Global visibility with Managed types

[Steve Marsden]

Hi

As a C programmer just starting to look at Managed C++, I was shocked to
find that you cannot declare a managed type globally so that for example in
a partiuclar module you can declare some data globally so that all functions
in that module can see it to save passing it about as parameters.

How do you achieve the same thing with Managed C++ managed data.

Thanks

Steve

[Ashok K Kumar]

Declare a class with static data members.

--
------------------------------
Ashok K Kumar
------------------------------
"Steve Marsden" <st***@conquest .ltd.uk> wrote in message
news:ec******** ******@TK2MSFTN GP14.phx.gbl...

Hi

As a C programmer just starting to look at Managed C++, I was shocked to
find that you cannot declare a managed type globally so that for example in a partiuclar module you can declare some data globally so that all functions in that module can see it to save passing it about as parameters.

How do you achieve the same thing with Managed C++ managed data.

Thanks

Steve

[Steve Marsden]

Ashok

Thanks for the reply. I can see how this preserves the value of the data
members but how does this give visibilty of the class to other functions in
the module.

Thansk

Steve
"Ashok K Kumar" <As*********@di scussions.micro soft.com> wrote in message
news:eE******** ******@TK2MSFTN GP11.phx.gbl...

Declare a class with static data members.

--
------------------------------
Ashok K Kumar
------------------------------
"Steve Marsden" <st***@conquest .ltd.uk> wrote in message
news:ec******** ******@TK2MSFTN GP14.phx.gbl...

Hi

As a C programmer just starting to look at Managed C++, I was shocked to
find that you cannot declare a managed type globally so that for example

in

a partiuclar module you can declare some data globally so that all

functions

in that module can see it to save passing it about as parameters.

How do you achieve the same thing with Managed C++ managed data.

Thanks

Steve

[Tomas Restrepo \(MVP\)]

Steve,

Ashok

Thanks for the reply. I can see how this preserves the value of the data
members but how does this give visibilty of the class to other functions in the module.

The same way you'd give visibility of any type to a function in another
module.... a header file!

--
Tomas Restrepo
to****@mvps.org

[Ashok K Kumar]

If you have a int variable as global as follows in C

int iValue;

in C++ terms
//in the .h file
Class CGlobal // or any name
{
public:
static int iValue;
};

//in the .cpp file
int CGlobal::iValue = 100; // or initialize to some thing else in necessary.
Include the .h file whereever you need to access the global value.
--
------------------------------
Ashok K Kumar
------------------------------
"Steve Marsden" <st***@conquest .ltd.uk> wrote in message
news:%2******** ********@TK2MSF TNGP14.phx.gbl. ..

Ashok

Thanks for the reply. I can see how this preserves the value of the data
members but how does this give visibilty of the class to other functions in the module.

Thansk

Steve
"Ashok K Kumar" <As*********@di scussions.micro soft.com> wrote in message
news:eE******** ******@TK2MSFTN GP11.phx.gbl...

Declare a class with static data members.

--
------------------------------
Ashok K Kumar
------------------------------
"Steve Marsden" <st***@conquest .ltd.uk> wrote in message
news:ec******** ******@TK2MSFTN GP14.phx.gbl...

Hi

As a C programmer just starting to look at Managed C++, I was shocked to find that you cannot declare a managed type globally so that for

example in

a partiuclar module you can declare some data globally so that all

functions

in that module can see it to save passing it about as parameters.

How do you achieve the same thing with Managed C++ managed data.

Thanks

Steve

[Steve Marsden]

Ashok

Thanks again for reply abd your attempts to explain this but I still don't
understand nor can I get this to work with some test code. I must be missing
something as a lonstanding C programmer but newbie managed C++ programmer.

I understand you need to include the header file to see the definition of a
class. That's not what I want. I want to see the actual class throughout the
module. I understand the static int in the class will retain its value, its
how do I see the class I have declared. So in C

int gvar;

void test(void)
{
gvar=100;
}

void test2(void)
{
gvar=gvar+200;
}

This all works as gvar is global but in managed C++

#using <mscorlib.dll >

__gc class aclass
{
public:
static int gvar;
};

void test(void)
{
aclass *myclass=new aclass();

myclass->gvar=100; // This is fine
}

void test2(void)
{
myclass->gvar=myclass->gvar+200; // test2 doesnt know myclass beacuse
not global
}

and I can't declare myclass as global as its a managed type.

So how does test2 see myclass without having to pass it as a a parameter

Thanks

Steve
"Ashok K Kumar" <As*********@di scussions.micro soft.com> wrote in message
news:uh******** ******@TK2MSFTN GP12.phx.gbl...

If you have a int variable as global as follows in C

int iValue;

in C++ terms
//in the .h file
Class CGlobal // or any name
{
public:
static int iValue;
};

//in the .cpp file
int CGlobal::iValue = 100; // or initialize to some thing else in
necessary.
Include the .h file whereever you need to access the global value.
--
------------------------------
Ashok K Kumar
------------------------------
"Steve Marsden" <st***@conquest .ltd.uk> wrote in message
news:%2******** ********@TK2MSF TNGP14.phx.gbl. ..

Ashok

Thanks for the reply. I can see how this preserves the value of the data
members but how does this give visibilty of the class to other functions

in

the module.

Thansk

Steve
"Ashok K Kumar" <As*********@di scussions.micro soft.com> wrote in message
news:eE******** ******@TK2MSFTN GP11.phx.gbl...

> Declare a class with static data members.
>
> --
> ------------------------------
> Ashok K Kumar
> ------------------------------
> "Steve Marsden" <st***@conquest .ltd.uk> wrote in message
> news:ec******** ******@TK2MSFTN GP14.phx.gbl...
>> Hi
>>
>> As a C programmer just starting to look at Managed C++, I was shocked to >> find that you cannot declare a managed type globally so that for example > in
>> a partiuclar module you can declare some data globally so that all
> functions
>> in that module can see it to save passing it about as parameters.
>>
>> How do you achieve the same thing with Managed C++ managed data.
>>
>> Thanks
>>
>> Steve
>>
>>
>
>

[Ashok K Kumar]

I get what you mean. It is so obvious thing that we miss to mention it very
often. (and often assume that you guys would understands our lingo)

aclass *myclass=new aclass();

You dont have to create an object at all. You can access them using
"aclass::gv ar". "::" is called scope resolution operator.

so the code would be
void test(void)
{
aclass::gvar = 100;
}

void test2(void)
{
aclass::gvar += 200; // += means aclass::gvar = aclass::gvar + 200.
Another C++ stuff
}

I guess, you will have to learn a lot C++ concepts before you could jump
into managed C++. Pick up a good book on C++.

[Steve Marsden]

Thanks again Ashok

Now I understand. I am just reading through managed C++ and .NET devleopment
and after your last post have found the section on static member methods.

Steve

"Ashok K Kumar" <As*********@di scussions.micro soft.com> wrote in message
news:%2******** ********@TK2MSF TNGP15.phx.gbl. ..

I get what you mean. It is so obvious thing that we miss to mention it very
often. (and often assume that you guys would understands our lingo)

aclass *myclass=new aclass();

You dont have to create an object at all. You can access them using
"aclass::gv ar". "::" is called scope resolution operator.

so the code would be
void test(void)
{
aclass::gvar = 100;
}

void test2(void)
{
aclass::gvar += 200; // += means aclass::gvar = aclass::gvar + 200.
Another C++ stuff
}

I guess, you will have to learn a lot C++ concepts before you could jump
into managed C++. Pick up a good book on C++.