Visual Basic

1-Sep-11 5:27

Hello !
have a form on vb.net bounded with a bindingsource on entity framework.
when the form is closed , should i dispose entity or bindingsource?

Dave Kreskowiak1-Sep-11 7:45

1-Sep-11 7:45

Rule of thumb: If the object has a Dispose method, call it before the object goes out of scope.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak

dcode251-Sep-11 13:17

1-Sep-11 13:17

My request is for a specific situation :
Entity framework created directly from existing database (sql server), A form with a bindingsource.
When the form is open the code is :

Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
Dim f As unEntities
f = New unEntities
FaBindingSource.DataSource = f.fas
End Sub

What can i put on :

Private Sub Form1_FormClosed(sender As System.Object, e As System.Windows.Forms.FormClosedEventArgs) Handles MyBase.FormClosed

f.dispose ????????????????
FaBindingsource.dispose ??????
FaBindingsource.clear() ??????????
or ????????
End Sub

Thank you

Dave Kreskowiak1-Sep-11 16:48

1-Sep-11 16:48

I highly suggest you pick up and work through a book on C#.

Since f is declared in the Load event handler method, it cannot be seen outside of that method. Trying to do a f.Dipose() anywhere else will cause the compiler to throw an error at you.

Next, no, you don't have to Dispose a BindingSource, even though it has a Dispose method.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak

dcode252-Sep-11 7:30

2-Sep-11 7:30

ok maybe my question is wrong . The real situation is :
i have a form with select buttons that i use to move through records.I select for example the third record and after that i close the form.If a reopen the form , the third record is selected.i don't want this situation.When the form is loaded , the first record should be selected.I know that i can put something like moveToFirst method , but i dont want this.I try to put bindingsource.dispose on closing form sub , and this has not resolved the problem.if i put bindingsource.clear() the problem is resolved.
So i just want to understand the situation , after the form is closed the bindingsource keeps the records ??

Anyway , thank you !

Dave Kreskowiak2-Sep-11 11:18

2-Sep-11 11:18

Disposing the thing doesn't have anything to do with this. It sounds as though your problem is that once you dismiss the form, you're reusing it instead of destroying it and creating a new instance of the form. But, you haven't said much about your application of what this form is for so it's pretty difficult to tell you where you're going wrong.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak

dcode252-Sep-11 11:55

2-Sep-11 11:55

i have a menu on my application.And the code in menu item to open this form is :
form1.showdialog

After the form is closed using x button

Dave Kreskowiak2-Sep-11 15:45

2-Sep-11 15:45

OK, so after the .ShowDialog call, do what you need to do with the data on the form and .Dispose it. Then in the menu click code you can create a new instance of the form like it never existed before in the first place.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak

dcode253-Sep-11 7:09

3-Sep-11 7:09

ok.
but should i call form1.dispose(true) or form1.dispose(false) ?

Dave Kreskowiak3-Sep-11 8:28

3-Sep-11 8:28

Neither.

You've never shown a dialog form before, have you?

A guide to posting questions on CodeProject[^]

Dave Kreskowiak

Luc Pattyn1-Sep-11 7:57

Luc Pattyn

1-Sep-11 7:57

As Dave said.
unless you didn't create, or cause the creation, of the object (as in Brushes.Black).

Smile | :)

Luc Pattyn [My Articles] Nil Volentibus Arduum

Setting a COM reference to a VB6 Project in C#

DaveAuld1-Sep-11 9:13

DaveAuld

1-Sep-11 9:13

There is a blog discussing Dispose on MSDN; when-to-call-dispose[^]

There is also a link within the blog on in depth guidelines on use and implementation of Dispose.

As you will see at the bottom of the Blog there is a summary guidance section details the MUST category and the Maybe's.......

Dave
Find Me On: Web|Facebook|Twitter|LinkedIn

Folding Stats: Team CodeProject

chiselca31-Aug-11 9:05

chiselca

31-Aug-11 9:05

I have a VB6 ActiveX EXE that I wrote some time ago and a VB6 application that references it. I am writing a C# version of that VB6 application.

In VB6 you can run the ActiveX EXE project in the IDE and set a reference to that ActiveX EXE VBP file in the other application's References. This lets you run both the application and the ActiveX EXE in their respective IDE's and step through the code in the application as well as the code in the ActiveX project.

I can find no way to set a reference to the VBP file in C#. I set the reference to the EXE file and my C# program works fine, but I miss being able to step through the ActiveX EXE code when debugging.

Is there some way to do this in C#?

I am using VS2005 for this project but I also have VS2010 installed.

Thanks in advance.
chiselca

Dave Kreskowiak1-Sep-11 3:36

1-Sep-11 3:36

You can't set a reference to a .VBP file, which would be the project file in VB6.

Debugging VB6 code is not supported in the .NET versions of Visual Studio.

[EDIT]
Let me rephrase that. You cannot modify VB6 code from VS2005 or 2010. You can step through it and still see it, so long as you're running the Debug version of your VB6 code and the source file can be found.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak

chiselca2-Sep-11 9:03

chiselca

2-Sep-11 9:03

Dave,

I am not sure I understand what you mean. Are you suggesting that if I set a breakpoint in my C# project on a line of code that calls into my VB6 EXE, that I can step through the VB6 project's source code in the Visual Studio IDE if I compile with symbolic Debug info?

I have never done this so I am not sure how to set it up.

Any help would be appreciated.

chiselca

Dave Kreskowiak2-Sep-11 11:19

2-Sep-11 11:19

There's nothing to setup. You compile your VB6 .DLL as Debug instead of Release. Then, in your C# project, you add a reference to the Debug version of the resulting .DLL. Done.

When you set a breakpoint in your C# app, you can step right into the VB6 code like it was native.

A guide to posting questions on CodeProject[^]

Dave Kreskowiak