Managed C++/CLI

18-Aug-05 17:59

You can't just move header files in libraries around, you need to make sure you're able to see them ( that their folder is in your lookup path, or you've explicitly stated the path to the file ).

Christian Graus - Microsoft MVP - C++

Re: including pthread.h

Geilkonijn19-Aug-05 4:23

Geilkonijn

19-Aug-05 4:23

Thank you for the answer, I'm a total beginner but would like to figure this out.

I have set the path with :

C:\program files\borland\CBuilder6\include\stlport;

I added that line to path under Enviroment Variables in computer properties.

The path is clearly added (when I type path in command box its there)

But I still get the error that pthread.h cannot be opened Frown | :(

Edit :
Nevermind, I found it Smile | :)

Re: including pthread.h

S. Senthil Kumar19-Aug-05 8:13

Re: Excel Program in c++?

19-Aug-05 8:13

You need to do add it to the Include path in Visual Studio.

Regards
Senthil
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Excel Program in c++?

Anonymous17-Aug-05 16:35

Anonymous

17-Aug-05 16:35

I was doing my homework, which consists of defining a bunch of terms...

Is there some way to write a program that takes values from a cell and searches on google "define x" and then prints the value in another cell?

or it doesn't have to be a cell but maybe just a text document?

could someone help me out with where to start? how do you go about calling a webpage within a program? will it work with c++?

thanks for all your help.

Christian Graus17-Aug-05 17:08

Re: Excel Program in c++?

17-Aug-05 17:08

Anonymous wrote:
could someone help me out with where to start?

The starting point would be the COM interface exposed by Excel. I'm sure it can do what you want. Launching a browser with a google URL is also easy, ShellExecute will do that. The hard part would be to take a list of URLs and from that get a meaningful value to pass back into Excel.

Christian Graus - Microsoft MVP - C++

Tim Zorn21-Aug-05 5:52

Tim Zorn

21-Aug-05 5:52

i could help u out put if u have an Instant messenger SN that would be easy cuz than u or i dont have to wait for replys
my AIM SN = KilroyWasHere00

ReferenceEquals not behaving logically

ChuckStar17-Aug-05 11:35

17-Aug-05 11:35

public ref struct PointRef
{
PointRef()
{
runTime = 0;
ampl = 0;
}

PointRef(unsigned long runTime_, unsigned long ampl_)
{
runTime = runTime_;
ampl = ampl_;
}

PointRef(PointRef const % src)
{
runTime = src.runTime;
ampl = src.ampl;
}

unsigned long runTime;
unsigned long ampl;
};

void main()
{
List<PointRef^> errList(numPts);
List<PointRef^> errListCopy(numPts);

for (int idx = 0; idx < numPts; ++idx)
errList.Add(gcnew PointRef(idx, idx));

errListCopy.AddRange(%errList);
if (Object::ReferenceEquals(errList[0], errListCopy[0]))
{
int i = 0; // Never gets here
}

int b = 1; // Set breakpoint here
}

When I get to the breakpoint b=1, I look in the debugger watch window for errList[0] and errListCopy[0]. The addresses for the two are different. When I change the ampl value for either object, the other object changes as well. This acts correctly because the AddRange is copying the references so both lists should be pointing to same objects. My question is why does the ReferenceEquals return false because they refer to the same instance and why do the references have different addresses?

Thanks, Charlie

Christian Graus17-Aug-05 12:01

17-Aug-05 12:01

ChuckStar wrote:
List<pointref^> errList(numPts);
List<pointref^> errListCopy(numPts);

for (int idx = 0; idx < numPts; ++idx)
errList.Add(gcnew PointRef(idx, idx));

errListCopy.AddRange(%errList);

You have two lists here. They contain the same data because you copied one to the other. At least, I think that's what the last line does, and the % is a typo. Either way, there is nothing here to suggest that they are both the same list, just two lists of the same items.

Christian Graus - Microsoft MVP - C++

ChuckStar18-Aug-05 4:03

18-Aug-05 4:03

Thanks for your response Christian. You are correct about the lists containing the same data. To be exact, they contain the same instances of the data. That is what the AddRange function says it does. Copy the contents of the list. The contents are references to objects. As I stated, if I change the ampl member of errList[0], errListCopy[0] gets the change too. This shows that they refer to the same instance as the documentation states. The % is not a typo. This is .NET Beta2 code and the errList is on the stack and the AddRange function takes a reference (^).

If you have any other suggestions, I would like to hear them. Thanks.

Charlie

Christian Graus18-Aug-05 14:57

18-Aug-05 14:57

You've got two lists that contain the same data. It seems to me that referenceequals would return true if you had two copies of the same list class instance, rather than two instances of the list class with the same objects in them.

But I'm guessing.

Christian Graus - Microsoft MVP - C++

Saksida Bojan17-Aug-05 20:26

Saksida Bojan

17-Aug-05 20:26

try this:
errList[0]->Equals(errListCopy[0]);

ps: i can't compile, but when i use string compare i found that this method work.

