SDK编写简单的随机数生成器

上几天帮同学搞了一个随机数生成器，首先在网上搜索了一下，发现网上有的做的也比较的简单，但是功能还是比较全的。

而且发现自己学的东西刚好可以写一个随机数生成器。当然还有些预备知识没有学，所以现学现用了。

计时器的有关知识我已经了解了，首先要用到创建字体，然后是创建父窗口控件，然后就是利用RGB的颜色的变化了。

看了几天的书，终于写出来了。下面是代码：

#include <windows.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <string.h>

#define ID_TIMER 1

LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM) ;

int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
PSTR szCmdLine, int iCmdShow)
{
static TCHAR szAppName[] = TEXT ("Beeper1") ;
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 ("Program requires Windows NT!"),
szAppName, MB_ICONERROR) ;
return 0 ;
}

hwnd = CreateWindow (szAppName, TEXT ("随机数生成器1.00版本"),
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 ;
}

LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
static BOOL fFlipFlop = FALSE ;
static DWORD color_green = 255;
static DWORD color_blue = 255;
static DWORD color_red = 255;
LOGFONT lf;
HFONT hFont ;
TEXTMETRIC tm ;
TCHAR szBuffer [40];
static int cxChar, cyChar, sum;
DWORD a, iLength;
DWORD ownrand[40] = {31,24,17,11,5,22,4,7,1,32,15,39,29,3,27,21,38,25,12,33,9,23,36,2,13,18,30,16,26,34,37,10,8,28,19,6,14,20,35};
TCHAR str[256], type_height[10], type_width[10];
HBRUSH hBrush ;
HDC hdc ;
PAINTSTRUCT ps ;
RECT rc ;
HWND hwndButton;
switch (message)
{
case WM_CREATE:
SetTimer (hwnd, ID_TIMER, 50, NULL) ;
cxChar = LOWORD (GetDialogBaseUnits ()) ;
cyChar = HIWORD (GetDialogBaseUnits ()) ;
hwndButton = CreateWindow ( TEXT("button"),
TEXT("开始"),
WS_CHILD | WS_VISIBLE | BS_PUSHBUTTON,
cxChar + 420, cyChar * (1 + 2 * 1)+300,
20 * cxChar, 7 * cyChar / 4,
hwnd, (HMENU) 1,
((LPCREATESTRUCT) lParam)->hInstance, NULL) ;

hwndButton = CreateWindow ( TEXT("button"),
TEXT("暂停"),
WS_CHILD | WS_VISIBLE | BS_PUSHBUTTON,
cxChar + 420 , cyChar * (1 + 2 * 1)+350,
20 * cxChar, 7 * cyChar / 4,
hwnd, (HMENU) 2,
((LPCREATESTRUCT) lParam)->hInstance, NULL) ;
return 0 ;

case WM_TIMER :
sum++;
InvalidateRect (hwnd, NULL, FALSE) ;
return 0 ;

case WM_PAINT:

hdc = BeginPaint (hwnd, &ps) ;
GetClientRect (hwnd, &rc) ;
hBrush = CreateSolidBrush (RGB(color_red,color_green,color_blue));

if (sum<=39)
_itow(ownrand[sum],str,10);
else{
sum=0;
_itow(ownrand[sum],str,10);
}

color_red -= 10; //颜色变化的实现
color_green -= 5;
color_blue -= 1;
sum++;

FillRect (hdc, &rc, hBrush) ;
hdc = GetDC(hwnd);
GetTextMetrics(hdc,&tm);
cxChar = tm.tmAveCharWidth;
cyChar = tm.tmHeight + tm.tmExternalLeading;
iLength = wcslen(str);
SetTextColor(hdc,RGB(255-color_red,255-color_green,255-color_blue));
//SetTextColor(hdc,RGB(250,0,0));

//设置字体
lf.lfHeight = 200;
lf.lfWeight = 170;
lf.lfWeight = 700;
lf.lfUnderline = 0;
lf.lfStrikeOut = 0;
hFont = CreateFontIndirect(&lf);
SelectObject(hdc, hFont);
//GetTextMetrics (hdc, &tm);
//_itow(tm.tmHeight,type_height,10);
//_itow(tm.tmAscent,type_width,10);
//TextOut(hdc, 0, 0, type_height, wcslen(type_height));
//TextOut(hdc, 50, 0, type_width, wcslen(type_width));
DeleteObject (hFont);
SetBkColor (hdc, GetSysColor(COLOR_WINDOW));
TextOut(hdc, cxChar+400, cyChar+100, str, iLength);



ReleaseDC(hwnd, hdc);
EndPaint (hwnd, &ps) ;
DeleteObject (hBrush) ;
return 0 ;
case WM_COMMAND:
if (2 == wParam){
KillTimer (hwnd, ID_TIMER) ;
//MessageBox(hwnd, TEXT("恭喜您"),TEXT("congratulations"),MB_OK);
}

if (1 == wParam){
SetTimer (hwnd, ID_TIMER, 50, NULL) ;
}
break;
case WM_DESTROY :
KillTimer (hwnd, ID_TIMER) ;
PostQuitMessage (0) ;
return 0 ;
}
return DefWindowProc (hwnd, message, wParam, lParam) ;
}

关于随机数产生的问题，本来想用rand(time(0))来实现的，但是通过测试发现精度不够高，当timer调用每100毫秒更新一次的时候就已经显现出伪随机特性了。

本来想自己写一个随机数生成算法的，但是由于滚动的总数量不是很多，所以请教了华哥，自己开了一个数组，在里面随机写了30个数字。

关于颜色的变化的实现，关键代码其实也比较简单的，每次调用计时器的时候改变RGB的值，但是改变的值不一样，这样就加长了循环周期。

整个代码只是基本实现了效果，没有过多的功能，自己如果以后学了·鼠标键盘等一些其他东西的话还能把这些东西也加进去，做一个改进版本。