OOP question: correct obect composition in C# - C# Discussion Boards

25-Jun-08 1:36

Please don't ask twice.

Have you tried google ?

Christian Graus

Please read this if you don't understand the answer I've given you

"also I don't think "TranslateOneToTwoBillion OneHundredAndFortySevenMillion FourHundredAndEightyThreeThousand SixHundredAndFortySeven()" is a very good choice for a function name" - SpacixOne ( offering help to someone who really needed it ) ( spaces added for the benefit of people running at < 1280x1024 )

Re: cystal report

leppie25-Jun-08 2:03

crystal report - very urgent

25-Jun-08 2:03

And somehow you cannot do this in the designer? D'Oh! | :doh:

xacc.ide - now with TabsToSpaces support
IronScheme - 1.0 alpha 4a out now (29 May 2008)

Re: cystal report

Verghese25-Jun-08 3:21

Verghese

25-Jun-08 3:21

can u be more specific with what u r looking for ???

cse.vidhya25-Jun-08 0:53

cse.vidhya

25-Jun-08 0:53

hi i am using crystal report in windows appliction

i am getting output from my database as...

data data data
data data data

data data data
data data data

tell me how to extend height between these datas in crystal repor

regards,
vidhya.s

MustUnderstand WCF connecting to Java web service [modified]

Simon Lime25-Jun-08 0:52

Simon Lime

25-Jun-08 0:52

Is there a simple way of setting MustUnderstand in WCF?

I have a project which uses WSE to connect to a java web service. In order to get it working I had to change the mustunderstand property on the client which was a simple one line if I recall
e.g.
requestContext.Security.MustUnderstand = false

How do I achieve the same using WCF?

modified on Wednesday, June 25, 2008 9:33 AM

Re: MustUnderstand WCF connecting to Java web service

Simon Lime7-Jul-08 1:06

Simon Lime

7-Jul-08 1:06

Could not find a straightforward way of doing this client side.

To fix this I had to ammend the java class to add "http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd" to the list of understood headers.

OOP question: correct obect composition in C#

Metal7625-Jun-08 0:41

Metal76

25-Jun-08 0:41

Hi, I have a question on correct usage of object composition. This is the situation I'm facing:

class Address
{    
    // An address is composed of several fields
    private byte _FieldA;
    private byte _FieldB;
    private byte _FieldC;

    // Each field is exposed with a public property
    public byte FieldA
    {
        set { _FieldA = value; }
        get { return _FieldA; }
    }
    // ... and so on for the other fields

    // I have several useful public methods for address manipulation
    public void SetAddress (byte fieldA, byte fieldB, byte fieldC);
    public void DoStuff(...)
    public void DoOtherStuff(...)
    ...
}


class Message
{    
    // A message contains 2 addresses
    public Address SourceAddress = new Address();
    public Address DestAddress = new Address();
}

A client which instantiates a message should only be able to access the address fields and to invoke SetAddress().

By declaring SourceAddress and DestAddress objects as public, I can write things like message.SourceAddress.FieldA, message.DestAddress.SetAddress(), with no need for additional code. However, I also expose other methods like DoStuff() etc, which a message should not be able to call.

On the other hand, if I declare SourceAddress and DestAddress as private, I can control what I expose to the client but I'm also forced to add a lot of code: public properties and methods like SourceAddressFieldA, SourceAddressFieldB, SetSourceAddress(), all duplicated for DestAddress... this means a lot of code duplication, and less flexibility (imagine if I have to add other Address fields to Message...).

Is there a "sweet spot"? Is there a correct (or better, preferred) way to expose the behaviour of child objects in C#?

Regards,
Andrea

Re: OOP question: correct obect composition in C#

Christian Graus25-Jun-08 0:49

25-Jun-08 0:49

I think the best way is to make Address use an interface which defines the methods you want the Message to have access to. Then do public IPublicAddress SourceAddress = new Address(); This means that the Message class can only access the methods you want it to.

how i can run a dll

wasimsharp25-Jun-08 0:22

wasimsharp

25-Jun-08 0:22

hi i created a dll in which i create a wizard
plz any body can tell me how i can run this dll using C# code
so that when dll execute the Wizard starts

wasim khan

Christian Graus25-Jun-08 0:23

25-Jun-08 0:23

You can't run a dll. You write an app that imports the dll, and calls methods in it.

wasimsharp25-Jun-08 0:37

wasimsharp

25-Jun-08 0:37

hi Chris
then how my application run the dll that is downloaded by the System Configurator

wasim khan

Christian Graus25-Jun-08 0:45

25-Jun-08 0:45

Your app can probe any dll via reflection, or it can be built to import a dll, then it can call it directly.

Well, so long as it's a .NET dll. otherwise, you can p/invoke or call via COM, but you can't reflect, so you'd need to know about it at compile time.

