Re: Use interface to force inheritance? - C# Discussion Boards

Re: Trying to call a c++ function in C# code using PInvoke

Colin Angus Mackay17-Jun-09 21:39

Colin Angus Mackay

17-Jun-09 21:39

siddy17 wrote:
at the C++ end it becomes bin\\debug\\abc.txt

Are you sure that's not just the debugger representing the string as a C# string?

Have you viewed the string using the text visualiser instead to be absolutely sure it is really containing the double slashes? (Hover over the string variable, you'll get a little arrow in the tooltip which will offer you some visualisers, choose the Text Visualiser)

Re: Trying to call a c++ function in C# code using PInvoke

siddy1717-Jun-09 23:00

siddy17

17-Jun-09 23:00

Hi I have used Text visualizer.

May be I was not very precise. In C#, I have to use '\' as an escape character. Hence If I pass a filename as "D:\\ABC.txt", the function in C++ does not take the path as is, it implcitly appends two more '\'s as escape characters (one for each '\' in the filename) and hence cannot
find the file.

The problem lies at at the C++ end.

Thanks,
Siddy

Re: Trying to call a c++ function in C# code using PInvoke

dan!sh 17-Jun-09 23:19

dan!sh

17-Jun-09 23:19

What if you send the path as @"d:\abc.txt"?

जय हिंद

Use interface to force inheritance?

Tobias Norlund17-Jun-09 21:13

Tobias Norlund

17-Jun-09 21:13

Hi!

I have a simple question.
With an interface I can force the classes that implements it, to implement methods and properties defined in the interface. But am I able to force the classes to inherit som other class, with an interface?

Thanks!

Re: Use interface to force inheritance?

Colin Angus Mackay17-Jun-09 21:35

Colin Angus Mackay

17-Jun-09 21:35

No.

What you could do is make the class "inherit" the interface and then you inherit the class. If it is an abstract class I would imagine (because I've not tried it) that you could delay the implementation of the interface until it got to the class that inherits the abstract class.

Re: Use interface to force inheritance?

dan!sh 17-Jun-09 21:43

dan!sh

17-Jun-09 21:43

AFAIK no.
Why do you want to do a forced inheritance?

जय हिंद

Re: Use interface to force inheritance?

Tobias Norlund18-Jun-09 1:40

Tobias Norlund

18-Jun-09 1:40

I want my derived classes both to have the functionality from the System.Windows.Forms.UserControl and have to implement the methods and properties described in my IGroup interface.

Re: Use interface to force inheritance?

Mirko198017-Jun-09 22:01

Mirko1980

17-Jun-09 22:01

Using an interface, you can only "force" a class to inherit only other interfaces.
If you want to force a class to inherit some other class, you can create, as others have said, an abstract class thats derives from the class you want to force inheritance. Keep in mind, though, that in c#, unlike interfaces, a class cannot directly inherit from multiple classe.

Re: Use interface to force inheritance?

Tobias Norlund18-Jun-09 1:54

Tobias Norlund

18-Jun-09 1:54

Yeah, that will probably be my solution. I now use an abstract class instead of the interface!

MS-Access problem with Vista - C#.net Windows Application

shw 23417-Jun-09 21:10

shw 234

17-Jun-09 21:10

Hi,

I keep getting the following problem only on Vista. My application is working fine on XP. Need your expertise to advise me on what went wrong.

//Code fragement
GetRecords() //from Access Database
ComputeValuesforRecords() //I am modifying the record values in dataset
DisplayRecords() //I am showing them in Grid

---

This code fragement always shows an error message "There is no row at position 0' when ComputeValuesforRecords() is called. This happens only on Vista. I am not sure why this is happening. Any clues?

Thanks

Re: MS-Access problem with Vista - C#.net Windows Application

EliottA18-Jun-09 3:30

EliottA

18-Jun-09 3:30

Without knowing anything other then your method names, did you include your access database file with your project? Did you hardcode the path to your access file, if so is that path still valid under vista?

Check out the CodeProject forum Guidelines[^]
The original soapbox 1.0 is back![^]

Re: MS-Access problem with Vista - C#.net Windows Application

OriginalGriff18-Jun-09 3:43

OriginalGriff

18-Jun-09 3:43

EliottA wrote:
is that path still valid under vista?

And do you have the necessary access permissions?

No trees were harmed in the sending of this message; however, a significant number of electrons were slightly inconvenienced.

