unity3d 实现windows 消息

Windows Message in the Unity3D : WndProc

LRESULT CALLBACK SubWndProc(
 HWND hWnd, 
 UINT nMessage, 
 WPARAM wParam, LPARAM lParam); 
 
WNDPROC  gOldWndProc = NULL; 
HWND  gUnityWnd = NULL; 
 
#ifdef    __cplusplus
extern "C" {
#endif    /*    __cplusplus    */
 
 __declspec(dllexport) bool __stdcall init(HWND hWnd)
 {
  gOldWndProc =(WNDPROC)SetWindowLong(hWnd, GWL_WNDPROC, (LONG)SubWndProc);
  gUnityWnd =hWnd;
 
  if (gOldWndProc !=NULL)
   return true;
 
  return false;
 }
 
 __declspec(dllexport) void __stdcall release()
 {
  SetWindowLong(gUnityWnd, GWL_WNDPROC, (LONG)gOldWndProc);
  gOldWndProc =0;
  gUnityWnd =0;
 }
 
#ifdef    __cplusplus
}
#endif    /*    __cplusplus    */
 
 
LRESULT CALLBACK SubWndProc(
 HWND hWnd, 
 UINT nMessage, 
 WPARAM wParam, LPARAM lParam)
{
 switch(nMessage)
 {
  case WM_IME_SETCONTEXT:
  case WM_IME_STARTCOMPOSITION:
  case WM_IME_ENDCOMPOSITION:
  case WM_IME_COMPOSITION:
  case WM_IME_REQUEST:
   {
    //...
   }
   break;
 }
 return CallWindowProc(gOldWndProc, hWnd, nMessage, wParam, lParam);
}

Unity 可以透過呼叫 DLL 提供的 init() 函數，讓 Windows 改為呼叫我們指定的函數 (SubWndProc) 來處理 Message，透過 release() 函數讓 Message 處理流程復原。底下是 Unity 部分的原始碼（DLL 檔名為 UnityIMEDLL.dll 且檔案放在 Assets/Plugins 目錄下）

using UnityEngine;
 
using System;
using System.Collections;
using System.Collections.Generic;
using System.Runtime.InteropServices;
 
public class IMEInputBox : MonoBehaviour
{
    //-----------------------------------------------------------
    [DllImport("UnityIMEDLL")]
    protected static extern bool init(IntPtr hWnd);
 
    [DllImport("UnityIMEDLL")]
    protected static extern void release();
 
    [DllImport("user32")]
    protected static extern IntPtr GetActiveWindow();
 
    //-----------------------------------------------------------
 // Use this for initialization
 void Start ()
 {
        Debug.Log("init UnityIMEDLL.");
        try
        {
            init(GetActiveWindow());
        }
        catch (Exception e)
        {
            Debug.Log(e.ToString());
        }
 }
 
    void OnDisable()
    {
        Debug.Log("release UnityIMEDLL.");
        try
        {
            release();
        }
        catch (Exception e)
        {
            Debug.Log(e.ToString());
        }
    }
}