C++GDI绘制直角坐标系,坐标原点在窗口中心,并绘制刻度,在第一象限绘制矩形并标注字母
时间: 2024-04-07 07:33:50 浏览: 21
可以使用C++的GDI(图形设备接口)来绘制直角坐标系,并在窗口中心设置坐标原点。以下是一个示例代码:
```cpp
#include <Windows.h>
LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam);
int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
{
// 创建窗口
const char *className = "MyWindowClass";
const char *windowTitle = "C++ GDI Demo";
int screenWidth = GetSystemMetrics(SM_CXSCREEN);
int screenHeight = GetSystemMetrics(SM_CYSCREEN);
int windowWidth = 800;
int windowHeight = 600;
int windowX = (screenWidth - windowWidth) / 2;
int windowY = (screenHeight - windowHeight) / 2;
WNDCLASSEX wc;
HWND hWnd;
MSG msg;
wc.cbSize = sizeof(WNDCLASSEX);
wc.style = CS_HREDRAW | CS_VREDRAW;
wc.lpfnWndProc = WndProc;
wc.cbClsExtra = 0;
wc.cbWndExtra = 0;
wc.hInstance = hInstance;
wc.hIcon = LoadIcon(NULL, IDI_APPLICATION);
wc.hCursor = LoadCursor(NULL, IDC_ARROW);
wc.hbrBackground = (HBRUSH)(COLOR_WINDOW + 1);
wc.lpszMenuName = NULL;
wc.lpszClassName = className;
wc.hIconSm = LoadIcon(NULL, IDI_APPLICATION);
if (!RegisterClassEx(&wc))
{
MessageBox(NULL, "窗口注册失败!", "错误", MB_ICONEXCLAMATION | MB_OK);
return 0;
}
hWnd = CreateWindowEx(
WS_EX_CLIENTEDGE,
className,
windowTitle,
WS_OVERLAPPEDWINDOW,
windowX,
windowY,
windowWidth,
windowHeight,
NULL,
NULL,
hInstance,
NULL);
if (hWnd == NULL)
{
MessageBox(NULL, "窗口创建失败!", "错误", MB_ICONEXCLAMATION | MB_OK);
return 0;
}
ShowWindow(hWnd, nCmdShow);
UpdateWindow(hWnd);
// 消息循环
while (GetMessage(&msg, NULL, 0, 0) > 0)
{
TranslateMessage(&msg);
DispatchMessage(&msg);
}
return msg.wParam;
}
LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
switch (message)
{
case WM_PAINT:
{
PAINTSTRUCT ps;
HDC hdc = BeginPaint(hWnd, &ps);
// 设置坐标原点在窗口中心
int windowWidth = ps.rcPaint.right - ps.rcPaint.left;
int windowHeight = ps.rcPaint.bottom - ps.rcPaint.top;
int centerX = windowWidth / 2;
int centerY = windowHeight / 2;
// 绘制坐标轴
MoveToEx(hdc, 0, centerY, NULL);
LineTo(hdc, windowWidth, centerY);
MoveToEx(hdc, centerX, 0, NULL);
LineTo(hdc, centerX, windowHeight);
// 绘制刻度
int scaleLength = 10;
int scaleGap = 50;
for (int x = centerX + scaleGap; x < windowWidth; x += scaleGap)
{
MoveToEx(hdc, x, centerY - scaleLength, NULL);
LineTo(hdc, x, centerY + scaleLength);
}
for (int x = centerX - scaleGap; x >= 0; x -= scaleGap)
{
MoveToEx(hdc, x, centerY - scaleLength, NULL);
LineTo(hdc, x, centerY + scaleLength);
}
for (int y = centerY + scaleGap; y < windowHeight; y += scaleGap)
{
MoveToEx(hdc, centerX - scaleLength, y, NULL);
LineTo(hdc, centerX + scaleLength, y);
}
for (int y = centerY - scaleGap; y >= 0; y -= scaleGap)
{
MoveToEx(hdc, centerX - scaleLength, y, NULL);
LineTo(hdc, centerX + scaleLength, y);
}
// 在第一象限绘制矩形并标注字母
RECT rect = {centerX, centerY, centerX + 100, centerY + 100};
DrawText(hdc, "A", 1, &rect, DT_CENTER | DT_VCENTER | DT_SINGLELINE);
EndPaint(hWnd, &ps);
break;
}
case WM_CLOSE:
{
DestroyWindow(hWnd);
break;
}
case WM_DESTROY:
{
PostQuitMessage(0);
break;
}
default:
{
return DefWindowProc(hWnd, message, wParam, lParam);
}
}
return 0;
}
```
上述代码创建了一个窗口,并在窗口中心绘制了直角坐标系。然后在第一象限绘制了一个矩形,并标注了字母"A"。你可以根据需要进一步修改和完善代码。