C# Discussion Boards - CodeProject

Re: How to create an combobox inside IDE's property editor ?

14-Feb-04 8:34

I have an ArrayList of objects (all the same type). All of these objects (classes) contain a string property Name. I also have a variable CurrentMyObject that shows witch MyObject to use currently (there are a lot of MyObject instances, try to think of MyObject as of an adapter).

<br />
<br />
private MyObject CurrentMyObject;<br />
private ArrayList MyObjectsList = new ArrayList();<br />
public class MyObject<br />
{<br />
   protected string name;<br />
   public string Name {...}<br />
}<br />
<br />
...<br />
string something = CurrentMyObject.Name;<br />
...<br />

Is it possible to let the user set the CurrentMyObject from a dropdown meny in Property Editor inside IDE (design time)? I mean to create a list (maybe an array) of each MyObject instance's name string and the set the CurrentMyObject by the name property. There's no problem with setting the CurrentMyObject by a name, the problem is how to create the combobox inside Propert Editor to let the user to do that inside IDE (VS.NET property editor) ...

Regards, Desmond

Heath Stewart14-Feb-04 9:24

Re: How to create an combobox inside IDE's property editor ?

14-Feb-04 9:24

You need to attach a TypeConverter via the TypeConverterAttribute that returns true for TypeConverter.GetStandardValueSupported (there are other ways as well). Read about the classes in the System.ComponentModel namespace, and read the section in the .NET Framework SDK, Enhancing Design-time Support[^]. Besides talking about TypeConverters, there are a great many other design-time features you can exploit that are discussed.

BTW, many Types (like Enums) already have TypeConverters associated with the Type, such that any property of that Type uses the TypeConverter unless the property is attributed using a TypeConverterAttribute that specifies a different TypeConverter to use.

Microsoft MVP, Visual C#
My Articles

Andres Coder14-Feb-04 9:46

Re: How to create an combobox inside IDE's property editor ?

14-Feb-04 9:46

Thanks, unfortunately I cannot use enums (unless there is a way to construct a dynamic enum at runtime). It's a lot of reading I have to do (at msdn).

Anyway, could you please provide me with an example with this case here ?

Heath Stewart15-Feb-04 5:43

Re: How to create an combobox inside IDE's property editor ?

15-Feb-04 5:43

I didn't tell you to use enums. Just that enums have a default TypeConverter associated with them. TypeConverter.GetStandardValuesSupported and TypeConverter.GetStandardValues aren't just for display enum members either. Lots of properties use this, whether it's displaying the names of controls (of a particular Type, perhaps) by getting the container and enumerating the controls, or anything like that.

If you read the documentation I gave you links for, there are plenty of examples in the topics. Besides, there's few methods to implement and they should be obvious how to use.

Microsoft MVP, Visual C#
My Articles

Andres Coder15-Feb-04 7:21

Re: How to create an combobox inside IDE's property editor ?

15-Feb-04 7:21

Thanks, I will. I sometimes have trouble understanding english, it's really not my native language, so this should explane the misunderstandings.

Heath Stewart16-Feb-04 4:34

Re: How to create an combobox inside IDE's property editor ?

16-Feb-04 4:34

Sorry. You could've fooled me, though! Your grammar is excellent - much better than most American's I've seen.

Microsoft MVP, Visual C#
My Articles

Andres Coder16-Feb-04 7:23

16-Feb-04 7:23

That's because I try to write grammatically correctly as possible (I try to make use of what I've learned). I'm actually from Estonia (Europe, next to Finland over the Baltic sea).

Timezone: Setting?

CyMad14-Feb-04 3:55

14-Feb-04 3:55

I am currently involved in a barcode scanning project using .NET compact framework & C#. I need to programatically be able to set the timezone of the device when the application starts. The MSDN documentation only seems to have a gettimezone method in the timezone class & no way of setting it Confused | :confused:

. Is there away to set this?

Any help would be much appreciated Cry | :((

CyMad
CF Developer

Mazdak14-Feb-04 4:10

14-Feb-04 4:10

I don't know any .net way too, but you can use SetTimeZoneInformation() win32 function.

Mazy

You're face to face,
With the man who sold the world - David Bowie

CyMad16-Feb-04 7:46

16-Feb-04 7:46

Thanks for that, would it be possible for you to provide an example of its use as I am a newbie to p/invoke?

CyMad
CF Developer

Mazdak16-Feb-04 8:41

16-Feb-04 8:41

Search for DllImport in this site and MSDN and you will get lots of sample. Smile | :)

Mazy

You're face to face,
With the man who sold the world - David Bowie

CyMad17-Feb-04 3:45

17-Feb-04 3:45

Thanks for your help?

