Anyone knows the C# Equivalent

  • Thread starter Thread starter alee via DotNetMonster.com
  • Start date Start date
A

alee via DotNetMonster.com

Hello,

I am trying to convert a program from Microsoft VB.NET team:

http://blogs.msdn.com/vbteam/archive/2005/04/14/TableAdaptersAndObjects.aspx

I am having a hard time converting the following two sections. Anyone knows
the C# equivalent?


- oringial VB.NET code from VB Team:
Public Sub AcceptChanges()

For Each item As T In Me.Items

item.ObjectState = ObjectState.Unchanged

Next

DeletedRows.Clear()

End Sub

- my approach:
public void AcceptChanges()
{
foreach (T item in this.Items)
{
item.ObjectState = ObjectState.Unchanged;
}
DeletedRows.Clear();
}
- Visusal Studio error: 'T' does not contain a definition for 'ObjectState'

2. Original code from VB team:

Dim txScope As New System.Transactions.TransactionScope

Using txScope
...
end using

- my approach:

using txScope
{
...
}
- Visual Studio:

Syntax error, '(' expected

Best regards,

Alan L.
 
- my approach:
public void AcceptChanges()
{
foreach (T item in this.Items)
{
item.ObjectState = ObjectState.Unchanged;
}
DeletedRows.Clear();
}
- Visusal Studio error: 'T' does not contain a definition for 'ObjectState'
Click to expand...

What is your definition for "T"? I am assuming this article is using
it as a generic object, meaning you need to create it and what it is
supposed to be; in this case, give it a property of "ObjectState".
Read the article to figure out what the expectations of the object are
(namely, what it is supposed to be based on).

- my approach:

using txScope
{
...
}
- Visual Studio:

Syntax error, '(' expected
Click to expand...

This is an issue of scope. The proper syntax is:

using (txScope)
{
....
}
 
alee said:
- Visusal Studio error: 'T' does not contain a definition for 'ObjectState'
Click to expand...

C# is case sensetive while VB is not. Have you checked the exact name,
so it isn't for example "objectState"?
- my approach:

using txScope
{
...
}
- Visual Studio:

Syntax error, '(' expected
Click to expand...

using (txScope) {
...
}
 
Lucas,

Thanks for your suggestions. The using syntax works fine now.

However, I have tried several method to define the following VB.NET
equivalence without any luck.

VB.NET

Public MustInherit Class BaseList(Of T As BaseObject) Inherits BindingList(Of
T)

C# - tried

public abstract class BaseList<T as BaseObject> : BindingList<T>
public abstract class BaseList<T:BaseObject> : BindingList<T>

I just want to the generic T to inherit properties defined in BaseObject.

Cheers,

Alan L.




- my approach:
public void AcceptChanges()
Click to expand...
[quoted text clipped - 6 lines]
}
- Visusal Studio error: 'T' does not contain a definition for 'ObjectState'
Click to expand...

What is your definition for "T"? I am assuming this article is using
it as a generic object, meaning you need to create it and what it is
supposed to be; in this case, give it a property of "ObjectState".
Read the article to figure out what the expectations of the object are
(namely, what it is supposed to be based on).
- my approach:
Click to expand...
[quoted text clipped - 5 lines]
Syntax error, '(' expected
Click to expand...

This is an issue of scope. The proper syntax is:

using (txScope)
{
....
}
Click to expand...
 
Hi Goran,

Thanks. The using syntax works, but I still have problem converting the
definition
for the generic T. I

public abstract class BaseList<T of BaseObject> : BindingList<T>

- I want the generic key argument inherits properties defined in BaseObject.

Originaal VB.NET syntax is:

Public MustInherit Class BaseList(Of T As BaseObject) Inherits BindingList(Of
T)

Cheers,

Alan L.


Göran Andersson said:
- Visusal Studio error: 'T' does not contain a definition for 'ObjectState'
Click to expand...

C# is case sensetive while VB is not. Have you checked the exact name,
so it isn't for example "objectState"?
- my approach:
Click to expand...
[quoted text clipped - 5 lines]
Syntax error, '(' expected
Click to expand...

using (txScope) {
...
}
Click to expand...
 
Hello,

I am trying to convert a program from Microsoft VB.NET team:

http://blogs.msdn.com/vbteam/archive/2005/04/14/TableAdaptersAndObjec...

I am having a hard time converting the following two sections. Anyone knows
the C# equivalent?