This message is made of fully recyclable Zeros and Ones

Open URL

Nafiseh Salmani17-Jun-09 20:58

Nafiseh Salmani

17-Jun-09 20:58

I want to access HTML code of sites like www.yahoo.com through C# application to collect some info ! how can i do this?!

thanks

Re: Open URL

stancrm17-Jun-09 21:02

stancrm

17-Jun-09 21:02

http://msdn.microsoft.com/en-us/library/system.net.httpwebrequest.aspx[^]

Date format

strings17-Jun-09 20:46

strings

17-Jun-09 20:46

I am using Mysql as my database.
i insert the date in the format DateTime.Now.ToString("dd/MM/yyyy") but the strange thing is its gets entered in dd-MM-yyyy format.
EVen if i manaually entered the date in database in dd/MM/yyyy and retrive the value from database , its get the format as dd-MM-yyyy.
where is the prob???

Re: Date format

Ashfield17-Jun-09 20:58

Ashfield

17-Jun-09 20:58

There is no problem. Databases don't store the date in a specific format - Don't know about MySql, but SQL Server and Sybase store it as a number, its up to your code to display it how you want. There will be a default format from the database (usually defined at server level) and its up to you to format it how you want.

Bob
Ashfield Consultants Ltd
Proud to be a 2009 Code Project MVP

Re: Date format

strings17-Jun-09 21:17

strings

17-Jun-09 21:17

Thks for ur reply, but it didn't solved my prob.
Interesting thing is date format dd/MM/yyyy in getting inserted correctly on my PC.
but when i deployed at client location its gets entered as dd-MM-yyyy format
coloum Type is varchar 50.

Re: Date format

stancrm17-Jun-09 21:56

stancrm

17-Jun-09 21:56

I think it's a localization problem.
Save the date in MySql Date format, not in string.

Re: Date format

Tom Deketelaere17-Jun-09 22:46

Tom Deketelaere

17-Jun-09 22:46

strings wrote:
coloum Type is varchar 50

There is your problem

strings wrote:
date format dd/MM/yyyy in getting inserted correctly on my PC.
but when i deployed at client location its gets entered as dd-MM-yyyy format

When displaying a date (and inserting it into db in a varchar column) without specific formating it will display the way the date settings are set in Windows.

First of all you should use a date column type.

Then you can either instruct your client on how to change his OS settings (not recommended)
or do a format of the date.

Re: Date format

Ashfield18-Jun-09 1:20

Ashfield

18-Jun-09 1:20

strings wrote:
coloum Type is varchar 50.

If you had said that in the first place it would have been obvious, its a localisation issue nothing to do with sql. Use a proper datatype and your problem will be solved.

Bob
Ashfield Consultants Ltd
Proud to be a 2009 Code Project MVP

Re: Date format

stancrm17-Jun-09 21:05

stancrm

17-Jun-09 21:05

http://www.plus2net.com/sql_tutorial/date-inserting.php[^]

Query Regarding Open Source DotNet Based Desktop Sharing Apps like citrix??

Tridip Bhattacharjee17-Jun-09 20:44

Tridip Bhattacharjee

17-Jun-09 20:44

i search google for Open Source DotNet Based Desktop Sharing apps but did not find anything like that so please if anyone knows that there is such open source dotnet based Desktop Sharing apps then please inform me.....i will be highly obliged.

tbhattacharjee

Query Regarding Open Source DotNet Based Sql Database Synchronization??

Tridip Bhattacharjee17-Jun-09 20:42

Tridip Bhattacharjee

17-Jun-09 20:42

i search google for Open Source DotNet Based Sql Database Synchronization apps but did not find anything like that so please if anyone knows that there is such open source dotnet based apps then please inform me.....i will be highly obliged.

tbhattacharjee

Privew of Webcam

S K Y17-Jun-09 20:07

S K Y

17-Jun-09 20:07

i can connect to webcam....
how can i show preview of webcam in picturebox...???

private void btnDecode_Click_1(object sender, EventArgs e)
        {           
            try
            {
                DeviceManager manager = new DeviceManagerClass();
                Device d = null;
                foreach (DeviceInfo info in manager.DeviceInfos)
                {
                    d = info.Connect();
                    
                }
                Item item = d.ExecuteCommand(CommandID.wiaCommandTakePicture);
                foreach (string format in item.Formats)
                {
                    WIA.ImageFile imagefile = item.Transfer(format) as WIA.ImageFile;
                    imagefile.SaveFile("d:\\test2.JPG");

A S E L A

Re: Privew of Webcam

Christian Graus17-Jun-09 21:52

Christian Graus

17-Jun-09 21:52

Well, you could create a BItmap from test2.jpg, and assign it to a picture box ?

Christian Graus

Driven to the arms of OSX by Vista.

"! i don't exactly like or do programming and it only gives me a headache." - spotted in VB forums.

I can do things with my brain that I can't even google. I can flex the front part of my brain instantly anytime I want. It can be exhausting and it even causes me vision problems for some reason. - CaptainSeeSharp

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