ChuckStar18-Aug-05 4:26

18-Aug-05 4:26

I tried this also with the same result. The problem with this equals is that Object.Equals is a comparison of the references if the object is a reference, but derived classes can change this to a value equality (see the documentation for more details). It is better to use the ReferenceEquals to ensure you are really determining if the references are refering to the same instance of the object. This is very confusing.

The only things I didn't have in my code to make it compile is:
using namespace System::Collections::Generic;
at the top of the file and
int numPts = 100000;
at the top of main.

Actually I just tried this on another machine and it worked. I am using the .NET Beta2 and I may have an older install on the other machine. I will try it again on that machine and let you know.

Thanks, Charlie

ChuckStar18-Aug-05 7:38

18-Aug-05 7:38

I figured out one problem. That is why the ReferenceEquals is returning false. Somehow, my compile switch got changed to /02 (optimization = Max speed). If I change it to /Od (Disabled), the ReferenceEquals returns true. This seems like a defect in the compiler. I will submit this to Microsoft.

I still don't understand the debugger watch window showing different addresses for the errList[0] and errListCopy[0] references though.

Thanks all for the comments.

Charlie

Nish Nishant18-Aug-05 23:55

Nish Nishant

18-Aug-05 23:55

Hello Charlie

I tried both Debug and Release builds. It works as expected for me.

Here's my Release build compiler command line :-

/O2 /D "WIN32" /D "NDEBUG" /D "_MBCS" /FD /EHa /MD /Yu"stdafx.h" /Fp"Release\Test_Del.pch" /Fo"Release\\" /Fd"Release\vc80.pdb" /W3 /nologo /c /Zi /clr /TP /errorReport:prompt /FU

void main()
{
	int numPts = 10;
	List< PointRef^ > errList(numPts);
	List< PointRef^ > errListCopy(numPts);

	for (int idx = 0; idx < numPts; ++idx)
		errList.Add(gcnew PointRef(idx, idx));

	errListCopy.AddRange(%errList);
	if (Object::ReferenceEquals(errList[0], errListCopy[0]))
	{
		int i = 0; 
		Console::WriteLine("here"); //gets here alright
	}

	int b = 1;  // Set breakpoint here
}

I am using VS.NET Beta 2

Regards,
Nish

S. Senthil Kumar19-Aug-05 4:21

19-Aug-05 4:21

How is that possible? PointRef is a ref struct, errList[0] and errListCopy[0] should get boxed into two different objects, right?

Regards
Senthil
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My Blog | My Articles | WinMacro

Nish Nishant19-Aug-05 15:03

Nish Nishant

19-Aug-05 15:03

S. Senthil Kumar wrote:
How is that possible? PointRef is a ref struct, errList[0] and errListCopy[0] should get boxed into two different objects, right?

Hello Senthil

In C++, a ref struct and a ref class are both reference types. While a value struct and a value class are value types. So, PointRef in the above example is *not* a value type.

S. Senthil Kumar19-Aug-05 21:14

19-Aug-05 21:14

I keep forgetting that there are ref and value prefixes to structs. Thanks for clearing that up.

Regards
Senthil
_____________________________
My Blog | My Articles | WinMacro

S. Senthil Kumar19-Aug-05 7:55

19-Aug-05 7:55

Oh crap, PointRef ^x = gcnew PointRef itself seems to create a boxed object. Yet another thing I have to remember when I switch between C++/CLI and C#.

Regards
Senthil
_____________________________
My Blog | My Articles | WinMacro

How to achieve 'True' transparency with pictureBox??

Nish Nishant19-Aug-05 15:04

Nish Nishant

19-Aug-05 15:04

S. Senthil Kumar wrote:
Oh crap, PointRef ^x = gcnew PointRef itself seems to create a boxed object.

No - PointRef is a reference type - there is no boxing involved here.

richiemac17-Aug-05 4:15

richiemac

17-Aug-05 4:15

Hi all,

I've got a form with a number of picture boxes. I now want to add a small picturebox on top of these main boxes and be able to see the main box through the small box. If I set the background colour to transparent it, as you probably know, will show the main forms background. Is there a way that I can set the parent of the small box to be the main box?

If not how do I go about creating a picturebox that does have true transparency. I presume I can write my own pictureBox class but don't know how and what I would need to override. Does anyone have any idea because I'm dying here guys!! Smile | :)

Re: How to achieve 'True' transparency with pictureBox??

Christian Graus17-Aug-05 12:02

Re: How to achieve 'True' transparency with pictureBox??

17-Aug-05 12:02

Forget the stupid picture box and draw your own image onto the screen.

Christian Graus - Microsoft MVP - C++

richiemac18-Aug-05 3:36

richiemac

18-Aug-05 3:36

So how do I draw a transparent image?

Re: How to achieve 'True' transparency with pictureBox??

Christian Graus18-Aug-05 14:55