root/trunk/docsrc/windows.dd

Ddoc

$(D_S D for Win32,

    $(P This describes the D implementation for 32 bit Windows systems.
    Naturally,
    Windows specific D features are not portable to other platforms.
    )

    $(P Instead of the:)

$(CCODE
#include <windows.h>
)
    $(P of C, in D there is:)

--------------------
import std.c.windows.windows;
--------------------


<h2>Calling Conventions</h2>

    $(P In C, the Windows API calling conventions are $(CODE __stdcall).
    In D, it is simply:
    )

--------------------
extern (Windows)
{
    /* ... function declarations ... */
}
--------------------


    $(P The Windows linkage attribute sets both the calling convention
    and the name mangling scheme to be compatible with Windows.
    )

    $(P For functions that in C would be $(CODE __declspec(dllimport)) or
    $(CODE __declspec(dllexport)), use the $(CODE export) attribute:
    )

--------------------
export void func(int foo);
--------------------

    $(P If no function body is given, it's imported. If a function body
    is given, it's exported.
    )

<h2>Windows Executables</h2>

    $(P Windows GUI applications can be written with D.
    A sample such can be found in $(TT $(DMDDIR)\samples\d\winsamp.d)
    )

    $(P These are required:)

    $(OL 

    $(LI Instead of a $(CODE main) function serving as the entry point,
    a $(CODE WinMain) function is needed.
    )

    $(LI $(CODE WinMain) must follow this form:
--------------------
import core.runtime;
import std.c.windows.windows;

extern (Windows)
int $(B WinMain)(HINSTANCE hInstance,
    HINSTANCE hPrevInstance,
    LPSTR lpCmdLine,
    int nCmdShow)
{
    int result;

    void exceptionHandler(Exception e)
    {
    throw e;
    }

    try
    {   
    Runtime.initialize(&exceptionHandler);

    result = $(B myWinMain)(hInstance, hPrevInstance, lpCmdLine, nCmdShow);

    Runtime.terminate(&exceptionHandler);
    }

    catch (Object o)        // catch any uncaught exceptions
    {
    MessageBoxA(null, cast(char *)o.toString(), "Error",
            MB_OK | MB_ICONEXCLAMATION);
    result = 0;     // failed
    }

    return result;
}

int $(B myWinMain)(HINSTANCE hInstance,
    HINSTANCE hPrevInstance,
    LPSTR lpCmdLine,
    int nCmdShow)
{
    /* ... insert user code here ... */
}
--------------------

    The $(TT myWinMain()) function is where the user code goes, the
    rest of $(TT WinMain) is boilerplate to initialize and shut down
    the D runtime system.
    )

    $(LI A $(CODE .def)
    ($(LINK2 http://www.digitalmars.com/ctg/ctgDefFiles.html, Module Definition File))
    with at least the following
    two lines in it:

$(MODDEFFILE
EXETYPE NT
SUBSYSTEM WINDOWS
)

    Without those, Win32 will open a text console window whenever
    the application is run.
    )

    $(LI The presence of $(TT WinMain()) is recognized by the compiler
        causing it to emit a reference to
        $(LINK2 http://www.digitalmars.com/ctg/acrtused.html, __acrtused_dll)
        and the phobos.lib runtime library.
    )

    )
)

Macros:
    TITLE=Windows
    WIKI=Windows