下面的代码是介绍如何在windows平台发消息到非UI线程.
主要是'PeekMessage || GetMessage' 这两个API的应用. 当他们被调用的时候，如果当前线程还没有消息循环，就会创建一个.
利用这个特性比自己手动的去创建一个消息循环要方便得多.
发消息主要是使用线程PostThreadMessage
- #include <iostream>
- #include <string>
- #include "cassert"
- #include "windows.h"
- #include "process.h"
- enum { MSG_TEST = WM_USER+100,MSG_EXIT };
- unsigned __stdcall fun(void *param)
- {
- MSG msg;
- while(true)
- {
- if(GetMessage(&msg,0,0,0)) //get msg from message queue
- {
- char * info = reinterpret_cast<char*>(msg.wParam);
- bool keep_in_loop = true;
- switch(msg.message)
- {
- case MSG_TEST:
- std::cout << info << std::endl;
- break;
- case MSG_EXIT:keep_in_loop=false;
- std::cout << info << std::endl;
- break;
- default: break;
- }
- if ( ! keep_in_loop )
- {
- break;
- }
- }
- }
- std::cout << "out of loop" << std::endl;
- return 0;
- }
- void main()
- {
- HANDLE hThread;
- unsigned nThreadID;
- //start thread
- hThread = (HANDLE)_beginthreadex( NULL, 0, &fun, NULL, 0, &nThreadID );
- while(true)
- {
- UINT Msg = MSG_TEST;
- const char * p = "MSG_TEST";
- std::string commond;
- std::cin >> commond;
- if ( commond == "exit" )
- {
- Msg = MSG_EXIT;
- }
- BOOL bPostOK = PostThreadMessage(nThreadID,Msg,(WPARAM)p,0);
- if ( ! bPostOK )
- {
- assert( false );
- // the post event is to too early, please build msg loop first
- // 'PeekMessage || GetMessage' will forced to build the msg loop, if it does not exist.
- }
- }
- }