#include <windows.h>
#include <iostream>
using namespace std;
#define ID_DDA 9001
#define ID_MID 9002
#define ID_UNDO 9003
#define ID_REDO 9004
HPEN hPen;
PAINTSTRUCT ps ;
int firstX , firstY , lastX , lastY;
int numClicks = 0;
class algo
{
HWND hwnd;
int algorithm;
int x,y,size,sizeRemoved;
int *x1Data;
int *y1Data;
int *x2Data;
int *y2Data;
int *x1Removed;
int *y1Removed;
int *x2Removed;
int *y2Removed;
void Draw()
{
for (int i=0;i<size;i++)
{
if (algorithm == 0)
{
BeginPaint(hwnd , &ps );
hPen = CreatePen(PS_SOLID,3,RGB(0,0,255));
SelectObject(ps.hdc, hPen);
MoveToEx(ps.hdc, x1Data[i], y1Data[i], NULL);
LineTo(ps.hdc, x2Data[i], y2Data[i]);
EndPaint(hwnd , & ps);
}
else
{
BeginPaint(hwnd , &ps );
hPen = CreatePen(PS_SOLID,3,RGB(255,0,0));
SelectObject(ps.hdc, hPen);
MoveToEx(ps.hdc, x1Data[i], y1Data[i], NULL);
LineTo(ps.hdc, x2Data[i], y2Data[i]);
EndPaint(hwnd , & ps);
}
}
}
public:
algo(HWND hwnd)
{
this->hwnd = hwnd;
x1Data = new int [1];
y1Data = new int [1];
x2Data = new int [1];
y2Data = new int [1];
x1Removed = new int [1];
y1Removed = new int [1];
x2Removed = new int [1];
y2Removed = new int [1];
size=0;
sizeRemoved=0;
algorithm = 0;
}
void setHWND (HWND hwnd)
{
this->hwnd = hwnd;
}
void ChangeAlgo(int num)
{
algorithm = num;
size = 0;
sizeRemoved = 0;
int * tempx1 = new int [1];
int * tempy1 = new int [1];
int * tempx2 = new int [1];
int * tempy2 = new int [1];
int * tx1 = new int [1];
int * ty1 = new int [1];
int * tx2 = new int [1];
int * ty2 = new int [1];
x1Data = tempx1;
y1Data = tempy1;
x2Data = tempx2;
y2Data = tempy2;
x1Removed = tx1;
y1Removed = ty1;
x2Removed = tx2;
y2Removed = ty2;
}
int getAlgo ()
{
return algorithm;
}
void undo ()
{
x1Removed[sizeRemoved] = x1Data[size];
y1Removed[sizeRemoved] = y1Data[size];
x2Removed[sizeRemoved] = x2Data[size];
y2Removed[sizeRemoved] = y2Data[size];
sizeRemoved++;
int * tempx1 = new int [size];
int * tempy1 = new int [size];
int * tempx2 = new int [size];
int * tempy2 = new int [size];
for (int i=0;i<size;i++)
{
tempx1[i] = x1Data[i];
tempy1[i] = y1Data[i];
tempx2[i] = x2Data[i];
tempy2[i] = y2Data[i];
}
x1Data = tempx1;
y1Data = tempy1;
x2Data = tempx2;
y2Data = tempy2;
size--;
int * tx1 = new int [sizeRemoved + 1];
int * ty1 = new int [sizeRemoved + 1];
int * tx2 = new int [sizeRemoved + 1];
int * ty2 = new int [sizeRemoved + 1];
for (int i=0;i<sizeRemoved;i++)
{
tx1[i] = x1Removed[i];
ty1[i] = y1Removed[i];
tx2[i] = x2Removed[i];
ty2[i] = y2Removed[i];
}
x1Removed = tx1;
y1Removed = ty1;
x2Removed = tx2;
y2Removed = ty2;
Draw();
}
void redo ()
{
x1Data[size] = x1Removed[sizeRemoved - 1];
y1Data[size] = y1Removed[sizeRemoved - 1];
x2Data[size] = x2Removed[sizeRemoved - 1];
y2Data[size] = y2Removed[sizeRemoved - 1];
size++;
int * tempx1 = new int [size+1];
int * tempy1 = new int [size+1];
int * tempx2 = new int [size+1];
int * tempy2 = new int [size+1];
for (int i=0;i<size;i++)
{
tempx1[i] = x1Data[i];
tempy1[i] = y1Data[i];
tempx2[i] = x2Data[i];
tempy2[i] = y2Data[i];
}
tempx1 = x1Data;
