C# Discussion Boards - CodeProject

Re: How did you learn to program?

Hamid_RT13-Dec-06 22:20

Hamid_RT

13-Dec-06 22:20

I think he/she want all views not only C# programmers or C++ programer Smile | :)

WhiteSky

Re: How did you learn to program?

SpartanSoft14-Dec-06 9:03

SpartanSoft

14-Dec-06 9:03

There are numerous ways to learn but I can let you know what worked best for me. I started going to Grad school for Masters in CS, I got about 1/2 way done and felt I had no real world experience for which I could change my occupation.

I found defining a problem and then coding to solve the problem to be the easiest way to learn. Come up with an idea and just start coding it. You will come across numerous issues but everything has been done before so the solution should be available through Google.

I found studying for certification also helps, gives you a goal to strive for.

Read a book like Code Complete before you start, pick a language, read up on the syntax on the web to gain a high level understanding, create a project idea, and code away.. Just my 2 cents

Christopher Pond
Innovative Technology Solutions
SpartanSoft.net.

Object Factories with Lazy Loading in C#

cebyrjoe213-Dec-06 10:46

cebyrjoe2

13-Dec-06 10:46

I'm looking for a lazy loading solution in c#.

The idea is, to have a kind of object factory, which will be responsible for creating my entity objects.
When a property of such an object is accesed and it is not yet loaded, the factory
(or a magic watcher) will be able to pause the execution flow for a while (maybe that step is not necessary)
load the missing data (don't know how to specify, from where to load that data----maybe via attributes) and
return to the flow.

My entity objects, do not have a possibility to load the missing data by themselves, because they
are only data containers having private members, which are accessible via public properties.
These objects need to be filled with their data from outside, and therefore many lazy loading solutions
won't work here.

Maybe anyone of you knows the solution for my problem?

Thank You in advance!

Greetz!
cyberjoe

Re: Object Factories with Lazy Loading in C#

Colin Angus Mackay13-Dec-06 11:22

Colin Angus Mackay

13-Dec-06 11:22

cebyrjoe2 wrote:
The idea is, to have a kind of object factory, which will be responsible for creating my entity objects.
When a property of such an object is accesed and it is not yet loaded, the factory
(or a magic watcher) will be able to pause the execution flow for a while (maybe that step is not necessary)
load the missing data (don't know how to specify, from where to load that data----maybe via attributes) and
return to the flow.

Have you considered using properties?

public class MyClass
{
    private bool isLazyLoaded;
    private string someData;
 
    public string SomeData
    {
        get
        {
            DoLazyLoadIfNecessary();
            return this.someData;
        }
    }
 
    private void DoLazyLoadIfNecessary()
    {
        if (!isLazyLoaded)
        {
            // Do what ever is necessary to get the values.
        } 
    }
}

Once you have this only the code that does the lazy load will access the lazy loaded fields directly. Everything else goes through the property.

cebyrjoe2 wrote:
My entity objects, do not have a possibility to load the missing data by themselves, because they
are only data containers having private members, which are accessible via public properties.
These objects need to be filled with their data from outside, and therefore many lazy loading solutions
won't work here.

I should have read the whole thing before typing out that example - Sod it, I've typed it now so I'm keeping it! Big Grin | :-D

Each object will need to know at least an ID so that it can go and request its data from a DAL or some such thing.

Many of my objects have lazy load functionality, when they are created all that is known about them is a corresponding database ID. For any lazy load solution to work some sort of identifier needs to be known.

Upcoming Scottish Developers events:
* Glasgow: Tell us what you want to see in 2007

My: Website | Blog | Photos

[Message Deleted]

R_L_H13-Dec-06 9:49

R_L_H

13-Dec-06 9:49

[Message Deleted]

Re: How do you programmatically restart a Service? (specifically SQL Server)

Colin Angus Mackay13-Dec-06 11:29

Colin Angus Mackay

13-Dec-06 11:29

Probably:

System.Diagnostics.Process.Start("NET STOP MSSQLSERVER");

System.Diagnostics.Process.Start("NET START MSSQLSERVER");

Upcoming Scottish Developers events:
* Glasgow: Tell us what you want to see in 2007

My: Website | Blog | Photos

Re: How do you programmatically restart a Service? (specifically SQL Server)

navyjax224-Dec-08 13:14

navyjax2

24-Dec-08 13:14

You can't do it that way, with Process.Start(" ~ DOS NET START/STOP ~ ");

