本文例項為大家分享了C++實現數字雨效果的具體程式碼，供大家參考，具體內容如下

#include <windows.h> 
 
#define ID_TIMER  1 
#define STRMAXLEN 25 //一個顯示列的最大長度 
#define STRMINLEN 8 //一個顯示列的最小長度 
 
LRESULT CALLBACK WndProc (HWND,UINT,WPARAM,LPARAM) ; 
// 
// 
typedef struct tagCharChain //整個當作螢幕的一個顯示列,這是個雙向列表 
{ 
    struct tagCharChain *prev; //連結串列的前個元素 
    TCHAR ch;         //一個顯示列中的一個字元 
    struct tagCharChain *next; //連結串列的後個元素 
}CharChain,*pCharChain; 
 
typedef struct tagCharColumn 
{ 
    CharChain *head,*current,*point; 
    int x,y,iStrLen; //顯示列的開始顯示的x,y座標,iStrLen是這個列的長度 
    int iStopTimes,iMustStopTimes; //已經停滯的次數和必須停滯的次數,必須停滯的次數是隨機的 
}CharColumn,*pCharColumn; 
 
int main(HINSTANCE hInstance,HINSTANCE hPrevInstance,PSTR szCmdLine,int iCmdShow) 
{ 
    static TCHAR szAppName[] = TEXT ("matrix") ; 
    HWND      hwnd ; 
    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 (BLACK_BRUSH) ; 
    wndclass.lpszMenuName    = NULL ; 
    wndclass.lpszClassName    = szAppName ; 
 
    if(!RegisterClass (&wndclass)) 
    { 
        MessageBox (NULL,TEXT ("此程式必須執行在NT下!"),szAppName,MB_ICONERROR) ; 
        return 0; 
    } 
 
    hwnd = CreateWindow (szAppName,NULL,WS_DLGFRAME | WS_THICKFRAME | WS_POPUP,GetSystemMetrics(SM_CXSCREEN),GetSystemMetrics(SM_CYSCREEN),hInstance,NULL) ; 
 
    ShowWindow (hwnd,SW_SHOWMAXIMIZED) ; //最大化顯示 
    UpdateWindow (hwnd) ; 
    ShowCursor(FALSE); //隱藏滑鼠游標 
 
    srand ((int) GetCurrentTime ()) ; //初始化隨機數發生器 
    while (GetMessage (&msg,0)) 
    { 
        TranslateMessage (&msg) ; 
        DispatchMessage (&msg) ; 
    } 
    ShowCursor(TRUE); //顯示滑鼠游標 
    return msg.wParam ; 
} 
 
TCHAR randomChar() //隨機字元產生函式 
{ 
    return (TCHAR)(rand()%2+48); //字元0或1
} 
 
int init(CharColumn *cc,int cyScreen,int x) //初始化 
{ 
    int j; 
    cc->iStrLen = rand()%(STRMAXLEN-STRMINLEN) + STRMINLEN; //顯示列的長度 
    cc->x = x+3 ;    //顯示列的開始顯示的x座標 
    cc->y =rand()%3?rand()%cyScreen:0; //顯示列的開始顯示的y座標 
    cc->iMustStopTimes = rand()%6 ; 
    cc->iStopTimes  = 0 ; 
    cc->head = cc->current = 
        (pCharChain)calloc(cc->iStrLen,sizeof(CharChain)); //生成顯示列 
    for(j=0; j<cc->iStrLen-1; j++) 
    { 
        cc->current->prev = cc->point; //cc->point一個顯示列的前個元素 
        cc->current->ch = '\0'; 
        cc->current->next = cc->current+1; //cc->current+1一個顯示列的後個元素 
        cc->point     = cc->current++; //cc->point = cc->current; cc->current++; 
    } 
    cc->current->prev = cc->point; //最後一個節點 
    cc->current->ch = '\0'; 
    cc->current->next = cc->head; 
    cc->head->prev  = cc->current; //頭節點的前一個為此鏈的最後一個元素 
 
    cc->current = cc->point = cc->head; //free掉申請的記憶體要用current當引數 
    cc->head->ch = randomChar(); // 對連結串列頭的 元素填充 
    return 0; 
} 
 
