cgo - How to convert go string to LPCWSTR

Question

I would like to use some of windows api, but I have no idea how to start. Is there any tutorial for it?

Anyway I have a simple code. Can you please help me to get this correct?

package mypackage
/*
#cgo LDFLAGS: -luser32
#include <windows.h>
*/
import "C"
import "unsafe"

func MessageBox(m string) {
      cm := C.CString(s)
      defer C.free(unsafe.Pointer(cm))
      C.MessageBoxA(C.HWND(nil), (*C.CHAR)(cm), C.LPCSTR(nil), 0) // It display a message.
}

Edit: I can deal with char* but still do not know what with wchar_t*.

import "syscall"

func MessageBoxU(m string) {
        C.MessageBoxW(C.HWND(nil), (*C.WCHAR)(unsafe.Pointer(syscall.StringToUTF16Ptr(m))), C.LPCWSTR(nil), 0)
}

Please let me know if this is not go idiom.

Answer 1

The following are two projects which wrap the Windows API to Go:

• github.com/antonlahti/go-winapi
• github.com/AllenDang/w32

A usage example:

    func setWidgetText(hwnd HWND, text string) error {
        if TRUE != go-winapi.SendMessage(hwnd, WM_SETTEXT, 0, uintptr(unsafe.Pointer(syscall.StringToUTF16Ptr(text)))) {
            return newError("WM_SETTEXT failed")
        }
        return nil
    }