You have to do it like this (assuming SQL Server is running on the same computer as your program):

string localComputer = Environment.MachineName.ToString();

// Stop MSSQLSERVER
ServiceController controller = new ServiceController();
controller.MachineName = localComputer;
controller.ServiceName = "MSSQLSERVER";
string status = controller.Status.ToString();
if (status == "Running")
{
// Stop the service
controller.Stop();
Console.WriteLine("MSSQLSERVER has been stopped.");
}

// Start MSSQLSERVER
controller.MachineName = localComputer;
controller.ServiceName = "MSSQLSERVER";
status = controller.Status.ToString();
if (status == "Stopped")
{
// Stop the service
controller.Start();
Console.WriteLine("MSSQLSERVER has been started.");
}

Also, make sure the service name is MSSQLSERVER in the Services console (Start -> Run -> services.msc). On named instances, this is not always the case.

-Tom

Re: How do you programmatically restart a Service? (specifically SQL Server)

Andy Brummer13-Dec-06 11:37

Andy Brummer

13-Dec-06 11:37

You can also use the ServiceController[^] class.

Using the GridView is like trying to explain to someone else how to move a third person's hands in order to tie your shoelaces for you.
-Chris Maunder

Resize row height in DataGrid (Pocket PC)?

george ivanov13-Dec-06 7:17

george ivanov

13-Dec-06 7:17

How to resize the row height in CF.Framework DataGrid control? For columns there is DataGridColumnStyle, but not the same for rows.
thanks.

win form datagridview sort by column

fmardani13-Dec-06 6:07

fmardani

13-Dec-06 6:07

Hi,
Currently I am using the _SelectionChanged event for the dataGridView control to get cell values for the selected row in the control.
Now I would like to order the coluomns by clicking on the header.
But I get an error if a column name is clicked on.
The error occurs on the following line inside _SelectionChanged event:

int rowNum = dataGridView1.CurrentCell.RowIndex;

Obviously at this stage there is no row selected because I have clicked on a column.

I basically would like the column order to work but the above scenario is preventing it.

Re: win form datagridview sort by column

Milky Way13-Dec-06 10:17

Milky Way

13-Dec-06 10:17

dataGridView1.CurrentCell returns null if no cell is selected.

Unable to Deserialize - [cannot find an Assembly ]

Eytukan13-Dec-06 5:48

Eytukan

13-Dec-06 5:48

ERROR:
Cannot find the assembly MyProject, Version=1.0.1123.4445, Culture=neutral, PublicKeyToken=null.
CODE :

<br />
bytes bs[];<-- Receives data from Socket<br />
BinaryFormatter formatter = new BinaryFormatter();<br />
MemoryStream memStream2 = new MemoryStream(bs);<br />
obj = (object)formatter.Deserialize(memStream2); //Looks like it's impossible :(<br />

When you send any data(anything object, like a DataTable) recognized by the framework, it doesn't throw this error.
But when I send my own structure, it throws this exception. Please help.

REFERENCE:
http://forums.microsoft.com/MSDN/ShowPost.aspx?PostID=961147&SiteID=1[^]

But the above thread talks about a web application. Mine is a windows application.
Also note, I'm new to .net Frown | :(

:Gong: 歡迎光臨吐西批 :Gong:

Re: Unable to Deserialize - [cannot find an Assembly ]

Karthik Kalyanasundaram13-Dec-06 6:03

Karthik Kalyanasundaram

13-Dec-06 6:03

You need to add reference to the assembly which define the type you are trying to deserialize in the receiving application.

Usually what we do is, we will find out the classes needed by the both communicating applications into a separate class library and reference to this library in both the applications. I think this will help you solve ur issue at hand.

Re: Unable to Deserialize - [cannot find an Assembly ]

Eytukan13-Dec-06 18:05

Eytukan

13-Dec-06 18:05

Thanks I'll try that.

:Gong: 歡迎光臨吐西批 :Gong:

DataTable.AcceptChanges

wasife13-Dec-06 5:19

wasife

13-Dec-06 5:19

Hi,
I am developing a project with C# in which i have a shared dataset. On many occasions, I need to delete tables from this dataset for which i call DataSet.Tables.Remove(Tablename). But I have found that this does not work perfectly. Since many times when i make the table with the same name in this dataset after deleting one, i think it contains some extra rows. Can anybody tell me the cause of the problem? Moreover should i call AcceptChanges on the removed table after removing it or it is removed automatically?

