C# Discussion Boards - CodeProject

elena1234513-Jan-04 6:15

13-Jan-04 6:15

Problem: I need to call a function when either a combo box selection is changed or some new text is typed into the combo box.

SelectedIndexChanged takes care of the first half, but I can't figure out the OnTextChanged part.
Does anyone know what event is triggered when a user types in text into the ComboBox?

I know there are Enter and Leave events... but then I will have to keep track of whether the text changed myself, and that's my very last resort, because I have a gut feeling (called laziness Poke tongue | ;-P

) that there has to be a better way to do this Smile | :)

Does anyone have any ideas?

Thank you,

Elena

Elena

Re: ComboBox events

Nick Parker13-Jan-04 6:50

Nick Parker

13-Jan-04 6:50

elena12345 wrote:
Does anyone have any ideas?

When you form loads up, store an intial value within a public variable, the add an event handler for KeyDown, something like this should work:

public string buffer = "something";


                private void comboBox1_KeyDown(object sender, System.Windows.Forms.KeyEventArgs e)
		{
			if(e.KeyCode == Keys.Enter)
			{
				ComboBox cb = sender as ComboBox;
				if(cb != null)
				{
					if(cb.Text != buffer)
					{
						// Call your function here if text changed...
					}
				}
			}
		}

- Nick Parker
My Blog

Re: ComboBox events

elena1234513-Jan-04 8:09

elena12345

13-Jan-04 8:09

Hi Nick,

Thank you for your reply.

I don't see the advantage of using the KeyDown event instead of the Leave event. I got to store the value and do everytyhing manually anyway.
Plus neither KeyDOwn nor Leave will catch the cases when the ComboBox is set programmatically.

I guess there is no ComboBox.OnSelectedValueChaged silver bullet. Frown | :(

Thanks again,

Elena

Re: ComboBox events

Heath Stewart13-Jan-04 8:49

Heath Stewart

13-Jan-04 8:49

The TextChanged event fires if your ComboBox.DropDownStyle is set to ComboBoxStyle.DropDown. The unfortunate part is that is fires for every character typed, so you might want to handle the LostFocus event or the Validating event in order to add the new text or to call the function after the text is entered in its entirety.

-----BEGIN GEEK CODE BLOCK-----
Version: 3.21
GCS/G/MU d- s: a- C++++ UL@ P++(+++) L+(--) E--- W+++ N++ o+ K? w++++ O- M(+) V? PS-- PE Y++ PGP++ t++@ 5 X+++ R+@ tv+ b(-)>b++ DI++++ D+ G e++>+++ h---* r+++ y+++
-----END GEEK CODE BLOCK-----

Re: ComboBox events

elena1234513-Jan-04 10:14

elena12345

13-Jan-04 10:14

For those interested, here is what I ended up doing.
But first a little mode details on my case: it's a login dialog, and whenever the value in ServerComboBox changes I have to go and pull a list of databases off the server and put it into the DBComboBox.

This might look like an overkill with ServerComboBox.Leave, ServerComboBox.SelectedIndexChanged, and DBComboBox.DropDown handlers.
I would skip Leave & SelectedIndexChanged and just do DropDown if I didn't have to make a call to the server. When I do the call the the server on DropDown, the GUI hangs a little, so it's better to do it right when the ServerComboBox is changed.

Why do I have the DropDown handler at all: there is one case when Leave & SelectedIndexChanged don't do it: on startup when there is no history in the registry and we use the hardcoded default value for the ServerComboBox.

I don't know if I am making sence or it's too specific to my problem. Here it is anyway:
Let me know if you see any way to improve the code.

So here it is:

/// <summary>
/// The DbComboBox is dependent on the ServerComboBox and has to display the databases
/// available for the selected server.
/// </summary>
class DbComboBox : ComboBox
{
string m_onEnterServerName = ""; //the name of the server we pulled databases from the last time
ComboBox m_ServerComboBox;

/// <summary>
/// Constructor
/// </summary>
/// <param name="ServerComboBox">server combo box that we need to display Dbs for</param>
public DbComboBox(ComboBox ServerComboBox):base()
{
m_ServerComboBox = ServerComboBox;

//handles user changes but not programatic updates
//programatic updates are handled by SelectedIndexChange and a call to RefreshDbHistory
//from Server property in the SignIn dialog
m_ServerComboBox.Leave += new System.EventHandler(ServerChangedEventHandler);