LRESULT CALLBACK WndProc (HWND hwnd,UINT message,WPARAM wParam,LPARAM lParam) 
{ 
    HDC     hdc ; 
    //ctn 用來確定一個顯示鏈是否 向下前進,如果等待次數超過必須等待的次數,ctn就代表要向下前進 
    int i,j,temp,ctn; //j為一個顯示鏈中除連結串列頭外的在螢幕上顯示的y座標,temp綠色過度到黑色之用 
    static HDC hdcMem; 
    HFONT  hFont; 
    static HBITMAP hBitmap; 
    static int cxScreen,cyScreen; //螢幕的寬度 高度. 
    static int iFontWidth=10,iFontHeight=15,iColumnCount; //字型的寬度 高度,列數 
    static CharColumn *ccChain; 
 
    switch (message) 
    { 
    case WM_CREATE: 
        cxScreen = GetSystemMetrics(SM_CXSCREEN) ; //螢幕寬度 
        cyScreen = GetSystemMetrics(SM_CYSCREEN) ; 
        SetTimer (hwnd,ID_TIMER,10,NULL) ; 
 
        hdc = GetDC(hwnd); 
        hdcMem = CreateCompatibleDC(hdc); 
        hBitmap = CreateCompatibleBitmap(hdc,cxScreen,cyScreen); 
        SelectObject(hdcMem,hBitmap); 
        ReleaseDC(hwnd,hdc); 
        //建立字型 
        hFont = CreateFont(iFontHeight,iFontWidth-5,FW_BOLD,DEFAULT_CHARSET,OUT_DEFAULT_PRECIS,CLIP_DEFAULT_PRECIS,DRAFT_QUALITY,FIXED_PITCH | FF_SWISS,TEXT("Fixedsys")); 
        SelectObject(hdcMem,hFont); 
        DeleteObject (hFont) ; 
        SetBkMode(hdcMem,TRANSPARENT); //設定背景模式為 透明 
        iColumnCount = cxScreen/(iFontWidth*3/2); //螢幕所顯示字母雨的列數 
 
        ccChain = (pCharColumn)calloc(iColumnCount,sizeof(CharColumn)); 
        for(i=0; i<iColumnCount; i++) 
        { 
            init(ccChain+i,cyScreen,(iFontWidth*3/2)*i); 
        } 
        return 0 ; 
 
    case WM_TIMER: 
        hdc = GetDC(hwnd); 
        PatBlt (hdcMem,BLACKNESS) ; //將記憶體裝置映像刷成黑色 
        for(i=0; i<iColumnCount; i++) 
        { 
            ctn = (ccChain+i)->iStopTimes++ > (ccChain+i)->iMustStopTimes; 
            // 
            (ccChain+i)->point = (ccChain+i)->head; //point用於遍歷整個顯示列 
 
            //第一個字元顯示為 白色 
            SetTextColor(hdcMem,RGB(255,255,255)); 
            TextOut(hdcMem,(ccChain+i)->x,(ccChain+i)->y,&((ccChain+i)->point->ch),1); 
            j = (ccChain+i)->y; 
            (ccChain+i)->point = (ccChain+i)->point->next; 
            //遍歷整個顯示列,將這個顯示列裡的字元從下往上顯示 
            temp = 0 ; //temp綠色過度到黑色之用 
            while((ccChain+i)->point != (ccChain+i)->head && (ccChain+i)->point->ch) 
            { 
                SetTextColor(hdcMem,RGB(0,255-(255*(temp++)/(ccChain+i)->iStrLen),0)); 
                TextOut(hdcMem,j-=iFontHeight,1); 
                (ccChain+i)->point = (ccChain+i)->point->next; 
            } 
            if(ctn) 
                (ccChain+i)->iStopTimes = 0 ; 
            else continue; 
            (ccChain+i)->y += iFontHeight; //下次開始顯示的y座標 為當前的y座標加上 一個字元的高度 
            //如果開始顯示的y座標減去 整個顯示列的長度超過了螢幕的高度 
            if( (ccChain+i)->y-(ccChain+i)->iStrLen*iFontHeight > cyScreen) 
            { 
                free( (ccChain+i)->current ); 
                init(ccChain+i,(iFontWidth*3/2)*i); 
            } 
            //連結串列的頭 為此連結串列的前個元素,因為下次開始顯示的時候 就相當與在整個顯示列的開頭添加個元素,然後在開始往上顯示 
            (ccChain+i)->head = (ccChain+i)->head->prev; 
            (ccChain+i)->head->ch = randomChar(); 
        } 
 
        BitBlt(hdc,hdcMem,SRCCOPY); 
        ReleaseDC(hwnd,hdc); 
        return 0; 
 
    case WM_RBUTTONDOWN: 
        KillTimer (hwnd,ID_TIMER) ; 
        return 0; 
 
    case WM_RBUTTONUP: 
        SetTimer (hwnd,NULL) ; 
        return 0; 
 
        //處理善後工作 
    case WM_KEYDOWN: 
    case WM_LBUTTONDOWN: 
    case WM_DESTROY: 
        KillTimer (hwnd,ID_TIMER) ; 
        DeleteObject(hBitmap); 
        DeleteDC(hdcMem); 
        for(i=0; i<iColumnCount; i++) 
        { 
            free( (ccChain+i)->current ); 
        } 
        free(ccChain); 
        PostQuitMessage (0) ; 
        return 0 ; 
    } 
    return DefWindowProc (hwnd,message,wParam,lParam) ; 
}

以上就是本文的全部內容，希望對大家的學習有所幫助，也希望大家多多支援我們。