Regards,
Wasif Ehsan.

Re: DataTable.AcceptChanges

Andrew Rissing13-Dec-06 7:23

Andrew Rissing

13-Dec-06 7:23

When you call Remove() (and this applies to DataTables and DataRows), underneath the covers its essentially equivalent to calling Delete() and AcceptChanges(). So, you do not need to call AcceptChanges() when calling Remove().

As for your additional rows, I would try to track down in your debugger the source of those rows.

Writing to an access database with credentials

Beaumont113-Dec-06 4:28

Beaumont1

13-Dec-06 4:28

I am new to visual C# but I have written a program that will gather hardware and software information from a PC then write this info to a database on a server.

The problem is that I can run the program from my PC, but I want to run it from multiple PCs on the network and I don't know how to set up credentials so everyone can get to the database on the server.

Can this be written in the program?

Thanks in advance.

Re: Writing to an access database with credentials

led mike13-Dec-06 6:39

led mike

13-Dec-06 6:39

Have you looked through the many Database related articles here on Code Project or searched on MSDN for examples?

led mike

Re: Writing to an access database with credentials

Beaumont113-Dec-06 7:11

Beaumont1

13-Dec-06 7:11

Yes, I have and they have helped me quite a bit.

The only missing piece to this puzzle is the credential thing.

Can you help??

Thanks.

Re: Writing to an access database with credentials

led mike13-Dec-06 7:22

led mike

13-Dec-06 7:22

Beaumont1 wrote:
Can you help??

Maybe. Most of the Articles on Database developement here should discuss the login/password part of the database connection string. Is that what you are asking about? Be more specific about "credentials".

led mike

Re: Writing to an access database with credentials

Beaumont113-Dec-06 7:24

Beaumont1

13-Dec-06 7:24

Yes, you are correct. That's what I am looking for.

Thank you.

how to read from a ethernet connection

faladrim13-Dec-06 3:43

faladrim

13-Dec-06 3:43

hi,
i want to read from a microprocessor that is directly connected with a croseover ethernet cable
but i dont know how.
on the processor site is everyting in order, i am able to ping to my pc and from my pc using Dos command.
how do i set up the comm using c#??
i know it has something to do with Tcpclient but there i need a portnumber wich i don't know, i don't need acces to the internet.
can anybody help plzz
thx

Class inheritance and interfaces

Dario Solera13-Dec-06 3:39

Dario Solera

13-Dec-06 3:39

A strange question, but I couldn't find anything specific and just trying is not the solution.

Suppose I have two interfaces, lets call them IMyInterface1 an IMyInterface2.
They share a couple of methods (they're identical), but I don't want to use a shared interface with just those methods and then inherit my two interfaces from that one.

Now I have two classes (MyClass1 and MyClass2), each one implementing one of the two interfaces. Both of them must inherit from another class (MarshalByRefObject).

The question is: can I extract a class (MyCommonClass) implementing the common methods of the interfaces, inherit from that class and implement the two classes just implementing the remaining methods? This way MyCommonClass should inherit from MarshalByRefObject, then MyClass1 and MyClass2 should inherit from MyCommonClass.

Are the two interfaces correctly implemented in the compiler's opinion?

Brief pseudo-code:

class MyCommonClass : MarshalByRefObject; // Implementing common methods of IMyInterface1 and IMyInterface2
class MyClass1 : MyCommonClass, IMyInterface1; // Implementing the remaining methods of IMyInterface1
class MyClass2 : MyCommonClass, IMyInterface2; // Implementing the remaining methods of IMyInterface2

Thanks for any help.

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Re: Class inheritance and interfaces

J4amieC13-Dec-06 3:45

J4amieC

13-Dec-06 3:45

Dario Solera wrote:
Are the two interfaces correctly implemented

Short answer: Yes

Bear in mind that any reference to MyCommonClass will not be able to act as iMyInterface1 or IMyInterface2 - only references to either of the MyClass1 or MyClass2

---

How to get answers to your questions[^]

Re: Class inheritance and interfaces

Dario Solera13-Dec-06 3:52

Dario Solera

13-Dec-06 3:52

J4amieC wrote:
Bear in mind that any reference to MyCommonClass will not be able to act as iMyInterface1 or IMyInterface2

Yes, that's clear.
Thanks for your reply. Rose | [Rose]

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