.but does not have features like stored procedure,trigger ets.

is firebird being used for commercial application.Is it released fully or any beta version.

Expecting a reply..

Re: help:C# application and Databases

André Ziegler20-Oct-05 8:03

André Ziegler

20-Oct-05 8:03

Hi,

jitAtran wrote:
Can u compare mySql and firebird.Since mySql is being used widely ,many friends of mine suggesting it.(Even they havent heard about Firbird).

FireBird is an OpenSource project based on den OpenSource-Code of Borland Interbase 6.0. Because of this, FireBird is mostly used by devolopers of Borland Delphi and C++ Builder.

jitAtran wrote:
And also mySql seems to be very fast.but does not have features like stored procedure,trigger ets.

In my opinion FireBird ist faster because of the features that MySQL doesn't have like StoredProcedures, triggers etc. And FireBird supports transactions. This is a must have feature today and MySQL only supports transactions with InnoDB.

jitAtran wrote:
is firebird being used for commercial application.

As I said, a lot of Borland Developers use it in commercial applications.

jitAtran wrote:
Is it released fully or any beta version.

FireBird 1.5 is the latest stable release of FireBird. You can downlaod it here:

http://www.ibphoenix.com/main.nfs?a=ibphoenix&page=ibp_download

FireBird 2.0 is still in development (alpha) and will have more enhancements.

For more information visit IBPhoenix: http://www.ibphoenix.com/

André

Interaction between main program and dll

dmee17-Oct-05 19:39

dmee

17-Oct-05 19:39

Hi all!

Could anybody give me an example of following:

1) Main program in C# that calls function Foo(Handle_of_My_Form) declared in my dll.

2) Dll in C++ with implementation of Foo that just calls PostMessage(Handle_of_My_Form, WM_USER, 0, 0).

3) Finally, main program catches this messages and show MessageBox "All right! I've caught it!".

Please, help - I need to do this task as soon as possible.

--
Sincerely,
Dmitri

Re: Interaction between main program and dll

Rob Philpott18-Oct-05 0:27

Rob Philpott

18-Oct-05 0:27

Is the DLL implementation using managed or unmanaged C++?

Rob Philpott

Re: Interaction between main program and dll

dmee18-Oct-05 5:19

dmee

18-Oct-05 5:19

I'm sorry but what is the difference?

How to add right-click menu to a tree view control

deejagan17-Oct-05 19:07

deejagan

17-Oct-05 19:07

Can anyone please tell me how to add a right-click menu to a tree view control?

Any help is appreciated.

Thanks!

Re: How to add right-click menu to a tree view control

Andrew Kirillov17-Oct-05 19:16

Andrew Kirillov

17-Oct-05 19:16

Hello

You need to use ContectMenu property of TreeView.

With best regards,
Andrew Kirillov, MCP x 3
Prize winner, August 2005

Re: How to add right-click menu to a tree view control

deejagan17-Oct-05 19:34

deejagan

17-Oct-05 19:34

Hi,
Thanks for your reply. But in spite of setting the contextMenu for the tree view control, I am not able to see the menu upon right-click.

Sorry if my question is silly. I still do not understand how to associate this Menu to the right-click of the tree view item.

Convert Uint32 to byte[4]

rushing17-Oct-05 18:52

rushing

17-Oct-05 18:52

How to convert an uint32 integer to a byte[4]?
Moreover, put the byte[4] into a byte[] buffer.
Thanks!

Re: Convert Uint32 to byte[4]

Andrew Kirillov17-Oct-05 19:22

Andrew Kirillov

17-Oct-05 19:22

Hello

You can try the next code:

uint	i = 0xABCDEF12;
byte[]	bytes = new byte[4]
	{
		(byte) (i & 0xFF),
		(byte) ((i >> 8) & 0xFF),
		(byte) ((i >> 16) & 0xFF),
		(byte) (i >> 24)
	};

With best regards,
Andrew Kirillov, MCP x 3
Prize winner, August 2005

Re: Convert Uint32 to byte[4]

leppie17-Oct-05 20:56

leppie

17-Oct-05 20:56

BitConvertor.ToBytes()

^{xacc-ide 0.0.99-preview5 now with C#, C, IL, XML, Nemerle, IronPython and Boo highlighting support!}

StringConverter

Anonymous17-Oct-05 18:18

Anonymous

17-Oct-05 18:18

I would like to write custom stringconverter for my own class so propertygrid can display correct string representation of the object.

but how to override method to convert string back to the object?

I wonder how microsoft does it with bitmaps or collections. Collection object is converted into the string as "(Collection)". but how this string is converter back to the actual collection? does anyone know what's the trick here?

thank you
luke

Re: StringConverter

Andy Brummer17-Oct-05 18:27

Andy Brummer

17-Oct-05 18:27

Check out this topic on MSDN.

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpguide/html/cpconGeneralizedTypeConversion.asp[^]

I can imagine the sinking feeling one would have after ordering my book,
only to find a laughably ridiculous theory with demented logic once the book arrives - Mark McCutcheon

TreeNode leftClick with mouse

ppp00117-Oct-05 16:54

ppp001

17-Oct-05 16:54

Hi,

When the treeView control's nodes are right-clicked,
the selectedNode of the treeView won't be changed unless
it is a left-click mouse event.

My problem is that I associated context menu to the tree
nodes, so user just right click the node to use the context
menu, however the selectedNode isn't the node that the context menu
is launched.

So how can I set the selectedNode to the node that is right-clicked ?

Thanks

Re: TreeNode leftClick with mouse

S. Senthil Kumar17-Oct-05 20:44

S. Senthil Kumar

17-Oct-05 20:44

Subscribe to the MouseDown event of the TreeView and do this

if (e.Button == MouseButtons.Right)
{
	Point point = new Point(e.X, e.Y);
	TreeNode node = treeView.GetNodeAt(point);
	if (node == null)
             return;
	treeView.SelectedNode = node;

Regards
Senthil
_____________________________
My Blog | My Articles | WinMacro

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