Question

API 编程 对话框问题 求大牛解答

API编程时 调用对话框和消息盒时 有时显示出来，有时就显示不出来，显示不出来后，我就来回切换其他应用程序和我编出来的程序，切换几次就好了，以前编的东西都没有这种问题，求大牛。

Answer 1

这是我抄书上的一个程序，但是不能够正确允许，点击菜单的时候，对话框不能显示出来。程序如下，请大家给看看，谢谢！
资源文件：
//Microsoft Developer Studio generated resource script.
//
#include "resource.h "

#define APSTUDIO_READONLY_SYMBOLS
/////////////////////////////////////////////////////////////////////////////
//
// Generated from the TEXTINCLUDE 2 resource.
//
#include "afxres.h "

/////////////////////////////////////////////////////////////////////////////
#undef APSTUDIO_READONLY_SYMBOLS

/////////////////////////////////////////////////////////////////////////////
// Chinese (P.R.C.) resources

#if !defined(AFX_RESOURCE_DLL) || defined(AFX_TARG_CHS)
#ifdef _WIN32
LANGUAGE LANG_CHINESE, SUBLANG_CHINESE_SIMPLIFIED
#pragma code_page(936)
#endif //_WIN32

/////////////////////////////////////////////////////////////////////////////
//
// Menu
//

ABOUT1 MENU DISCARDABLE
BEGIN
POPUP "帮助 "
BEGIN
MENUITEM "帮助主题 ", IDM_HELP
MENUITEM "关于 ", IDM_ABOUT
END
END

#ifdef APSTUDIO_INVOKED
/////////////////////////////////////////////////////////////////////////////
//
// TEXTINCLUDE
//

1 TEXTINCLUDE DISCARDABLE
BEGIN
"resource.h\0 "
END

2 TEXTINCLUDE DISCARDABLE
BEGIN
"#include " "afxres.h " "\r\n "
"\0 "
END

3 TEXTINCLUDE DISCARDABLE
BEGIN
"\r\n "
"\0 "
END

#endif // APSTUDIO_INVOKED

/////////////////////////////////////////////////////////////////////////////
//
// Dialog
//

ABOUTBOX DIALOG DISCARDABLE 0, 0, 187, 94
STYLE DS_MODALFRAME | WS_POPUP | WS_CAPTION | WS_SYSMENU
CAPTION "Dialog "
FONT 10, "System "
BEGIN
DEFPUSHBUTTON "OK ",IDOK,130,7,50,14
PUSHBUTTON "Cancel ",IDCANCEL,130,24,50,14
LTEXT "关于 ",IDC_STATIC,38,29,63,26
COMBOBOX IDC_COMBO1,94,47,48,30,CBS_DROPDOWN | CBS_SORT |
WS_VSCROLL | WS_TABSTOP
END

HELP DIALOG DISCARDABLE 0, 0, 187, 94
STYLE DS_MODALFRAME | WS_POPUP | WS_VISIBLE | WS_CAPTION | WS_SYSMENU
CAPTION "Dialog "
FONT 10, "System "
BEGIN
DEFPUSHBUTTON "OK ",IDOK,130,7,50,14
PUSHBUTTON "Cancel ",IDCANCEL,130,24,50,14
LTEXT "帮助 ",IDC_STATIC,49,29,39,36
END

IDD_DIALOG1 DIALOG DISCARDABLE 0, 0, 187, 94
STYLE DS_MODALFRAME | WS_POPUP | WS_CAPTION | WS_SYSMENU
CAPTION "Dialog "
FONT 10, "System "
BEGIN
DEFPUSHBUTTON "OK ",IDOK,130,7,50,14
PUSHBUTTON "Cancel ",IDCANCEL,130,24,50,14
END

/////////////////////////////////////////////////////////////////////////////
//
// DESIGNINFO
//

#ifdef APSTUDIO_INVOKED
GUIDELINES DESIGNINFO DISCARDABLE
BEGIN
ABOUTBOX, DIALOG
BEGIN
LEFTMARGIN, 7
RIGHTMARGIN, 180
TOPMARGIN, 7
BOTTOMMARGIN, 87
END

HELP, DIALOG
BEGIN
LEFTMARGIN, 7
RIGHTMARGIN, 180
TOPMARGIN, 7
BOTTOMMARGIN, 87
END

IDD_DIALOG1, DIALOG
BEGIN
LEFTMARGIN, 7
RIGHTMARGIN, 180
TOPMARGIN, 7
BOTTOMMARGIN, 87
END
END
#endif // APSTUDIO_INVOKED

#endif // Chinese (P.R.C.) resources
/////////////////////////////////////////////////////////////////////////////

#ifndef APSTUDIO_INVOKED
/////////////////////////////////////////////////////////////////////////////
//
// Generated from the TEXTINCLUDE 3 resource.
//

/////////////////////////////////////////////////////////////////////////////
#endif // not APSTUDIO_INVOKED

