主题:[讨论]mfc api函数 ScrollWindow的问题
BTNLOOK.C
/*--------------------------------------------------------------------------
BTNLOOK.C -- Button Look Program
(c) Charles Petzold, 1998
---------------------------------------------------------------------------*/
#include <windows.h>
struct
{
int iStyle ;
TCHAR * szText ;
}
button[] =
{
BS_PUSHBUTTON, TEXT ("PUSHBUTTON"),
BS_DEFPUSHBUTTON, TEXT ("DEFPUSHBUTTON"),
BS_CHECKBOX, TEXT ("CHECKBOX"),
BS_AUTOCHECKBOX, TEXT ("AUTOCHECKBOX"),
BS_RADIOBUTTON, TEXT ("RADIOBUTTON"),
BS_3STATE, TEXT ("3STATE"),
BS_AUTO3STATE, TEXT ("AUTO3STATE"),
BS_GROUPBOX, TEXT ("GROUPBOX"),
BS_AUTORADIOBUTTON, TEXT ("AUTORADIO"),
BS_OWNERDRAW, TEXT ("OWNERDRAW")
} ;
#define NUM (sizeof button / sizeof button[0])
LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM) ;
int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
PSTR szCmdLine, int iCmdShow)
{
static TCHAR szAppName[] = TEXT ("BtnLook") ;
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 ("This program requires Windows NT!"),
szAppName, MB_ICONERROR) ;
return 0 ;
}
hwnd = CreateWindow (szAppName, TEXT ("Button Look"),
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)
{
static HWND hwndButton[NUM] ;
static RECT rect ;
static TCHAR szTop[] = TEXT ("message wParam lParam"),
szUnd[] = TEXT ("_______ ______ ______"),
szFormat[] = TEXT ("%-16s%04X-%04X %04X-%04X"),
szBuffer[50] ;
static int cxChar, cyChar ;
HDC hdc ;
PAINTSTRUCT ps ;
int i ;
switch (message)
{
case WM_CREATE :
cxChar = LOWORD (GetDialogBaseUnits ()) ;
cyChar = HIWORD (GetDialogBaseUnits ()) ;
for (i = 0 ; i < NUM ; i++)
hwndButton[i] =CreateWindow ( TEXT("button"),button[i].szText,
WS_CHILD | WS_VISIBLE | button[i].iStyle,
cxChar, cyChar * (1 + 2 * i),
20 * cxChar, 7 * cyChar / 4,
hwnd, (HMENU) i,
((LPCREATESTRUCT) lParam)->hInstance, NULL) ;
return 0 ;
case WM_SIZE :
rect.left = 24 * cxChar ;
rect.top = 2 * cyChar ;
rect.right = LOWORD (lParam) ;
rect.bottom = HIWORD (lParam) ;
return 0 ;
case WM_PAINT :
InvalidateRect (hwnd, &rect, TRUE) ;
hdc = BeginPaint (hwnd, &ps) ;
SelectObject (hdc, GetStockObject (SYSTEM_FIXED_FONT)) ;
SetBkMode (hdc, TRANSPARENT) ;
TextOut (hdc, 24 * cxChar, cyChar, szTop, lstrlen (szTop)) ;
TextOut (hdc, 24 * cxChar, cyChar, szUnd, lstrlen (szUnd)) ;
EndPaint (hwnd, &ps) ;
return 0 ;
case WM_DRAWITEM :
case WM_COMMAND :
ScrollWindow (hwnd, 0, -cyChar, &rect, &rect) ;
hdc = GetDC (hwnd) ;
SelectObject (hdc, GetStockObject (SYSTEM_FIXED_FONT)) ;
TextOut( hdc, 24 * cxChar, cyChar * (rect.bottom / cyChar - 1),
szBuffer,
wsprintf (szBuffer, szFormat,
message == WM_DRAWITEM ? TEXT ("WM_DRAWITEM") :
TEXT ("WM_COMMAND"),
HIWORD (wParam), LOWORD (wParam),
HIWORD (lParam), LOWORD (lParam))) ;
ReleaseDC (hwnd, hdc) ;
ValidateRect (hwnd, &rect) ;
break ;
case WM_DESTROY :
PostQuitMessage (0) ;
return 0 ;
}
return DefWindowProc (hwnd, message, wParam, lParam) ;
}
___________________________________________________
这段代码里面ScrollWindow (hwnd, 0, -cyChar, &rect, &rect) 是怎么工作的啊
他不是结束后产生WM_PAINT消息?
那怎么不是会使开始输出的内容刷新了吗, 运行的时候怎么不是这样的,
那位高手能解释一下,ScrollWindow (hwnd, 0, -cyChar, &rect, &rect) 是怎么工作的?
