只是一画几条线的程序，为何运行后关闭该窗口，该程序还在任务栏中的进程表里？？

Question

然怪我的电脑老卡着，

Answer 1

贴出你的onpaint或者ondraw内代码

Answer 2

#include<windows.h>LRESULT CALLBACK WndProc(HWND,UINT,WPARAM,LPARAM);
int WINAPI WinMain(
  HINSTANCE hInstance,  // handle to current instance
  HINSTANCE hPrevInstance,  // handle to previous instance
  LPSTR lpCmdLine,      // pointer to command line
  int nCmdShow          // show state of window
)
{
static TCHAR szAppName[]=TEXT("linedemo");
WNDCLASS wndclass;
HWND hwnd;
MSG msg;
wndclass.style=CS_HREDRAW|CS_VREDRAW;
wndclass.lpszMenuName=NULL;
wndclass.lpszClassName=szAppName;
wndclass.lpfnWndProc=WndProc;
wndclass.hInstance=hInstance;
wndclass.hIcon=LoadIcon(NULL,IDI_APPLICATION);
wndclass.hCursor=LoadCursor(NULL,IDC_ARROW);
wndclass.hbrBackground=(HBRUSH)GetStockObject(WHITE_BRUSH);
wndclass.cbWndExtra=0;
wndclass.cbClsExtra=0;
if(!RegisterClass(&wndclass))
{
MessageBox(NULL,TEXT("Oh,No!"),szAppName,MB_ICONERROR);
return 0;
}
hwnd=CreateWindow(szAppName,
TEXT("LINEDEMO"),
WS_OVERLAPPEDWINDOW,
CW_USEDEFAULT,
CW_USEDEFAULT,
CW_USEDEFAULT,
CW_USEDEFAULT,
NULL,
NULL,
hInstance,
NULL);
ShowWindow(hwnd,nCmdShow);
UpdateWindow(hwnd);
while(GetMessage(&msg,hwnd,0,0) )
{
TranslateMessage(&msg);
DispatchMessage(&msg);
}
return msg.wParam;
}LRESULT CALLBACK WndProc(
  HWND hwnd,      // handle to window
  UINT message,      // message identifier
  WPARAM wParam,  // first message parameter
  LPARAM lParam   // second message parameter
)
{
HDC hdc;
PAINTSTRUCT ps;
static int cxClient,cyClient;

switch(message)
{
case WM_SIZE:
cxClient=LOWORD(lParam);
cyClient=HIWORD(lParam);
return 0;
case WM_PAINT:
hdc=BeginPaint(hwnd,&ps);
MoveToEx(hdc,0,0,NULL);
LineTo(hdc,cxClient,cyClient);
MoveToEx(hdc,cxClient,0,NULL);
LineTo(hdc,0,cyClient);
Rectangle(hdc,cxClient/8,cyClient/8,7*cxClient/8,7*cyClient/8);
Ellipse(hdc,cxClient/8,cyClient/8,7*cxClient/8,7*cyClient/8);
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,      // handle to window
   message,       // message identifier
  wParam,  // first message parameter
  lParam   // second message parameter
);
}

Answer 3

还有，使用了BeginPaint需要使用EndPaint

Answer 4

我写了
EndPaint(hwnd,&ps);
啊

Answer 5

将
while(GetMessage(&msg,hwnd,0,0))
改成
while(GetMessage(&msg,NULL,0,0))

Answer 6

to happyboy086(红尘有爱) 
为何
将
while(GetMessage(&msg,hwnd,0,0))
改成
while(GetMessage(&msg,NULL,0,0))就不会出现这样的问题

Answer 7

只有WM_QUIT才能使GetMessage返回FALSE，这样while循环才能结束。
而WM_QUIT不是发送给hwnd的,你的程序永远都不能接收到WM_QUIT消息,当然驻留在内存里面了