- oringial VB.NET code from VB Team:
Public Sub AcceptChanges()

For Each item As T In Me.Items

item.ObjectState = ObjectState.Unchanged

Next

DeletedRows.Clear()

End Sub

- my approach:
public void AcceptChanges()
{
foreach (T item in this.Items)
{
item.ObjectState = ObjectState.Unchanged;
}
DeletedRows.Clear();
}
- Visusal Studio error: 'T' does not contain a definition for 'ObjectState'

2. Original code from VB team:

Dim txScope As New System.Transactions.TransactionScope

Using txScope
...
end using

- my approach:

using txScope
{
...
}
- Visual Studio:

Syntax error, '(' expected

Best regards,

Alan L.
Click to expand...

Hi,

The first equivalent:
Well, you are trying to use a class (T) that is supposed to have an
ObjectState property. However, this should be explicitly declared
using the "where" keyword in C#. You need to change the class
definition to something as follows:

public class MyClass<T> where T: BizObjBase

this tells the compiler that T is of type BizObjBase...

The second equivalent:
using (TransactionScope txScope = new TransactionScope())
{
//do whatever you need with txScope
}

HTH,
Mehdi
 
If you have a base class for all objects that the class handles, then
you don't need to use generics at all in your class. Just use the base
class when you inherit the BindingList.

public abstract class BaseList : BindingList<BaseObject>

Now your BaseList is a BindingList that handles any object that inherits
from BaseObject.

In your method that loops the items, just reference them as BaseObject:

public void AcceptChanges() {
foreach (BaseObject item in this.Items) {
item.ObjectState = ObjectState.Unchanged;
}
DeletedRows.Clear();
}
Hi Goran,

Thanks. The using syntax works, but I still have problem converting the
definition
for the generic T. I

public abstract class BaseList<T of BaseObject> : BindingList<T>

- I want the generic key argument inherits properties defined in BaseObject.

Originaal VB.NET syntax is:

Public MustInherit Class BaseList(Of T As BaseObject) Inherits BindingList(Of
T)

Cheers,

Alan L.


Göran Andersson said:
- Visusal Studio error: 'T' does not contain a definition for 'ObjectState'
Click to expand...
C# is case sensetive while VB is not. Have you checked the exact name,
so it isn't for example "objectState"?
- my approach:
Click to expand...
[quoted text clipped - 5 lines]
Syntax error, '(' expected
Click to expand...
using (txScope) {
...
}
Click to expand...
Click to expand...
 
Google instant C#, this application will translate your VB code into C#. It
is very good.

--
Regards,
Alvin Bruney
------------------------------------------------------
Shameless author plug
Excel Services for .NET is coming...
OWC Black book on Amazon and
www.lulu.com/owc
Professional VSTO 2005 - Wrox/Wiley
 
alee said:
Public MustInherit Class BaseList(Of T As BaseObject) Inherits BindingList(Of
T)
Click to expand...

public abstract class BaseList<T> : BindingList<T>
where T : BaseObject


-- Barry
 
Hello Mehdi,

Thanks for your suggestions, and they work well.

Regards,

Alan L.
Hello,
Click to expand...
[quoted text clipped - 53 lines]
Hi,

The first equivalent:
Well, you are trying to use a class (T) that is supposed to have an
ObjectState property. However, this should be explicitly declared
using the "where" keyword in C#. You need to change the class
definition to something as follows:

public class MyClass<T> where T: BizObjBase

this tells the compiler that T is of type BizObjBase...

The second equivalent:
using (TransactionScope txScope = new TransactionScope())
{
//do whatever you need with txScope
}

HTH,
Mehdi
Click to expand...
 
Hello Barry,

Thanks for your suggestion, and it does solve the problem.

Regards,

Alan L.
 
Hi Goran

The BaseObject will be inherited by other classes. And I am defining an
extension to the
BindingList<T>.

I solved the problem by using the where keyworkd suggested by Barry and Mehdi.


Thanks for your feedback.

Regards,

Alan L.

Göran Andersson said:
If you have a base class for all objects that the class handles, then
you don't need to use generics at all in your class. Just use the base
class when you inherit the BindingList.

public abstract class BaseList : BindingList<BaseObject>

Now your BaseList is a BindingList that handles any object that inherits
from BaseObject.

In your method that loops the items, just reference them as BaseObject:

public void AcceptChanges() {
foreach (BaseObject item in this.Items) {
item.ObjectState = ObjectState.Unchanged;
}
DeletedRows.Clear();
}
Hi Goran,
Click to expand...
[quoted text clipped - 26 lines]
Click to expand...
 
Back
Top