tempy1 = y1Data;
tempx2 = x2Data;
tempy2 = y2Data;
int * tx1 = new int [sizeRemoved];
int * ty1 = new int [sizeRemoved];
int * tx2 = new int [sizeRemoved];
int * ty2 = new int [sizeRemoved];
for (int i=0;i<sizeRemoved;i++)
{
tx1[i] = x1Removed[i];
ty1[i] = y1Removed[i];
tx2[i] = x2Removed[i];
ty2[i] = y2Removed[i];
}
sizeRemoved--;
x1Removed = tx1;
y1Removed = ty1;
x2Removed = tx2;
y2Removed = ty2;
Draw();
}
void Draw (int x1, int y1 , int x2 , int y2)
{
BeginPaint(hwnd , &ps );
for (int i=0;i<size;i++)
{
if (algorithm == 0)
{
hPen = CreatePen(PS_SOLID,3,RGB(0,0,255));
SelectObject(ps.hdc, hPen);
MoveToEx(ps.hdc, x1Data[i], y1Data[i], NULL);
LineTo(ps.hdc, x2Data[i], y2Data[i]);
}
else
{
//BeginPaint(hwnd , &ps );
hPen = CreatePen(PS_SOLID,3,RGB(255,0,0));
SelectObject(ps.hdc, hPen);
MoveToEx(ps.hdc, x1Data[i], y1Data[i], NULL);
LineTo(ps.hdc, x2Data[i], y2Data[i]);
//EndPaint(hwnd , & ps);
}
}
if (algorithm == 0)
{
//BeginPaint(hwnd , &ps );
hPen = CreatePen(PS_SOLID,3,RGB(0,0,255));
SelectObject(ps.hdc, hPen);
MoveToEx(ps.hdc, x1, y1, NULL);
LineTo(ps.hdc, x2, y2);
//EndPaint(hwnd , & ps);
}
else
{
//BeginPaint(hwnd , &ps );
hPen = CreatePen(PS_SOLID,3,RGB(255,0,0));
SelectObject(ps.hdc, hPen);
MoveToEx(ps.hdc, x1, y1, NULL);
LineTo(ps.hdc, x2, y2);
//EndPaint(hwnd , & ps);
}
EndPaint(hwnd , & ps);
x1Data[size] = x1;
y1Data[size] = y1;
x2Data[size] = x2;
y2Data[size] = y2;
size++;
int * tempx1 = new int [size+1];
int * tempy1 = new int [size+1];
int * tempx2 = new int [size+1];
int * tempy2 = new int [size+1];
for (int i=0;i<size;i++)
{
tempx1[i] = x1Data[i];
tempy1[i] = y1Data[i];
tempx2[i] = x2Data[i];
tempy2[i] = y2Data[i];
}
tempx1 = x1Data;
tempy1 = y1Data;
tempx2 = x2Data;
tempy2 = y2Data;
}
};
/* Declare Windows procedure */
LRESULT CALLBACK WindowProcedure (HWND, UINT, WPARAM, LPARAM);
/* Make the class name into a global variable */
char szClassName[ ] = "WindowsApp";
int WINAPI WinMain (HINSTANCE hThisInstance,
HINSTANCE hPrevInstance,
LPSTR lpszArgument,
int nFunsterStil)
{
HWND hwnd; /* This is the handle for our window */
MSG messages; /* Here messages to the application are saved */
WNDCLASSEX wincl; /* Data structure for the windowclass */
/* The Window structure */
wincl.hInstance = hThisInstance;
wincl.lpszClassName = szClassName;
wincl.lpfnWndProc = WindowProcedure; /* This function is called by windows */
wincl.style = CS_DBLCLKS; /* Catch double-clicks */
wincl.cbSize = sizeof (WNDCLASSEX);
/* Use default icon and mouse-pointer */
wincl.hIcon = LoadIcon (NULL, IDI_APPLICATION);
wincl.hIconSm = LoadIcon (NULL, IDI_APPLICATION);
wincl.hCursor = LoadCursor (NULL, IDC_ARROW);
wincl.lpszMenuName = NULL; /* No menu */
wincl.cbClsExtra = 0; /* No extra bytes after the window class */
wincl.cbWndExtra = 0; /* structure or the window instance */
/* Use Windows's default color as the background of the window */
wincl.hbrBackground = (HBRUSH) COLOR_BACKGROUND;
/* Register the window class, and if it fails quit the program */
