在YC++中编写多线程代码

      在运行程序时，很多费时的操作或计算(如通过socket读网络文件, 解一个微分方程等等)，都有可能使界面失去反应，这种现象叫做阻塞。如何解决阻塞问题呢？最好的办法就是使用多线程。
      在YC++编程中，多线程程序是很容易编写的。编写多线程程序最重要的一条就是尽量使用局部变量，
而不要使用全局变量(只读的除外)。因为使用全局变量容易出错。

/*****************************************************************************************************************/
下面这个例子用Win32函数CreateThread创建线程, 其用法是:

将下列代码存入名字任取的文件, 如: th.cpp
在yc++中, 用 <文件 打开或创建cpp源程序> 调入th.cpp, 再用 <工具 执行> 运行th.cpp
              或在dos中, 用 ycc th.cpp 生成 th.exe, 再运行th.exe
在vc++中, 用 cl th.cpp 生成 th.exe, 再运行th.exe

#ifndef YCC
#include       
#include        "include/ycapi.h"

#pragma         comment(lib, "gdi32.lib")
#pragma         comment(lib, "user32.lib")
#pragma         comment(lib, "yxbapi.lib")
#endif

int WINAPI WinMain(HINSTANCE hInstance,HINSTANCE hPrevInstance,LPSTR lpCmdLine,int nShowCmd)
{
    /创建主窗口. 用YC++的API函数创建, 它不需要注册.
    int WINAPI MainWndProc(HWND hwnd,UINT iMessage,UINT wParam,LONG lParam,void *pUserData);
    HWND hwnd = YXB_Window(MainWndProc,NULL,0,
      WS_OVERLAPPEDWINDOW | WS_CAPTION | WS_SYSMENU,
      "多线程",110,50,800,600,NULL,WT_WIN);

    MSG  msg;
    while(GetMessage(&msg,NULL,0,0))
      {
 TranslateMessage(&msg);
 DispatchMessage(&msg);
      }
    return 0;
}

int WINAPI MainWndProc(HWND hwnd,UINT iMessage,UINT wParam,LONG lParam,void *pUserData)
{
    static HANDLE linep_thread_handle,rectp_thread_handle;
    switch(iMessage)
      {
 case WM_DESTROY:
      TerminateThread(linep_thread_handle,0);
      CloseHandle(linep_thread_handle);
      TerminateThread(rectp_thread_handle,0);
      CloseHandle(rectp_thread_handle);
      PostQuitMessage(0);
      return FALSE;
 case WM_CREATE:
      DWORD   linep_thread_ret, rectp_thread_ret;
      void draw_linep(LPVOID *my_buf), draw_rectp(LPVOID *my_buf);
      linep_thread_handle = CreateThread(NULL,0,(LPTHREAD_START_ROUTINE)draw_linep,hwnd,0,&linep_thread_ret);
      rectp_thread_handle = CreateThread(NULL,0,(LPTHREAD_START_ROUTINE)draw_rectp,hwnd,0,&rectp_thread_ret);
      return FALSE;
 case WM_PAINT:
      PAINTSTRUCT ps;
      BeginPaint(hwnd, &ps);
      YIMG yimg;
      memset(&yimg,0,sizeof YIMG);
      yimg.hdc = ps.hdc;     //通过这个设置, 可以将窗口客户区当作一幅图象来操作
      RECT mRect;
      GetClientRect(hwnd, &mRect);
      YXB_ImageFill(&yimg, 0, 0, mRect.right, mRect.bottom, RGB(130,150,160));
      EndPaint(hwnd, &ps);
      return FALSE;
      }
    return DefWindowProc(hwnd,iMessage,wParam,lParam);
}

const int  mycolor[]={0xff7766,0xcc88ff,0x6688aa,0xcc9977,0x88ff11,0x779911,0xdd88aa,0x55ccff};

void draw_linep(LPVOID *my_buf)
{
static int xx0=388,yy0=200;

    HWND hwnd = (HWND)my_buf;
    HDC hdc = GetDC(hwnd);
    RECT mRect;
    GetClientRect(hwnd, &mRect);
    MoveToEx(hdc,0,0,NULL);
    for(int ii=0; ; ii++)
      {
 HPEN hPen = CreatePen(PS_SOLID, 3, mycolor[ii%8]);
 HPEN hpenSave = (HPEN)SelectObject (hdc, hPen);
 LineTo(hdc,xx0,yy0);
 xx0 = rand()*mRect.right/2/RAND_MAX;
 yy0 = rand()*mRect.bottom/RAND_MAX;
 SelectObject (hdc, hpenSave);
 DeleteObject(hPen);
 Sleep(10);
      }
    ReleaseDC(hwnd,hdc);
}

void draw_rectp(LPVOID *my_buf)
{
static int xx0=0,yy0=0;

    HWND hwnd = (HWND)my_buf;
    HDC hdc = GetDC(hwnd);
    RECT mRect;
    GetClientRect(hwnd, &mRect);
    for(int ii=0; ; ii++)
      {
 HBRUSH hbr = (HBRUSH)SelectObject(hdc,CreateSolidBrush(mycolor[ii%8]));
 PatBlt(hdc,xx0,yy0,30,30,PATCOPY);
 DeleteObject(SelectObject(hdc,hbr));
 xx0 = rand()*mRect.right/2/RAND_MAX + mRect.right/2;
 yy0 = rand()*mRect.bottom/RAND_MAX;
 Sleep(10);
      }
    ReleaseDC(hwnd,hdc);
}