Managed C++/CLI

Can we reduce this function (x<-3 || x >3) further

8-Jul-08 0:22

Hello!
You could use Invoke or BeginInvoke/EndInvoke to let
the main thread execute your delegate.
With Invoke, the worker thread waits until the handlers
have completed. There are examples in the msdn.

Alex

pallaka7-Jul-08 20:18

pallaka

7-Jul-08 20:18

Can we reduce this function further in one simple statment as the compared number from -3 to +3 is same

Re: Can we reduce this function (x<-3 || x >3) further

LionAM8-Jul-08 0:35

Re: Can we reduce this function (x<-3 || x >3) further

8-Jul-08 0:35

I don't think so.
(you could use abs(x) > 3, but I don't think it would be faster)

pallaka8-Jul-08 1:32

pallaka

8-Jul-08 1:32

Thanks for the reply but it is taking more CPU time than the given one.

Re: Can we reduce this function (x<-3 || x >3) further

killabyte8-Jul-08 2:07

killabyte

8-Jul-08 2:07

if u are worried about CPU time taken for such a simple operation then i would check the ASM output that is generated from the code, i think u will find that a number of C code options will boil down to the same ASM in the end.

What is the proper way to add a form to an existing class?

BuckBrown7-Jul-08 5:55

BuckBrown

7-Jul-08 5:55

Hi. I'm using Visual Studio C++/CLI. I have a well developed class that now has a need to have a user interface for it. Normally I will determine if I need a form associated with a class when I create the class, so the class is created as a System::Windows::Forms::Form. But now I have a class that I did not think would need a form associated with it so it was defined as a simple C++ ref class. What is the proper way to add a form to the class? Should I create a new UI Forms based class and cut and paste everything in my existing class into it? Or is there a simple way to instantiate a new form as a method of the existing class?

Thanks,
Buck

Re: What is the proper way to add a form to an existing class?

led mike7-Jul-08 6:16

led mike

7-Jul-08 6:16

BuckBrown wrote:
Normally I will determine if I need a form associated with a class when I create the class, so the class is created as a System::Windows::Forms::Form. But now I have a class that I did not think would need a form associated with it so it was defined as a simple C++ ref class. What is the proper way to add a form to the class? Should I create a new UI Forms based class and cut and paste everything in my existing class into it? Or is there a simple way to instantiate a new form as a method of the existing class?

Buck, what's up dude? Ever heard of Object Oriented Design Principles, Best Practices, Separation of Concerns, Design Patterns, Model-View-Controller?

Any of this ringing any bells with you? You don't tightly couple a "class" with the presentation layer of your design, it's not considered Best Practice and there are Patterns like MVC that represent solutions for this.

led mike

Re: What is the proper way to add a form to an existing class?

BuckBrown7-Jul-08 7:45

BuckBrown

7-Jul-08 7:45

Hi Mike,

Just so you know, I first learned programming using assembly on a state of the art Intel 8085 and our operating system was CP/M (that's what it was called before Microsoft bought it and renamed it MS-DOS). Over the years I have been forced to learn various programming languages on Data General, VAX, UNIX, and MS-DOS boxes, but all of the OO stuff was invented long after I got out of college. So the fact that I'm an over 50 microelectronics engineer with a EE degree and not a new Computer Science graduate, I can state with confidence that with the exception of Object Oriented Design Principles I've never heard of any of those terms before (nor whatever MVC means). You even mention a "presentation layer". I have never heard anyone use that term before. IO, User Interface, GUI sure, but "presentation layer"? I don't understand what you mean by "you don't tightly couple a class with the presentation layer". Visual Studio's forms designer seems to make things very tightly coupled. Anyways, if you could dumb down your responses for me that would be cool.

Thanks,
Old Buck

And my applications always work and do what they were designed to do.

Re: What is the proper way to add a form to an existing class?

led mike7-Jul-08 9:17

led mike

7-Jul-08 9:17

Hey Buck, sorry about that, I had no idea.

