Array of structures in C++ .NET

  • Thread starter Thread starter ned
  • Start date Start date
N

ned

I have been having a lot of problems with an array of structures
embedded in another structure in C++ .NET and have boiled it down to
this very simple example:

Try the following steps, it will only take 5 minutes:

1) Create a new C++ .NET Windows Form project.

2) Create a new .h file and put in it:

typedef struct _mini
{
int iVal;
} miniStruct;

typedef struct _test
{
miniStruct mini[10];
} testStruct;


3) In the form1.h file, include the .h file you just created.

4) In the form1.h file Form_Load procedure:

testStruct test;
test.mini[0].iVal = 11;
test.mini[1].iVal = 22;


Please tell me why test.mini[1].iVal does not get set to 22. It is
always 0.

Does this have anything to do with the structures being an unmanaged
(native) C++? I am just learning about managed code and .NET, coming
from a Visual C++ world. I am trying currently to make the structs
above managed structs but having a lot of trouble trying to figure out
how to do an embedded array of structures in another structure using
the managed extensions.

Any help you can give would be greatly appreciated.

thank you.
 
I followed your directions, and added the line

MessageBox::Show(test.mini[1].iVal.ToString());

after the assignments, but it shows 22. What are you doing to get 0?

MessageBox::Show
 
James Park said:
I followed your directions, and added the line

MessageBox::Show(test.mini[1].iVal.ToString());

after the assignments, but it shows 22. What are you doing to get 0?

MessageBox::Show
Click to expand...


Yes you are right. The message box does show 22.

Where it showed 0 was in the debugger. If you debug through the code,
and put your cursor over test.mini[1].iVal, it shows 0. When you
Quickwatch 'test', it shows that test.mini[1].iVal is 0. Why?

Thanks for your reply,

ned
 
ned said:
James Park said:
I followed your directions, and added the line

MessageBox::Show(test.mini[1].iVal.ToString());

after the assignments, but it shows 22. What are you doing to get 0?
Click to expand...


Yes you are right. The message box does show 22.

Where it showed 0 was in the debugger. If you debug through the code,
and put your cursor over test.mini[1].iVal, it shows 0. When you
Quickwatch 'test', it shows that test.mini[1].iVal is 0. Why?

Thanks for your reply,

ned
Click to expand...

It looks like a bug:
http://www.dotnet247.com/247reference/msgs/44/222866.aspx

And that Ken Bayer guy speaks the truth as VS 2005 Beta 2 does not suffer
the same problem. :)
 
Back
Top