问题描述
- 求大神指教这个程序错在哪
-
[cpp] view plaincopyprint?
//#include "stdafx.h"#include
#include
#include
//#pragma comment(/Entry:WinMain)
#define ID_TIMER 1
#define SNOWNUM 500 // 雪花数量
#define CONTRAST 50 // 对比度
#define YSTART 5 // 用于确定雪花初始时的y坐标
#define SNOWCR RGB(0xFF, 0xFF, 0xFF) //雪花的颜色—白色
#define SNOWGATHERCR RGB(0xDB, 0xDB, 0xFF) //堆积雪花的颜色
typedef struct tagSnow
{
POINT ptSnowsPos[SNOWNUM]; //用于保存各个雪花的坐标
COLORREF crOrg[SNOWNUM]; //用于画雪花前屏幕原来的颜色
int iVx, iVy, iAllVx, iAllVy;
}Snow;
void initSnow(HDC hdc, Snow *sn, int iSnow, int cxScreen);
int GetContrast(HDC hdc, Snow *sn, int iSnow);
void drawSnow(HDC hdc, Snow *sn, int cxScreen);
LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM) ;
int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
PSTR szCmdLine, int iCmdShow)
{
static TCHAR szAppName[] = TEXT ("clsDeskSnow") ;
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 (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 ("桌面下雪"), WS_MINIMIZEBOX | WS_SYSMENU, CW_USEDEFAULT, CW_USEDEFAULT, 240, 120, NULL, NULL, hInstance, NULL) ; ShowWindow (hwnd, iCmdShow) ; UpdateWindow (hwnd) ; while (GetMessage (&msg, NULL, 0, 0)) { TranslateMessage (&msg) ; DispatchMessage (&msg) ; } return msg.wParam ;}
LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
HDC hdc ;
PAINTSTRUCT ps ;
RECT rect ;
static int cxScreen, cyScreen; //屏幕宽高度(单位:像素)
static int iTimes, iLoopTimes=100;
static Snow snowDream;
int i;
switch (message) { case WM_CREATE: cxScreen = GetSystemMetrics (SM_CXSCREEN) ; cyScreen = GetSystemMetrics (SM_CYSCREEN) ; srand ((int) GetCurrentTime ()) ; //初始化随机数发生器 snowDream.iAllVx = (unsigned)rand()%3 - 1; //雪花总体水平飘行速度(-1,0,1) snowDream.iAllVy = (unsigned)rand()%2 + 1; //雪花总体垂直下落速度(1,2) hdc = GetDC(NULL); //检索整个屏幕的设备上下文环境 for(i=0; i <SNOWNUM; i++) { snowDream.ptSnowsPos[i].x = rand() % cxScreen; //一个雪花开始下落的x坐标 snowDream.ptSnowsPos[i].y = rand() % YSTART; //一个雪花开始下落的y坐标 snowDream.crOrg[i] = GetPixel(hdc, snowDream.ptSnowsPos[i].x, snowDream.ptSnowsPos[i].y); //获取给定点的原来的颜色值 } ReleaseDC(NULL, hdc); SetTimer(hwnd, ID_TIMER, 10, NULL); //定时器，10毫秒 return 0 ; case WM_DISPLAYCHANGE: //当显示分辨率改变的时候 cxScreen = GetSystemMetrics (SM_CXSCREEN) ; cyScreen = GetSystemMetrics (SM_CYSCREEN) ; return 0; case WM_TIMER: hdc = GetDC(NULL); //检索整个屏幕的设备上下文环境 if(iTimes > iLoopTimes) { iTimes = 0; iLoopTimes = 50 + (unsigned)rand()%50; if(snowDream.iAllVx != 0) snowDream.iAllVx = 0; else snowDream.iAllVx = (unsigned)rand()%3 - 1; //雪花总体水平飘行速度(-1,0,1) snowDream.iAllVy = (unsigned)rand()%2 + 1; //雪花总体垂直下落速度(1,2) } else iTimes++; drawSnow(hdc, &snowDream, cxScreen); ReleaseDC(NULL, hdc); return 