//handles selection change, but not when the user types in something new
m_ServerComboBox.SelectedIndexChanged += new System.EventHandler(ServerChangedEventHandler);

//in case there is no history and login defaults we need to load DBs for the
//hardcoded default.
this.DropDown += new System.EventHandler(ServerChangedEventHandler);
}

/// <summary>
/// Event handler that is called when we suspect that the selection for the server combo box has changed
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void ServerChangedEventHandler(object sender, System.EventArgs e)
{
RefreshDbHistory();
}

/// <summary>
/// Goes to the server, pulls databaselist, populates combobox
/// </summary>
public void RefreshVaultDbHistory()
{
string newServer = m_ServerComboBox.Text;
if ((!newServer.Equals("")) && (!newServer.Equals(m_onEnterServerName)))
{
....
}
}
}

Elena

unzip zip file

murali_utr13-Jan-04 6:00

murali_utr

13-Jan-04 6:00

Hi,
for my web application, i need to unzip my zip file on server through code. any one help to me.

thanks in advance.
Murali.M

Re: unzip zip file

Judah Gabriel Himango13-Jan-04 6:14

Judah Gabriel Himango

13-Jan-04 6:14

The guys from #develop have created a nice .Net zip libray, see icsharpcode.net for a download.

The graveyards are filled with indispensible men.

Re: unzip zip file

murali_utr13-Jan-04 9:20

murali_utr

13-Jan-04 9:20

Hi,

thanks for ur help

Have A Nice Day

Licensing solution per SQL Database?

Alex Korchemniy13-Jan-04 4:56

Alex Korchemniy

13-Jan-04 4:56

I have a software package that gets installed on a local sql server and the customer can run as many clients as they need. What I need to be able to do is license the package by securing the sql server. For each "sub-office" there should be a license. Each sub-office has its own database on the sql server.

Blush | :O

I know that this isn't the right forum. I just though maybe I can get a quick answer since this one has a larger audience. If anything I can implement a custom solution not based on the sql server. Suggestions welcomed.

Re: Licensing solution per SQL Database?

Heath Stewart13-Jan-04 5:39

Heath Stewart

13-Jan-04 5:39

So basically you want to license the database itself? We have a similar setup with our flagship product where a single database manages the accounts that can access each of the company databases (or sub-office database in your case). Similar to you, we allow unlimited user accounts. You could even forego this and just use Windows Authentication using SSPI. The thing that maintains how many people can access each database at a time is a .NET Remoting object that caches the current license count for each company (just in case the Remoting object shuts down or something). It hands out licenses and takes care of decrementing those counts when a client disconnects. The latter part is problematic, however, since if your client application crashes there's not really any good way to decrement the count since the clean-up code didn't run. If you don't have to expose your Remoting object through IIS in order to hang-off port 80, you could always poll clients by implementing your own ILease and returning that in GetLifetimeService.

As far as limiting connections in SQL Server, all you can do is limit licenses for a SQL Server instance, but that's nothing that a DBO couldn't change.

Re: Licensing solution per SQL Database?

Alex Korchemniy13-Jan-04 5:49

Alex Korchemniy

13-Jan-04 5:49

Awesome! That is exactly what I was thinking about doing.

One little question. I have my clients automatically find the sql server (multiple sql servers are possible also, I do searching using SQLDMO.ListAvailableSQLServers). What would be the best way of storing the URI? I was thinking maybe store it on the SQL database and have the client look it up. It URI doesn't work or license check fails then client will shutdown.

Re: Licensing solution per SQL Database?

Heath Stewart13-Jan-04 5:52

Heath Stewart

13-Jan-04 5:52

Sounds like a good idea. That way, you wouldn't have to worry about clients configuring two different properties - one for the SQL Server connection string and one for the Remoting object URI.

Convert HTML to PDF Stream into DB

Regardt13-Jan-04 2:54

Regardt

13-Jan-04 2:54

Hi

I would really appreciate it if anybody can help me!! I must convert a HTML page ..images include into a PDF file and stream the PDF file into a DB.

I have searched the net without any real success.

