Question

vc++中的图像处理

我目前只学了C语言，而且所用的编程软件是VC++，现在想在vc++里用C语言编个有关画直线，矩形的程序！不知道vc++里的有没现成的库函数（记得我只会C语言），如果没的话，帮忙写个，谢过各位大侠～
直接给一个可以运行的程序吧！包括头文件和源程序！

Answer 1

当然有现成的函数了。

//画矩形
Rectangle (hdc, cxClient / 8, cyClient / 8,
7 * cxClient / 8, 7 * cyClient / 8) ;

//画线
MoveToEx (hdc, 0, 0, NULL) ;
LineTo (hdc, cxClient, cyClient) ;

//画线
MoveToEx (hdc, 0, cyClient, NULL) ;
LineTo (hdc, cxClient, 0) ;

//画椭圆
Ellipse (hdc, cxClient / 8, cyClient / 8,
7 * cxClient / 8, 7 * cyClient / 8) ;

//画圆角矩形
RoundRect (hdc, cxClient / 4, cyClient / 4,
3 * cxClient / 4, 3 * cyClient / 4,
cxClient / 4, cyClient / 4) ;

Answer 2

得到设备环境
POINT pt0,pt1;
HDC hdc=GetWindowDC(hWnd);
MoveToEx(hdc,pt0,0);
LineTo(hdc,pt1);

如果有msdn，搜索下就有帮助

Answer 3

随便的书上都有

Answer 4

看这段代码：

#include <windows.h>

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

int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
PSTR szCmdLine, int iCmdShow)
{
//创建窗口
static TCHAR szAppName[] = TEXT ("LineDemo") ;
HWND hwnd ;
MSG msg ;
WNDCLASS wndclass ;

//窗口风格设置
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 ;

//注册窗口类
if (!RegisterClass (&wndclass))
{
MessageBox (NULL, TEXT ("Program requires Windows NT!"),
szAppName, MB_ICONERROR) ;
return 0 ;
}

//创建窗口
hwnd = CreateWindow (szAppName, TEXT ("Line Demonstration"),
WS_OVERLAPPEDWINDOW,
CW_USEDEFAULT, CW_USEDEFAULT,
CW_USEDEFAULT, CW_USEDEFAULT,
NULL, NULL, hInstance, NULL) ;

//显示窗口
ShowWindow (hwnd, iCmdShow) ;
UpdateWindow (hwnd) ;

//消息循环
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 int cxClient, cyClient ;
HDC hdc ;
PAINTSTRUCT ps ;

switch (message)
{
case WM_SIZE://窗口改变大小时，获得客户区长宽
cxClient = LOWORD (lParam) ;
cyClient = HIWORD (lParam) ;
return 0 ;

case WM_PAINT:
hdc = BeginPaint (hwnd, &ps) ;//指定更新区域

//画矩形
Rectangle (hdc, cxClient / 8, cyClient / 8,
7 * cxClient / 8, 7 * cyClient / 8) ;

//画线
MoveToEx (hdc, 0, 0, NULL) ;
LineTo (hdc, cxClient, cyClient) ;

//画线
MoveToEx (hdc, 0, cyClient, NULL) ;
LineTo (hdc, cxClient, 0) ;

//画椭圆
Ellipse (hdc, cxClient / 8, cyClient / 8,
7 * cxClient / 8, 7 * cyClient / 8) ;

//画圆角矩形
RoundRect (hdc, cxClient / 4, cyClient / 4,
3 * cxClient / 4, 3 * cyClient / 4,
cxClient / 4, cyClient / 4) ;

EndPaint (hwnd, &ps) ;
return 0 ;

case WM_DESTROY:
PostQuitMessage (0) ;
return 0 ;
}
return DefWindowProc (hwnd, message, wParam, lParam) ;
}