All working now Big Grin | :-D

CyMad
CF Developer

Heath Stewart14-Feb-04 9:28

14-Feb-04 9:28

.NET is a high-level framework (seemingly till "Longhorn") and is not intended for such use (just like you can't set the system time or display characters, etc.). Mazdak's right, you'll have to P/Invoke SetTimeZoneInformation (see the DllImportAttribute), which is supported by Windows CE 1.0 and later (which means Pocket PC 2002 and 2003 support it).

Microsoft MVP, Visual C#
My Articles

Thanks for help:-D

CyMad17-Feb-04 5:52

Best Practice: Internet Connection?

17-Feb-04 5:52

Many thanks for help provided Big Grin | :-D

In my search for help I came accross a usefull site which contains a near complete win32 api library with source code written in C#

OpenNetCF

CyMad
CF Developer

Troy G14-Feb-04 3:18

Troy G

14-Feb-04 3:18

Hello all,

I would like to know what the best practice is for testing if a program has a valid internet connection. I have a function which tells me if the program is connected or not but I would hate to have to call this everytime I need to perform some operation.

What I am looking for is something like in Messenger when you lose an internet connection it notifies you. Am I limited to a timer that constantly checks for the internet connection or is there some way my app can receive a message when a connection gets unplugged or something similar.

Does this make any sense? Any help is greatly appreciated.

Smile | :)

Thanks,
Troy G

Mazdak14-Feb-04 4:02

14-Feb-04 4:02

Yes, you have to check it in a timer or thread. Whats the problem with that?

Mazy

You're face to face,
With the man who sold the world - David Bowie

Troy G14-Feb-04 4:06

Troy G

14-Feb-04 4:06

Mazy,

No problem. Just thought there may be something else I could do that would be easier on resources.

Thanks for responding,
Troy

visiontec14-Feb-04 8:34

visiontec

14-Feb-04 8:34

Hi there
I have the same problem as yours
but u have at least made a function to get yr work done.
I couldnt even do that !
can u plz pass a copy of that function to me?
Thanks

VisionTec

Nick Parker14-Feb-04 9:29

Nick Parker

14-Feb-04 9:29

visiontec wrote:
can u plz pass a copy of that function to me?

Just P/Invoke InternetGetConnectedState[^] and call it when your Tick event fires from your timer.

- Nick Parker
My Blog

something wrong with my ADO.net

Troy G14-Feb-04 12:46

Troy G

14-Feb-04 12:46

This is what I use, there are a bunch of them...

//Creating the extern function...
[DllImport("wininet.dll")]
private extern static bool InternetGetConnectedState(out int Description, int ReservedValue);

//Creating a function that uses the API function...
public static bool IsConnectedToInternet()
{

int Desc ;
return InternetGetConnectedState(out Desc, 0);

}

ASGill14-Feb-04 2:53

ASGill

14-Feb-04 2:53

im using ADO.Net to connect to my database(im using Visual Studio .NET 2003) whenever i add the namespace System.Data now when i add this
i dont have System.Data.OleDb in the list when intelisense pops up...is something wrong?...so im using System.Data.SqlClient...can this work with SQL SERVER 7.0 databases...i read in a book(C# How To Program by Deitel & Deitel) that System.Data.SqlClient only for SQL SERVER 2000 databases

oh yeah can i know any WEB SITE where i can get a really good explaination abt Manipulating a Database.(ADDING,INSERTING,DELETING,MODIFYING...ETC)

Arvinder Gill

Re: something wrong with my ADO.net

Mazdak14-Feb-04 4:05

14-Feb-04 4:05

ASGill wrote:
so im using System.Data.SqlClient...can this work with SQL SERVER 7.0 databases

Yes, it works with SQLServer 7 and later.

ASGill wrote:
i read in a book(C# How To Program by Deitel & Deitel) that System.Data.SqlClient only for SQL SERVER 2000 databases

Nope.

ASGill wrote:
i dont have System.Data.OleDb in the list when intelisense pops up...is something wrong

Go to project references and add System.Data namespace.

Mazy

You're face to face,
With the man who sold the world - David Bowie

ReadFile error

Member 57829113-Feb-04 21:30

Member 578291

13-Feb-04 21:30

hi!
what should i do when i make use of the ReadFile function from the Packet Analyzer program(by floack), and i get an error saying that "a device attached to the system is not functioning". I am trying to integrate a ping feature to that program when i would send a ping request and wait for its reply. i am able to sucessfully send the request, however when i use the ReadFile to listen to the same port, i get the error stated above. can anyone help me with this problem?
Thanks!

Lots

Re: ReadFile error

Heath Stewart14-Feb-04 9:17