Class and interface communication problem..

[Krillere]

Hello again :-)
Here I am with another stupid question.

I'm trying to make a class for a Log system. And I only just tried something with classes, and my first succesfull attempt was the following:

static void Click( int x, int y ) {
 
SetCursorPos( x, y );
 
mouse_event( MOUSEEVENTF_LEFTDOWN, 0,0,0,0 );
mouse_event( MOUSEEVENTF_LEFTUP, 0,0,0,0);
 
}

which could be called with:

Click( 100,100 );

That code worked, so I wanted to move on. So I wanted to do the following:

static void Log( String^ Message ) {
 
this->listBox1->Items->Add( Message );
 
}

But surprisingly that didn't work. ( Actually, after "this->" nothing appeared or anything..

When I compile that, I get the following errors:

(49) : error C2671: 'Klassetest::Form1::Log' : static member functions do not have 'this' pointers
(49) : error C2227: left of '->listBox1' must point to class/struct/union/generic type
(49) : error C2227: left of '->Items' must point to class/struct/union/generic type
(49) : error C2227: left of '->Add' must point to class/struct/union/generic type

So, how do I make that work in Visual C++ ? :-)

[WargRider]

Hello again :-)
Here I am with another stupid question.

I'm trying to make a class for a Log system. And I only just tried something with classes, and my first succesfull attempt was the following:

static void Click( int x, int y ) {
 
SetCursorPos( x, y );
 
mouse_event( MOUSEEVENTF_LEFTDOWN, 0,0,0,0 );
mouse_event( MOUSEEVENTF_LEFTUP, 0,0,0,0);
 
}

which could be called with:

Click( 100,100 );

That code worked, so I wanted to move on. So I wanted to do the following:

static void Log( String^ Message ) {
 
this->listBox1->Items->Add( Message );
 
}

But surprisingly that didn't work. ( Actually, after "this->" nothing appeared or anything..

When I compile that, I get the following errors:


So, how do I make that work in Visual C++ ? :-)

Because you either dont have any struct or union in the first place or you did not declare a variable of that struct or union type named "this". The "." and "->" are only used to access the inner variables of a struct or union. Especially the "->".

[Cypher]

Arghhh. Why are you using Managed C++?

Seriously. If you want to write managed code then use C#, if you want to write native code then use C++ (normal - i.e. ISO - C++, not 'Visual C++' or 'Managed C++').

Managed C++ is only good for some mixed-mode stuff and transitional stuff, it's such a bastardized language.

[Krillere]

Arghhh. Why are you using Managed C++?

Seriously. If you want to write managed code then use C#, if you want to write native code then use C++ (normal - i.e. ISO - C++, not 'Visual C++' or 'Managed C++').

Managed C++ is only good for some mixed-mode stuff and transitional stuff, it's such a bastardized language.

TBH, I did consider switching over to C#, but does it have the same functions as Managed C++ ? And can thoose functions just be imported? For instance, how do I #include <windows.h> ? Or will I have to DLLImport all the functions when I need them?
And thanks for the polite answer :-)

[Cypher]

TBH, I did consider switching over to C#, but does it have the same functions as Managed C++ ? And can thoose functions just be imported? For instance, how do I #include <windows.h> ? Or will I have to DLLImport all the functions when I need them?
And thanks for the polite answer :-)

You shouldn't need to use P/Invoke most of the time, as the .NET framework provides wrappers for the most common API uses.

What do you mean "does it have the same functions as managed c++"? I think you're confused about how .NET works...

[Krillere]

You shouldn't need to use P/Invoke most of the time, as the .NET framework provides wrappers for the most common API uses.

What do you mean "does it have the same functions as managed c++"? I think you're confused about how .NET works...

Sorry, I didn't think when I wrote it.
I just tested my C# Skills. And I figured out how to get a Window Handle:

[ System.Runtime.InteropServices.DLLImport( "user32.dll" ) ] 
static extern IntPtr FindWindow( string lpClassName, string lpWindowName );
 
IntPtr hWnd = FindWindow( null, "Some Window" );

But I couldn't check if the window existed like I could in ( Managed ) C++.

if( hWnd ) {

}
else {

}

it just errored.. How would I fix that? :-)

[Cypher]

Like this:

if (hWnd != 0)
{
}
else
{
}

C# doesn't have implicit void* to bool or int to bool conversions.

[Krillere]

Ok. That makes sense. Thanks! :-)

[Cypher]

Ok. That makes sense. Thanks! :-)

Yar. C# is stricter than C++ when it comes to type safety.

[Pragma]

As well as not using managed C++, you need to take out the static keyword of your function declaration, static member functions cannot access non-static class variables.