Re: treeview and mdichild

Mbah Dhaim25-Jun-08 3:43

Mbah Dhaim

25-Jun-08 3:43

use unmanaged code to access your dll and use managed or direct call to your method
example

using System;
using System.Runtime.InteropServices

//this class is unmanaged code
class UnmanagedAccessDll
{
//use to import your method in your dll
  [DllImport("myDll.dll")]
public static extern void StartWizard([required parameters if any]);
}
//sample managed class code
public ManagedAccessDll
{
  public void Startwizard([required parameters if any]){
UnmanagedAccessDll.Startwizard([required parameters if any]);
}
} 

or you can call directly in your code

...
UnmanagedAccessDll.Startwizard([required parameters if any]);
...

treeview and mdichild

ginji2025-Jun-08 0:06

ginji20

25-Jun-08 0:06

can someone know how to put a code on a treeview node??

where can i find the mdichild form..
there is no mdi child form on the when i clicked project then add form..

ginji

DaveyM6925-Jun-08 7:56

DaveyM69

25-Jun-08 7:56

Do you mean how to create a TreeNode in code and add it to a TreeView? If so:

// This method has many options - check MSDN
TreeNode node = new TreeNode("Node Text"); 
treeView1.Nodes.Add(node);

MDI children are just normal forms which is why there's no automatic MDIChildForm option.
Set the parent form's IsMdiContainer property to true, and after you instanciate the child form, set it's MdiParent property to the parent form. i.e.

Form2 form2 = new Form2();
form2.MdiParent = this;
form2.Show();

Dave

Re: treeview and mdichild [modified]

ginji2025-Jun-08 15:15

ginji20

25-Jun-08 15:15

i mean how to put a code in a node for example if i click node1 another form opens then if i click node2 the form is disabled...

mdichild
thanks i created a mdi child form can i also how can i close the mdichild form and goes back to the mdiparent because if i hide the mdichild the mdiparent also hides.

modified on Wednesday, June 25, 2008 9:27 PM

Interfaces and Casting - I'm struggling.

stovesy24-Jun-08 23:57

24-Jun-08 23:57

A little background.

I'm playing with BusinessObjects and Factory(s) which contain collections of BusinessObjects.

My business objects all derive from a BusinessObjectBase class.
I have an IBusinessObjectBase interface, which the BusinessObjectBase implements.

My factory objects all derive from a FactoryBase class.
The FactoryBase class is generic (FactoryBase<T> where T : IBusinessObjectBase)
I have an IFactoryBase interface, which the FactoryBase impliments.
public interface IFactoryBase<T> where T : IBusinessObjectBase

Everything works fine (I'm not sure if the model is a little simplistic maybe)

Now.
I'm wanting to create a status bar, which displays a few properties from the current BusinessObject, and the currenct Factory (Like data errors, read only info etc.).
So I created a test to see how to go about this, but encountered a problem.

customerFactory cFact = new customerFactory();

if (cFact is IFactoryBase<IBusinessObjectBase> ) TestContext.WriteLine("IFactoryBase supported");
if (cFact is IComponent) TestContext.WriteLine("IComponent supported");
if (((IFactoryBase<IBusinessObjectBase> )cFact).IsClean) TestContext.WriteLine("Factory is clean");

customerFactory is derived from FactoryBase, and does indeed support the IFactoryBase interface.
public class customerFactory : FactoryBase<customer>
The customer object is derived from BusinessObjectBase, and supports IBusinessObjectBase

The first line, fails even though my Factory does support the interface.
The second line succeeds (IComponent is indeed supported)
And the third line fails to cast.

Many thanks.

leppie25-Jun-08 2:11

25-Jun-08 2:11

stovesy wrote:
My factory objects all derive from a FactoryBase class.
The FactoryBase class is generic (FactoryBase<t> where T : IBusinessObjectBase)
I have an IFactoryBase interface, which the FactoryBase impliments.
public interface IFactoryBase<t> where T : IBusinessObjectBase

You cant just implement the interface and expect it to magically become one!

FactoryBase should be declared as:

class FactoryBase<t> : IFactoryBase<t> where T : IBusinessObjectBase ...</t></t>

xacc.ide - now with TabsToSpaces support
IronScheme - 1.0 alpha 4a out now (29 May 2008)

stovesy25-Jun-08 2:27

25-Jun-08 2:27

As stated above, the FactoryBase class, does implement the IFactoryBase interface, I've just not show that in code.

Cheers.

leppie25-Jun-08 4:51

25-Jun-08 4:51

stovesy wrote:
I've just not show that in code.

Then dont complain at my answer. If it indeed is a FactoryBase derived object it has to be IFactoryBase then, and you have made a mistake somewhere.

xacc.ide - now with TabsToSpaces support
IronScheme - 1.0 alpha 4a out now (29 May 2008)

stovesy25-Jun-08 5:33

25-Jun-08 5:33

You misunderstand - I'm not complaining about your answer, just clarifying things.

Thanks for your interest.

leppie25-Jun-08 4:54

25-Jun-08 4:54

stovesy wrote:
IFactoryBase<ibusinessobjectbase>

IFactoryBase<customer> is needed then.

xacc.ide - now with TabsToSpaces support
IronScheme - 1.0 alpha 4a out now (29 May 2008)

stovesy25-Jun-08 5:36

25-Jun-08 5:36

We're getting to the crux of the matter.

What you suggest does work, but I don't know the type of the generic class, only that it derives from IBusinessObjectBase

So when I try ...(customerFactory is IFactoryBase<ibusinessobjectbase>).... it fails.

Thanks for your time

leppie25-Jun-08 5:43