Most of those terms can be googled and wikipedia is a good introduction to most of them as well.

http://en.wikipedia.org/wiki/Separation_of_concerns[^]
http://www.google.com/search?hl=en&q=wikipedia+design+patterns&btnG=Search[^]
http://en.wikipedia.org/wiki/Model-view-controller[^]
http://en.wikipedia.org/wiki/Presentation_layer[^]
Prefer Loose Coupling[^]

If you are doing .NET development you should check out the Microsoft Patterns and Practices Center[^]

In OOD the simplest example of how to avoid tight coupling is if you have two classes that represent different things so there is no reason for them to "know" of each other, they have no relationship or association.

class A class B

Now you find a use model or activity for which the solution can use both of them. Bad Practice would be to modify either one or both to use them in combination resulting in a relationship or association. Best Practice would be to create a 3rd class that has a relationship to both the others and implements the solution combining the first two classes. This maintains the isolation between the first two classes.

class A           class B<br />
   \                /<br />
    \              /<br />
     \            /<br />
        class C<br />

led mike

Re: What is the proper way to add a form to an existing class?

killabyte7-Jul-08 23:37

killabyte

7-Jul-08 23:37

Easy way would just be to make a new form class and make the class a member of the new form class. ugly? yes. best practise? no. will it do the trick? probably Smile | :)

How can i create multiple instances of form

Xaria6-Jul-08 18:28

Xaria

6-Jul-08 18:28

How To create an array of form?

Re: How can i create multiple instances of form

Giorgi Dalakishvili6-Jul-08 21:44

Giorgi Dalakishvili

6-Jul-08 21:44

You create form array in the same way as you would create array of any other type.

Giorgi Dalakishvili

#region signature
my articles
#endregion

Bounded mouse position when moving child form

LionAM5-Jul-08 12:16

Re: Bounded mouse position when moving child form

5-Jul-08 12:16

Still another question:

I want to create a .NET equivalent to the MFC CDialogBar.
When I move a form which is a child of a panel,
the mouse position is bounded by the panel,
even if I set

Parent = nullptr;
TopLevel = true;

on first Move-Event and even if the panel is not
visible any more. Is there a workaround?

Alex

LionAM6-Jul-08 6:26

Re: Bounded mouse position when moving child form

6-Jul-08 6:26

Hello!
For the mouse, I found a solution:
The allowed mouse position is bounded by the Cursor->Clip property.
But still the window can not be moved completely out of the panel,
it stops at the border.

Alex

LionAM7-Jul-08 9:18

7-Jul-08 9:18

Ok, nearly solved.
When I override the WndProc-Method and process the WM_SYSCOMMAND(SC_MOVE) Message,
I can reset the Parent-property and the window is not bounded any more.

Alex

GetType for class

LionAM5-Jul-08 6:20

5-Jul-08 6:20

Hello!

I want to compare the type of an object to a class.
What is the correct syntax to use? In my case, I
want to know if a control is an instance of MdiClient.
GetType works on the pointer, but not on the class.
typeid(MdiClient) gives me error C3767.

Alex

Mark Salsbery5-Jul-08 9:29

5-Jul-08 9:29

if (some_ref_handle->GetType() == MdiClient::typeid)
{
   //some_ref_handle references a MdiClient object!
}

LionAM5-Jul-08 9:47

5-Jul-08 9:47

Thank you!
At first I got an error because MdiClient is a private(?) member
of the class (which is not shown in the IntelliSense list).
But with
Windows::Forms::MdiClient::typeid
it works.

Alex

Mark Salsbery5-Jul-08 9:53

5-Jul-08 9:53

Cool

LionAM wrote:
MdiClient is a private(?) member
of the class

MdiClient IS the class.

LionAM wrote:
But with
Windows::Forms::MdiClient::typeid
it works.

Oops - I guess I assumed "using namespace Windows::Forms;"

typeid needs to know the type at compile time. You could also use something like

if (some_ref_handle->GetType() == Type::GetType("Windows::Forms::MdiClient"))

for a runtime check.

Cheers,
Mark

LionAM5-Jul-08 12:00

5-Jul-08 12:00

Hello!

::MdiClient::typeid works, but MdiClient::typeid
gives

error C3223: 'System::Windows::Forms::Form::MdiClient' : you cannot apply 'typeid' to a property

Alex

Mark Salsbery5-Jul-08 12:43

5-Jul-08 12:43

MdiClient is in the System::Windows::Forms namespace, not the
System::Windows::Forms::Form namespace (which doesn't exist -
System::Windows::Forms::Form is a class).

Either of these should work:

using namespace System::Windows::Forms;
...
   if (objectref->GetType() == MdiClient::typeid)

if (objectref->GetType() == System::Windows::Forms::MdiClient::typeid)

Mark

UDP messages

dSolariuM5-Jul-08 3:26

dSolariuM

5-Jul-08 3:26

Hi all,
I have a server application that sends a udp message to clients,
But it receives the message as well,
And I don't want this....
I want only other clients Receive the message.
Please help me,
Thank you.

Every new thing you learn,Gives you a new personality.

Re: UDP messages

Mark Salsbery5-Jul-08 9:31