一般情況下多線程編程多采用MFC類庫實現(xiàn),那么如果不使用MFC 如何進(jìn)行多線程程序設(shè)計呢?本文將就這個問題進(jìn)行討論: 微軟在Windows API中提供了建立新的線程的函數(shù)CreateThread,它的語法如下:
hThread = CreateThread (&security_attributes, dwStackSize, ThreadProc,pParam, dwFlags, &idThread) ; |
第一個參數(shù)是指向SECURITY_ATTRIBUTES型態(tài)的結(jié)構(gòu)的指針。在Windows 98中忽略該參數(shù)。在Windows NT中,它被設(shè)為NULL。第二個參數(shù)是用于新線程的初始堆棧大小,默認(rèn)值為0。在任何情況下,Windows根據(jù)需要動態(tài)延長堆棧的大小。 CreateThread的第三個參數(shù)是指向線程函數(shù)的指標(biāo)。函數(shù)名稱沒有限制,但是必須以下列形式聲明:
DWORD WINAPI ThreadProc (PVOID pParam) ; |
CreateThread的第四個參數(shù)為傳遞給ThreadProc的參數(shù)。這樣主線程和從屬線程就可以共享數(shù)據(jù)。 CreateThread的第五個參數(shù)通常為0,但當(dāng)建立的線程不馬上執(zhí)行時為旗標(biāo)CREATE_SUSPENDED。線程將暫停直到呼叫ResumeThread來恢復(fù)線程的執(zhí)行為止。第六個參數(shù)是一個指標(biāo),指向接受執(zhí)行緒ID值的變量。 大多數(shù)Windows程序?qū)懽髡呦矚g用在PROCESS.H表頭文件中聲明的C執(zhí)行時期鏈接庫函數(shù)_beginthread。它的語法如下:
hThread = _beginthread (ThreadProc, uiStackSize, pParam) ; |
它更簡單,對于大多數(shù)應(yīng)用程序很完美,這個線程函數(shù)的語法為:
void __cdecl ThreadProc (void * pParam) ; |
在建立多線程的Windows程序時,需要在「Project Settings」對話框中做一些修改。選擇「C/C++」頁面標(biāo)簽,然后在「Category」下拉式清單方塊中選擇「Code Generation」。在「Use Run-Time Library」下拉式清單方塊中,可以看到用于「Release」設(shè)定的「Single-Threaded」和用于Debug設(shè)定的「Debug Single-Threaded」。將這些分別改為「Multithreaded」和「Debug Multithreaded」。這將把編譯器旗標(biāo)改為/MT,它是編譯器在編譯多線程的應(yīng)用程序所需要的。 第一個demo.
/******************************************************* * * deom1---四個線程同時寫一個文件( 沒有參數(shù) ) * * ***********************************************************/ #include <windows.h> #include <process.h> /* _beginthread, _endthread */ #include <iostream> #include <fstream> using namespace std;
ofstream out("out.txt");
void ThreadFunc1(PVOID param) { while(1) { Sleep(10); out<<"This was draw by thread l"<<endl; } } void ThreadFunc2(PVOID param) { while(1) { Sleep(10); out<<"This was draw by thread 2"<<endl; } } void ThreadFunc3(PVOID param) { while(1) { Sleep(10); out<<"This was draw by thread 3"<<endl; } } void ThreadFunc4(PVOID param) { while(1) { Sleep(10); out<<"This was draw by thread 4"<<endl; } } int main() { int i=0; _beginthread(ThreadFunc1,0,NULL); _beginthread(ThreadFunc2,0,NULL);
_beginthread(ThreadFunc3,0,NULL); _beginthread(ThreadFunc4,0,NULL); Sleep(3000); out<<"end"; return 0; }
//demo1 end-----------------------------------------------
第二個demo. /******************************************************* * * deom2---四個線程同時寫一個文件( 有參數(shù) ) * * ***********************************************************/ #include <windows.h> #include <process.h> /* _beginthread, _endthread */ #include <iostream> #include <fstream> #include <string> using namespace std; ofstream out("out.txt");
void ThreadFunc1(PVOID param) { while(1) { char *p; p=(char *) param; Sleep(10); out<<p<<"This was draw by thread l"<<endl; } } void ThreadFunc2(PVOID param) { while(1) { Sleep(10); out<<"This was draw by thread 2"<<endl; } } void ThreadFunc3(PVOID param) { while(1) { Sleep(10); out<<"This was draw by thread 3"<<endl; } } void ThreadFunc4(PVOID param) { while(1) { Sleep(10); out<<"This was draw by thread 4"<<endl; } } int main() { char *pstr=" 參數(shù)傳遞成功";