Thanks

Regardt

Africa is a though country
--"Hello daar vir die Afrikaans sprekende"--

Re: Convert HTML to PDF Stream into DB

Alex Korchemniy13-Jan-04 4:48

Alex Korchemniy

13-Jan-04 4:48

You have to split this up into two part. First convert then encode and send to server.

Take a look at this site: http://www.verypdf.com/ and see PDFcamp/PDFwriter - it looks like this is the least expensive way of converting html to pdf. If you are looking for more pro components then around at: www.pdfstore.com (Some of the prices out there are scare if you are a startup and dont have much money.)

To put the pdf in database just read the file in and use Convert.ToBase64String() and send it to the database.

Re: Convert HTML to PDF Stream into DB

Heath Stewart13-Jan-04 5:32

Heath Stewart

13-Jan-04 5:32

You could also - depending on the RDBMS - store the PDF as a binary stream, which some ADO.NET classes (like those in System.Data.SqlClient) support. IMO, you should store the PDF on the filesystem and either store the path in the DB or use the primary key as part of the filename, which is what we do in our flagship product.

Custom permissions

Hans Ruck13-Jan-04 1:43

Hans Ruck

13-Jan-04 1:43

I'm using the ".NET Configuration Tool" to change the properties of the permissions belongin' to various permission sets. This can be done using the "Properties" dialog available for any built-in permission.

Is there any way to provide such a dialog for a custom permission, a CodeAccessPermission-derived class? The default displays a message like "The Custom Permission is unrestricted", or an xml fragment Dead | X|

rechi

Re: Custom permissions

Heath Stewart13-Jan-04 5:30

Heath Stewart

13-Jan-04 5:30

The mscorcfg.dll assembly for the Microsoft .NET Framework Configuration snap-in is hard-coded to display views and property pages for the built-in permission classes and all the abstract classes are marked private. There is nothing in the .NET base class library for this either, unfortunately. You could take a look at the aforementioned assembly to see if there's any other hooks or interfaces, but it doesn't appear to have any.

Re: Custom permissions

Hans Ruck13-Jan-04 22:21

Hans Ruck

13-Jan-04 22:21

Thank you! Smile | :)

rechi

axwebbrowser excel mdicontainer

mylitziname12-Jan-04 22:28

mylitziname

12-Jan-04 22:28

If I open a form with a axwebbrowser-control in a mdi-container
and show an excel-sheet in the webcontrol, than close the form
and application, the excel-process leaves alive.
If I close the application without closing the form first
excel closes.

Help appreciated.

Litzi

Re: axwebbrowser excel mdicontainer

mylitziname12-Jan-04 23:24

mylitziname

12-Jan-04 23:24

Excel was closed when I used axWebBrowser1.Dispose()
in the closing event from the form

Litzi

Environment variable

cfl12-Jan-04 22:03

cfl

12-Jan-04 22:03

Hello Gurus,

I am using Environment.GetEnvironmentVariable() method to retreive a value from a an defined environment variable in a Win2k machine.

This method is able to get the value from a console application mode. However, if I run my application in a window service mode. It fail to get any value from the same defined environment variable.

Is there any setting I need to perform? Any suggestion, please advise. Thanks.

Re: Environment variable

mylitziname12-Jan-04 23:33

mylitziname

12-Jan-04 23:33

maybe your service runs in an other environment (other user)
try to get for example >ver<

Litzi

Re: Environment variable

Heath Stewart13-Jan-04 5:15

Heath Stewart

13-Jan-04 5:15

The environment variable has to be a system environment variable, or a user environment variable for the user that the service runs as. Adding environment variables from the command-line are also only valid for that instance of the command line, or any programs started from the command line. To configure persistent, global environment variables, go to the Advanced tab of your System Properties (right-click on My Computer and select Properties) and click the Environment Variables button (or similar). You'll see sections for both user and system environment variables there.

Re: Environment variable

cfl13-Jan-04 15:42

cfl

13-Jan-04 15:42

Hello all,

Thanks for your advise. The problem solved. Thanks.

.NET version dependent compilation

brain2cpu12-Jan-04 21:09

brain2cpu

12-Jan-04 21:09

is there something like:

#if theCompilerVersionIs1.0
using Microsoft.Data.Odbc;
#else
using System.Data.Odbc;

??

I have VS2002 and have to command line compile for 1.1 and it would be great not to change my code for this.

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.