noob String::Format question

[Donald]

I am trying print the length of a managed array, but I cannot figure out how
to correctly cast the result so String::Format will use it. I wrote a simple
test to duplicate the problem (below) -- can anybody explain to me why the
following generates an error?

int ai __gc[] = new int __gc[100];
Console::WriteLine(ai->Length);
Console::WriteLine(String::Format(S"Length of ai is {0}",
__box(ai->Length)));
The first Writeline returns the correct answer but the last line generates
an error of "Object reference not set to an instance of an object".

Thanks in advance,
don.

 

[Doug Harrison [MVP]]

I am trying print the length of a managed array, but I cannot figure out how
to correctly cast the result so String::Format will use it. I wrote a simple
test to duplicate the problem (below) -- can anybody explain to me why the
following generates an error?

int ai __gc[] = new int __gc[100];
Console::WriteLine(ai->Length);
Console::WriteLine(String::Format(S"Length of ai is {0}",
__box(ai->Length)));
The first Writeline returns the correct answer but the last line generates
an error of "Object reference not set to an instance of an object".

ISTR there was a bug with the Length property in VC.NET 2002, which was
fixed in VC.NET 2003. Try using ai->get_Length() instead.

 

[Donald]

Thanks! I ended up doing

int i = ai->Length;

then using i in the WriteLine. Good to know that it is a bug... maybe I
should upgrade

I am trying print the length of a managed array, but I cannot figure out how
to correctly cast the result so String::Format will use it. I wrote a simple
test to duplicate the problem (below) -- can anybody explain to me why the
following generates an error?

int ai __gc[] = new int __gc[100];
Console::WriteLine(ai->Length);
Console::WriteLine(String::Format(S"Length of ai is {0}",
__box(ai->Length)));
The first Writeline returns the correct answer but the last line generates
an error of "Object reference not set to an instance of an object".

ISTR there was a bug with the Length property in VC.NET 2002, which was
fixed in VC.NET 2003. Try using ai->get_Length() instead.