if (!RegisterClassEx (&wincl))
return 0;
/* The class is registered, let's create the program*/
hwnd = CreateWindowEx (
0, /* Extended possibilites for variation */
szClassName, /* Classname */
"Graphics", /* Title Text */
WS_OVERLAPPEDWINDOW, /* default window */
CW_USEDEFAULT, /* Windows decides the position */
CW_USEDEFAULT, /* where the window ends up on the screen */
544, /* The programs width */
375, /* and height in pixels */
HWND_DESKTOP, /* The window is a child-window to desktop */
NULL, /* No menu */
hThisInstance, /* Program Instance handler */
NULL /* No Window Creation data */
);
/* Make the window visible on the screen */
ShowWindow (hwnd, nFunsterStil);
/* Run the message loop. It will run until GetMessage() returns 0 */
while (GetMessage (&messages, NULL, 0, 0))
{
/* Translate virtual-key messages into character messages */
TranslateMessage(&messages);
/* Send message to WindowProcedure */
DispatchMessage(&messages);
}
/* The program return-value is 0 - The value that PostQuitMessage() gave */
return messages.wParam;
}
/* This function is called by the Windows function DispatchMessage() */
LRESULT CALLBACK WindowProcedure (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
algo Object(hwnd);
switch (message) /* handle the messages */
{
case WM_CREATE:
{
HMENU hMenu, hSubMenu;
hMenu = CreateMenu();
hSubMenu = CreatePopupMenu();
AppendMenu(hSubMenu, MF_STRING, ID_DDA, "DDA");
AppendMenu(hSubMenu, MF_STRING, ID_MID, "Mid-Point");
AppendMenu(hMenu, MF_STRING | MF_POPUP, (UINT_PTR)hSubMenu, "Algorithm");
hSubMenu = CreatePopupMenu();
AppendMenu(hSubMenu, MF_STRING, ID_UNDO, "Undo");
AppendMenu(hSubMenu, MF_STRING, ID_REDO, "Redo");
AppendMenu(hMenu, MF_STRING | MF_POPUP, (UINT_PTR)hSubMenu, "Edit");
SetMenu(hwnd, hMenu);
}
break;
case WM_COMMAND:
switch(LOWORD(wParam))
{
case ID_DDA:
Object.ChangeAlgo(0);
LPCSTR name;
if (Object.getAlgo() == 0)
{
name = "DDA";
}
MessageBox(hwnd, name, "Algorithm Changed", MB_OK);
break;
case ID_MID:
Object.ChangeAlgo(1);
if (Object.getAlgo() == 1)
{
name = "Mid-point";
}
MessageBox(hwnd, name, "Algorithm Changed", MB_OK);
break;
}
break;
case WM_LBUTTONDOWN :
{
int XPos = LOWORD(lParam);
int YPos = HIWORD(lParam);
if(numClicks == 0)
{
firstX = XPos ;
firstY = YPos ;
numClicks++;
}
else if(numClicks == 1)
{
lastX = XPos ;
lastY = YPos ;
numClicks = 0;
InvalidateRect(hwnd , NULL , true );
Object.Draw(firstX , firstY , lastX , lastY);
Object.setHWND(hwnd);
}
break ;
}
case WM_CLOSE:
DestroyWindow(hwnd);
break;
case WM_DESTROY:
PostQuitMessage (0); /* send a WM_QUIT to the message queue */
break;
default: /* for messages that we don't deal with */
return DefWindowProc (hwnd, message, wParam, lParam);
}
return 0;
}
现在，我正在做代码绘制线，如果我选择DDA它将用蓝色笔绘制它，如果我选择中点它将用红线绘制
并且根据变量算法，算法变量的问题发生了变化，但是线颜色没有改变，代码中的某些东西是不逻辑但我无法检测到它。
任何帮助？
答案 0 :(得分：2)
每次将消息分派到窗口过程时，您都会创建一个新的algo实例。一旦窗口过程返回，就会丢弃对响应用户事件的算法的任何更改。
还有其他各种问题：
new[]）。请尝试使用std::vector<int>代替。if (algorithm == 0)和else块看起来几乎相同。复制代码很糟糕。BeginPaint / EndPaint。这很慢并且泄漏了GDI资源。