0; case WM_PAINT: hdc = BeginPaint (hwnd, &ps) ; GetClientRect (hwnd, &rect) ; DrawText (hdc, TEXT ("桌面下雪!"), -1, &rect, DT_SINGLELINE | DT_CENTER | DT_VCENTER) ; EndPaint (hwnd, &ps) ; return 0 ; case WM_DESTROY: KillTimer(hwnd, ID_TIMER); // 中止定时器 InvalidateRect(NULL, NULL, TRUE); // 刷新桌面 PostQuitMessage (0) ; return 0 ; } return DefWindowProc (hwnd, message, wParam, lParam) ;}
void initSnow(HDC hdc, Snow *sn, int iSnow, int cxScreen) //初始化第iSnow个雪花
{
sn->ptSnowsPos[iSnow].x = (unsigned)rand() % cxScreen; //x范围整个屏幕宽
sn->ptSnowsPos[iSnow].y = (unsigned)rand() % YSTART; //y范围离屏幕顶部YSTART像素点以内
sn->crOrg[iSnow] = GetPixel(hdc, sn->ptSnowsPos[iSnow].x,
sn->ptSnowsPos[iSnow].y ) ;//获取给定点的原来的颜色值
}
int GetContrast(HDC hdc, Snow *sn, int iSnow)
{
int iR, iG, iB;
COLORREF crCmp;
if(0 == sn->iVx) //若水平速度为0，则取比其大一个像素的正下方的点
crCmp = GetPixel(hdc, sn->ptSnowsPos[iSnow].x, sn->ptSnowsPos[iSnow].y + 1);
else //若水平速度>0，取右下方的点。
crCmp = GetPixel(hdc, sn->ptSnowsPos[iSnow].x + (sn->iVx>0?1:-1), sn->ptSnowsPos[iSnow].y + 1);if(crCmp==SNOWCR) //如果为雪花的颜色
return 0;
//分别获取crCmp与对比点的蓝、绿、红部分的差值
iB = abs((crCmp>>16)&0xFF - (sn->crOrg[iSnow]>>16)&0xFF);
iG = abs((crCmp>>8)&0xFF - (sn->crOrg[iSnow]>>8)&0xFF);
iR = abs((crCmp)&0xFF - (sn->crOrg[iSnow])&0xFF);
return (iR+iG+iB)/3;
}
void drawSnow(HDC hdc, Snow *sn, int cxScreen)
{
int i;
for(i=0; i
{
//如果保存的原来的颜色不是雪花的颜色
if(sn->crOrg[i] != SNOWCR)SetPixel(hdc, sn->ptSnowsPos[i].x, sn->ptSnowsPos[i].y,
sn->crOrg[i]); //还原上一个位置的颜色
sn->iVx = sn->iAllVx*(i%3+1); //雪花的x飘动速度 sn->iVy = sn->iAllVy*(i%3+1); //雪花的y飘动速度 //rand()%5-2使雪花下落的时候 有抖动效果 sn->ptSnowsPos[i].x += sn->iVx+rand()%5-2; //雪花的下一个x坐标 sn->ptSnowsPos[i].y += sn->iVy+1; //雪花的下一个y坐标 //获取给定点的原来的颜色值 sn->crOrg[i] = GetPixel(hdc, sn->ptSnowsPos[i].x, sn->ptSnowsPos[i].y); if(CLR_INVALID == sn->crOrg[i]) //如果获取颜色失败,即雪花飘出了屏幕 { initSnow(hdc, sn, i, cxScreen); //重新初始化 雪花 continue; } if(sn->crOrg[i] != SNOWCR) //若当前点的颜色 不等于 雪花的颜色 { if(SNOWGATHERCR == sn->crOrg[i]) //当前点的颜色=堆积的雪的颜色 { //设置为雪花的颜色 SetPixel(hdc, sn->ptSnowsPos[i].x, sn->ptSnowsPos[i].y, SNOWCR); sn->crOrg[i] = SNOWCR; //initSnow(hdc, sn, i, cxScreen); //重新初始化 雪花 } else if(GetContrast(hdc, sn, i) > 50) //若对比度>50 { //堆积雪花 SetPixel(hdc, sn->ptSnowsPos[i].x, sn->ptSnowsPos[i].y, SNOWGATHERCR); SetPixel(hdc, sn->ptSnowsPos[i].x-1, sn->ptSnowsPos[i].y+1, SNOWGATHERCR); SetPixel(hdc, sn->ptSnowsPos[i].x+1, sn->ptSnowsPos[i].y+1, SNOWGATHERCR); initSnow(hdc, sn, i, cxScreen); //重新初始化 雪花 } else //对比度 <50,不堆积,画出这帧雪花.等下次的时候再还原此点原本的颜色.以产生飘动效果 SetPixel(hdc, sn->ptSnowsPos[i].x, sn->ptSnowsPos[i].y, SNOWCR); }}
}