_beginthread(ThreadFunc1,0,pstr); _beginthread(ThreadFunc2,0,NULL);
_beginthread(ThreadFunc3,0,NULL); _beginthread(ThreadFunc4,0,NULL); Sleep(1000); out<<"end"; return 0; }
// demo2 end ------------------------------------------------
第三個demo( 一個win32 應(yīng)用程序 )
/******************************************************* * * deom3--- 在屏幕上隨機畫出一系列矩形 * * ***********************************************************/
#include <windows.h> #include <process.h>
LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM) ; HWND hwnd ;
int cxClient, cyClient ;
int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
PSTR szCmdLine, int iCmdShow) { static TCHAR szAppName[] = TEXT ("RndRctMT") ; MSG msg ;
WNDCLASS wndclass ;
wndclass.style = CS_HREDRAW | CS_VREDRAW ; wndclass.lpfnWndProc = WndProc ; wndclass.cbClsExtra = 0 ; wndclass.cbWndExtra = 0 ; wndclass.hInstance = hInstance ; wndclass.hIcon = LoadIcon (NULL, IDI_APPLICATION) ; wndclass.hCursor = LoadCursor (NULL, IDC_ARROW) ; wndclass.hbrBackground = (HBRUSH) GetStockObject (WHITE_BRUSH) ; wndclass.lpszMenuName = NULL ; wndclass.lpszClassName = szAppName ;
if (!RegisterClass (&wndclass)) { MessageBox (NULL, TEXT ("This program requires Windows NT!"),szAppName, MB_ICONERROR) ; return 0 ; }
hwnd = CreateWindow ( szAppName, TEXT ("Random Rectangles"), WS_OVERLAPPEDWINDOW, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT, NULL, NULL, hInstance, NULL) ; ShowWindow (hwnd, iCmdShow) ; UpdateWindow (hwnd) ;
while (GetMessage (&msg, NULL, 0, 0)) { TranslateMessage (&msg) ; DispatchMessage (&msg) ; } return msg.wParam ; }
VOID Thread (PVOID pvoid) { HBRUSH hBrush ; HDC hdc ; int xLeft, xRight, yTop, yBottom, iRed, iGreen, iBlue ;
while (TRUE) { if (cxClient != 0 || cyClient != 0) { xLeft = rand () % cxClient ; xRight = rand () % cxClient ; yTop = rand () % cyClient ; yBottom = rand () % cyClient ; iRed = rand () & 255 ; iGreen = rand () & 255 ; iBlue = rand () & 255 ; hdc = GetDC (hwnd) ; hBrush = CreateSolidBrush (RGB (iRed, iGreen, iBlue)) ; SelectObject (hdc, hBrush) ;
Rectangle (hdc,min (xLeft, xRight), min (yTop, yBottom), max (xLeft, xRight), max (yTop, yBottom)) ;
ReleaseDC (hwnd, hdc) ; DeleteObject (hBrush) ; } } }
LRESULT CALLBACK WndProc ( HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam) { switch (message) { case WM_CREATE: _beginthread (Thread, 0, NULL) ; return 0 ; case WM_SIZE: cxClient = LOWORD (lParam) ; cyClient = HIWORD (lParam) ; return 0 ; case WM_DESTROY: PostQuitMessage (0) ; return 0 ; } return DefWindowProc (hwnd, message, wParam, lParam) ; }
//demo4 end-----------------------------------------------
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參考:windows 程序設(shè)計
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