自动生成的头文件resource.h：
//{{NO_DEPENDENCIES}}
// Microsoft Developer Studio generated include file.
// Used by Script1.rc
//
#define ABOUT1 101
#define ABOUTBOX 102
#define HELP 103
#define IDD_DIALOG1 104
#define IDC_COMBO1 1000
#define IDM_HELP 40001
#define IDM_ABOUT 40002

// Next default values for new objects
//
#ifdef APSTUDIO_INVOKED
#ifndef APSTUDIO_READONLY_SYMBOLS
#define _APS_NEXT_RESOURCE_VALUE 105
#define _APS_NEXT_COMMAND_VALUE 40003
#define _APS_NEXT_CONTROL_VALUE 1001
#define _APS_NEXT_SYMED_VALUE 101
#endif
#endif

程序文件：
#include <windows.h>

#include "resource.h "

HWND hWndModeless=NULL;

LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);

//对话框窗口处理函数

BOOL CALLBACK AboutDlgProc(HWND, UINT, WPARAM, LPARAM);

BOOL CALLBACK HelpDlgProc(HWND, UINT, WPARAM, LPARAM);
int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,

PSTR szCmdLine, int iCmdShow)

{

static char szAppName[] = "About1 " ;

MSG msg ;

HWND hwnd ;

WNDCLASSEX wndclass ;
HMENU hMenu;
hMenu=LoadMenu(hInstance,MAKEINTRESOURCE(ABOUT1));

wndclass.cbSize = sizeof (wndclass) ;

wndclass.style = CS_HREDRAW | CS_VREDRAW ;

wndclass.lpfnWndProc = WndProc ;

wndclass.cbClsExtra = 0 ;

wndclass.cbWndExtra = 0 ;

wndclass.hInstance = hInstance ;

wndclass.hIcon = LoadIcon (hInstance, szAppName) ;

wndclass.hCursor = LoadCursor (NULL, IDC_ARROW) ;

wndclass.hbrBackground = (HBRUSH) GetStockObject (WHITE_BRUSH) ;

wndclass.lpszMenuName = szAppName ;

wndclass.lpszClassName = szAppName ;

wndclass.hIconSm = LoadIcon (hInstance, szAppName) ;

RegisterClassEx (&wndclass) ;

hwnd = CreateWindow (szAppName, "对话框示例 ",

WS_OVERLAPPEDWINDOW,

CW_USEDEFAULT, CW_USEDEFAULT,

CW_USEDEFAULT, CW_USEDEFAULT,

NULL,hMenu, hInstance, NULL) ;

ShowWindow (hwnd, iCmdShow) ;

UpdateWindow (hwnd) ;

while (GetMessage (&msg, NULL, 0, 0))

{//截获非模态对话框消息并发往处理函数

if(!IsDialogMessage(hWndModeless,&msg))

{

TranslateMessage (&msg) ;

DispatchMessage (&msg) ;

}

}

return msg.wParam ;

}
LRESULT CALLBACK WndProc (HWND hwnd, UINT iMsg, WPARAM wParam, LPARAM lParam)

{

static WNDPROC lpfnAboutDlgProc ;

static HINSTANCE hInstance ;

switch (iMsg)

{

case WM_CREATE :

hInstance = ((LPCREATESTRUCT) lParam)-> hInstance ;

return 0 ;

case WM_COMMAND :

switch (LOWORD (wParam))

{

case IDM_ABOUT :

//调用DialogBox函数显示模态对话框

DialogBox (hInstance, "ABOUTBOX ", hwnd, AboutDlgProc) ;

return 0 ;

case IDM_HELP:

//调用CreateDialog函数显示非模态对话框

hWndModeless=CreateDialog(hInstance, "HELP ", hwnd, HelpDlgProc);

ShowWindow(hWndModeless,SW_SHOW);

}

break ;

case WM_DESTROY :

PostQuitMessage (0) ;

return 0 ;

}

return DefWindowProc (hwnd, iMsg, wParam, lParam) ;

}
BOOL CALLBACK AboutDlgProc (HWND hDlg, UINT iMsg, WPARAM wParam, LPARAM lParam)

{

switch (iMsg)

{

case WM_INITDIALOG :

return TRUE ;
case WM_COMMAND :

switch (LOWORD (wParam))

{

case IDOK :

case IDCANCEL :

EndDialog (hDlg, 0) ; //关闭模态对话框

return TRUE ;

}

break ;

}

return FALSE ;

}
BOOL CALLBACK HelpDlgProc (HWND hDlg, UINT iMsg, WPARAM wParam, LPARAM lParam)

{

switch (iMsg)

{

case WM_INITDIALOG :

return TRUE ;
case WM_COMMAND :

switch (LOWORD (wParam))

{

case IDOK :

case IDCANCEL :

DestroyWindow(hDlg) ; //关闭非模态对话框

return TRUE ;

}

break ;

}

return FALSE ;

Answer 2

设置对话框和消息框的父窗口。