golang调用dll的接口三种方式小结

dllpath:="test.dll"
handle:=syscall.NewLazyDLL(dllpath)
//引号中的init即为dll中的函数方法
init:=handle.NewProc("init")
init.Call(BytePtr("C:\\dll"))

func BytePtr(str string)uintptr{
    s:=[]byte(str)
    return uintptr(unsafe.Pointer(&s[0]))
}

func call_Init()*syscall.LazyDLL{
    dllpath:="test.dll"
    handle:=syscall.NewLazyDLL(dllpath)
    //引号中的init即为dll中的函数方法
    init:=handle.NewProc("init")
    init.Call(BytePtr("C:\\dll"))
    return handle
}

func Call_PassByValue(n int) error {
	dllPath := "E:\\Code\\vs2015_project\\demo\\x64\\Release\\c2plusdll.dll"
	handle := syscall.MustLoadDLL(dllPath)
	callByReference := handle.MustFindProc("callByReference")
	ret, _, err := callByReference.Call(IntPtr(n))
	if err != nil {
		fmt.Println("DllTestDef的运算结果为:", ret)
	}
	return nil
}

func IntPtr(n int)uintptr{
    return uintptr(n)
}

func get_ConnData()string{
    dllPath := "C:\\dll"
	handle, err := syscall.LoadLibrary(dllPath)
	if err != nil {
		fmt.Printf("Error: %s\n", err)
		return err
	}
	defer syscall.FreeLibrary(handle)

	export_conn, err := syscall.GetProcAddress(handle, "export_conn")
	if err != nil {
		fmt.Printf("Error: %s\n", err)
		return err
	}
	ret, _, _ := syscall.Syscall(export_conn, IntPtr("5"))
	if err != nil {
		fmt.Printf("Error: %s\n", err)
	}
	return uintptrTostr(ret)
}

func uintptrTostr(ptr uintptr)string{
    p:=(*byte)(unsafe.Pointer(ptr))
    data:=make([]byte,0)
    for *p!=0{
        data=append(data,*p)
        ptr+=unsafe.Sizeof(byte(0))
        p=(*byte)(unsafe.Pointer(ptr))
    }
    return string(data)
}