/*--------------------------------------------------------------------------
BTNLOOK.C -- Button Look Program
(c) Charles Petzold, 1998
---------------------------------------------------------------------------*/
#include <windows.h>
struct
{
int iStyle ;
TCHAR * szText ;
}
button[] =
{
BS_PUSHBUTTON, TEXT ("PUSHBUTTON"),
BS_DEFPUSHBUTTON, TEXT ("DEFPUSHBUTTON"),
BS_CHECKBOX, TEXT ("CHECKBOX"),
BS_AUTOCHECKBOX, TEXT ("AUTOCHECKBOX"),
BS_RADIOBUTTON, TEXT ("RADIOBUTTON"),
BS_3STATE, TEXT ("3STATE"),
BS_AUTO3STATE, TEXT ("AUTO3STATE"),
BS_GROUPBOX, TEXT ("GROUPBOX"),
BS_AUTORADIOBUTTON, TEXT ("AUTORADIO"),
BS_OWNERDRAW, TEXT ("OWNERDRAW")
} ;
#define NUM (sizeof button / sizeof button[0])
LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM) ;
int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
PSTR szCmdLine, int iCmdShow)
{
static TCHAR szAppName[] = TEXT ("BtnLook") ;
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 ("This program requires Windows NT!"),
szAppName, MB_ICONERROR) ;
return 0 ;
}
hwnd = CreateWindow (szAppName, TEXT ("Button Look"),
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)
{
static HWND hwndButton[NUM] ;
static RECT rect ;
static TCHAR szTop[] = TEXT ("message wParam lParam"),
szUnd[] = TEXT ("_______ ______ ______"),
szFormat[] = TEXT ("%-16s%04X-%04X %04X-%04X"),
szBuffer[50] ;
static int cxChar, cyChar ;
HDC hdc ;
PAINTSTRUCT ps ;
int i ;
switch (message)
{
case WM_CREATE :
cxChar = LOWORD (GetDialogBaseUnits ()) ;
cyChar = HIWORD (GetDialogBaseUnits ()) ;
for (i = 0 ; i < NUM ; i++)
hwndButton[i] =CreateWindow ( TEXT("button"),button[i].szText,
WS_CHILD | WS_VISIBLE | button[i].iStyle,
cxChar, cyChar * (1 + 2 * i),
20 * cxChar, 7 * cyChar / 4,
hwnd, (HMENU) i,
((LPCREATESTRUCT) lParam)->hInstance, NULL) ;
return 0 ;
case WM_SIZE :
rect.left = 24 * cxChar ;
rect.top = 2 * cyChar ;
rect.right = LOWORD (lParam) ;
rect.bottom = HIWORD (lParam) ;
return 0 ;
case WM_PAINT :
InvalidateRect (hwnd, &rect, TRUE) ;
hdc = BeginPaint (hwnd, &ps) ;
SelectObject (hdc, GetStockObject (SYSTEM_FIXED_FONT)) ;
SetBkMode (hdc, TRANSPARENT) ;
TextOut (hdc, 24 * cxChar, cyChar, szTop, lstrlen (szTop)) ;
TextOut (hdc, 24 * cxChar, cyChar, szUnd, lstrlen (szUnd)) ;
EndPaint (hwnd, &ps) ;
return 0 ;
case WM_DRAWITEM :
case WM_COMMAND :
ScrollWindow (hwnd, 0, -cyChar, &rect, &rect) ;
hdc = GetDC (hwnd) ;
SelectObject (hdc, GetStockObject (SYSTEM_FIXED_FONT)) ;
TextOut( hdc, 24 * cxChar, cyChar * (rect.bottom / cyChar - 1),
szBuffer,
wsprintf (szBuffer, szFormat,
message == WM_DRAWITEM ? TEXT ("WM_DRAWITEM") :
TEXT ("WM_COMMAND"),
HIWORD (wParam), LOWORD (wParam),
HIWORD (lParam), LOWORD (lParam))) ;
ReleaseDC (hwnd, hdc) ;
ValidateRect (hwnd, &rect) ;
break ;
case WM_DESTROY :
PostQuitMessage (0) ;
return 0 ;
}
return DefWindowProc (hwnd, message, wParam, lParam) ;
}
___________________________________________________
这段代码里面ScrollWindow (hwnd, 0, -cyChar, &rect, &rect) 是怎么工作的啊
他不是结束后产生WM_PAINT消息?
那怎么不是会使开始输出的内容刷新了吗, 运行的时候怎么不是这样的,
那位高手能解释一下,ScrollWindow (hwnd, 0, -cyChar, &rect, &rect) 是怎么工作的?