利用MoveToEx和LineTo画横线

MoveToEx

The MoveToEx function updates the current position to the specified point and optionally returns the previous position.

BOOL MoveToEx(  HDC hdc,          // handle to device context  int X,            // x-coordinate of new current position  int Y,            // y-coordinate of new current position  LPPOINT lpPoint   // old current position);

Parameters

hdc

[in] Handle to a device context.

X

[in] Specifies the x-coordinate, in logical units, of the new position, in logical units.

Y

[in] Specifies the y-coordinate, in logical units, of the new position, in logical units.

lpPoint

[out] Pointer to a POINT structure that receives the previous current position. If this parameter is a NULL pointer, the previous position is not returned.

Return Values

If the function succeeds, the return value is nonzero.

If the function fails, the return value is zero.

Windows NT/2000/XP: To get extended error information, call GetLastError.

LineTo

The LineTo function draws a line from the current position up to, but not including, the specified point.

BOOL LineTo(  HDC hdc,    // device context handle  int nXEnd,  // x-coordinate of ending point  int nYEnd   // y-coordinate of ending point);

Parameters

hdc

[in] Handle to a device context.

nXEnd

[in] Specifies the x-coordinate, in logical units, of the line's ending point.

nYEnd

[in] Specifies the y-coordinate, in logical units, of the line's ending point.

Return Values

If the function succeeds, the return value is nonzero.

If the function fails, the return value is zero.

Windows NT/2000/XP: To get extended error information, call GetLastError.

Remarks

LineTo.c

/* -------------------------------------------------------------------Author:邱于涵Time:2016年11月26日23:29:05--------------------------------------------------------------------*/#include <windows.h>LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, PSTR szCmdLine, int iCmdShow){static TCHAR szAppName[] = TEXT("MyWindows");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("这个程序需要在 Windows NT 才能执行！"), szAppName, MB_ICONERROR);return 0;}hwnd = CreateWindow(szAppName,TEXT("涵涵工作室"),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){HDC hdc;PAINTSTRUCT ps;RECT rect;switch (message){case WM_PAINT:hdc = GetDC(hwnd);MoveToEx(hdc, 100, 100, NULL);//MoveToEx的最后一个参数可以存放 上次的 坐标，//GetCurrentPositionEx  获得当前坐标LineTo(hdc, 600, 100);//LineTo画完后 坐标会跟着改变LineTo(hdc, 300, 300);ReleaseDC(hwnd, hdc);return 0;case WM_DESTROY:PostQuitMessage(0);return 0;}return DefWindowProc(hwnd, message, wParam, lParam);}

DrawGrid.c

/* -------------------------------------------------------------------Author:邱于涵Time:2016年11月27日00:01:25课后作业：要求绘制一个网格要求线与线之间距离 50px--------------------------------------------------------------------*/#include <windows.h>LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, PSTR szCmdLine, int iCmdShow){static TCHAR szAppName[] = TEXT("MyWindows");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("这个程序需要在 Windows NT 才能执行！"), szAppName, MB_ICONERROR);return 0;}hwnd = CreateWindow(szAppName,TEXT("涵涵工作室"),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){HDC hdc;PAINTSTRUCT ps;static RECT rect;int i;switch (message){case WM_SIZE://当窗体大小发生改变时候 这个WM_SIZE消息被发出hdc = GetDC(hwnd);GetClientRect(hwnd,&rect);ReleaseDC(hwnd, hdc);break;case WM_PAINT:hdc = GetDC(hwnd);//纵向线条for (i = 0; i < rect.right; i += 50){MoveToEx(hdc, i, 0, NULL);LineTo(hdc, i, rect.bottom);}//横向线条for (i = 0; i < rect.bottom; i += 50){MoveToEx(hdc, 0, i, NULL);LineTo(hdc, rect.right, i);}ReleaseDC(hwnd, hdc);break;case WM_DESTROY:PostQuitMessage(0);break;}return DefWindowProc(hwnd, message, wParam, lParam);}