Converting integer value to ASCII char

Question

I'm trying to use an integer value to its corresponding ASCII character:

char c = char(65); //65 equivalent to A character 
MessageBox::Show(System::Convert::ToString(c), "Conversion",
                    MessageBoxButtons::OK, MessageBoxIcon::Error);

This method just displays "65" in the message box rather than the character A. Is there any way of displaying the character instead of the number in C++/CLI? I've tried multiple other methods but they don't seem to work.

Answer 1

This is an issue where the C++ and .Net types don't match up the way you expect them to.

In .Net, there is a distinct type for characters: System::Char, or just Char if you have using namespace System;. (Note the capital "C", it's important.) This is a distinct type from System::UInt16 or System::Int16, even though it's the same size.

In C++, char and unsigned char are the smallest types. There is no distinction between a one-byte character vs. a one-byte integer.

When mapping C++ types onto .Net types, char maps to System::Byte, which is a numeric type. That's why you're getting a string containing the word "65" in your conversion.

If you want something that .Net recognizes as a character, not a number, then you need to cast to Char (with the capital "C" to make it System::Char). Then you can call .ToString() to get "A" instead of "65".

My test program:

int main(array<String^>^ args)
{
    char native = (char)65;
    Debug::WriteLine(native.ToString());

    Char c = (Char)65;
    Debug::WriteLine(c.ToString());

    return 0;
}

Result:

65
A