.elseif ax==IDM_OPTION				invoke DialogBoxParam,hInstance,IDD_OPTIONDLG,hWnd,addr OptionProc,0			.elseif ax==IDM_SAVEAS				invoke RtlZeroMemory,addr ofn,sizeof ofn				mov ofn.lStructSize,sizeof ofn				push hWnd				pop ofn.hwndOwner				push hInstance				pop ofn.hInstance				mov ofn.lpstrFilter,offset ASMFilterString				mov ofn.lpstrFile,offset AlternateFileName				mov byte ptr [AlternateFileName],0				mov ofn.nMaxFile,sizeof AlternateFileName				mov ofn.Flags,OFN_FILEMUSTEXIST or OFN_HIDEREADONLY or OFN_PATHMUSTEXIST				invoke GetSaveFileName,addr ofn				.if eax!=0					invoke CreateFile,addr AlternateFileName,GENERIC_WRITE,FILE_SHARE_READ,NULL,CREATE_ALWAYS,FILE_ATTRIBUTE_NORMAL,0					.if eax!=INVALID_HANDLE_VALUE						jmp @B					.endif				.endif			.elseif ax==IDM_EXIT				invoke SendMessage,hWnd,WM_CLOSE,0,0			.endif		.endif	.elseif uMsg==WM_CLOSE		invoke CheckModifyState,hWnd		.if eax==TRUE			invoke DestroyWindow,hWnd		.endif	.elseif uMsg==WM_SIZE		mov eax,lParam		mov edx,eax		and eax,0FFFFh		shr edx,16		invoke MoveWindow,hwndRichEdit,0,0,eax,edx,TRUE			.elseif uMsg==WM_DESTROY		invoke PostQuitMessage,NULL	.else		invoke DefWindowProc,hWnd,uMsg,wParam,lParam				ret	.endif	xor eax,eax	retWndProc endpend start;===================================================================; The resource file;===================================================================#include "resource.h"#define IDR_MAINMENU                    101#define IDD_OPTIONDLG                   101#define IDC_BACKCOLORBOX                1000#define IDC_TEXTCOLORBOX                1001#define IDM_OPEN                        40001#define IDM_SAVE                        40002#define IDM_CLOSE                       40003#define IDM_SAVEAS                      40004#define IDM_EXIT                        40005#define IDM_COPY                        40006#define IDM_CUT                         40007#define IDM_PASTE                       40008#define IDM_DELETE                      40009#define IDM_SELECTALL                   40010#define IDM_OPTION                      40011#define IDM_UNDO                        40012#define IDM_REDO                        40013IDR_MAINMENU MENU DISCARDABLE BEGIN    POPUP "&File"    BEGIN        MENUITEM "&Open",                       IDM_OPEN        MENUITEM "&Close",                      IDM_CLOSE        MENUITEM "&Save",                       IDM_SAVE        MENUITEM "Save &As",                    IDM_SAVEAS        MENUITEM SEPARATOR        MENUITEM "E&xit",                       IDM_EXIT    END    POPUP "&Edit"    BEGIN        MENUITEM "&Undo",                       IDM_UNDO        MENUITEM "&Redo",                       IDM_REDO        MENUITEM "&Copy",                       IDM_COPY        MENUITEM "C&ut",                        IDM_CUT        MENUITEM "&Paste",                      IDM_PASTE        MENUITEM SEPARATOR        MENUITEM "&Delete",                     IDM_DELETE        MENUITEM SEPARATOR        MENUITEM "Select &All",                 IDM_SELECTALL    END    MENUITEM "Options",                     IDM_OPTIONENDIDD_OPTIONDLG DIALOG DISCARDABLE  0, 0, 183, 54STYLE DS_MODALFRAME | WS_POPUP | WS_VISIBLE | WS_CAPTION | WS_SYSMENU | DS_CENTERCAPTION "Options"FONT 8, "MS Sans Serif"BEGIN    DEFPUSHBUTTON   "OK",IDOK,137,7,39,14    PUSHBUTTON      "Cancel",IDCANCEL,137,25,39,14    GROUPBOX        "",IDC_STATIC,5,0,124,49    LTEXT           "Background Color:",IDC_STATIC,20,14,60,8    LTEXT           "",IDC_BACKCOLORBOX,85,11,28,14,SS_NOTIFY | WS_BORDER    LTEXT           "Text Color:",IDC_STATIC,20,33,35,8    LTEXT           "",IDC_TEXTCOLORBOX,85,29,28,14,SS_NOTIFY | WS_BORDEREND</font></b></pre><hr noshade><h3 align="left"><font face="Times New Roman, Times, serif" color="#0000CC">Analysis:</font></h3><p align="left"><font face="Tahoma" size="-1">The program first loads the richedit   dll, which in this case is riched20.dll. If the dll cannot be loaded, it exits   to Windows.</font><br></p><pre align="left"><b><font face="Tahoma"><font color="#FF0033">invoke LoadLibrary,addr RichEditDLL</font> .if eax!=0 	mov hRichEdit,eax 	invoke WinMain,hInstance,0,0, SW_SHOWDEFAULT 	invoke FreeLibrary,hRichEdit .else 	invoke MessageBox,0,addr NoRichEdit,addr AppName,MB_OK or MB_ICONERROR .endif invoke ExitProcess,eax</font></b></pre><p align="left"><font face="Tahoma" size="-1">After the dll is loaded successfully,   we proceed to create a normal window which will be the parent of the richedit   control. Within the <font color="#006666"><b>WM_CREATE</b></font> handler, we   create the richedit control:</font></p><pre align="left"><b><font face="Tahoma">		invoke CreateWindowEx,WS_EX_CLIENTEDGE,addr RichEditClass,0,WS_CHILD or WS_VISIBLE or ES_MULTILINE or WS_VSCROLL or WS_HSCROLL or ES_NOHIDESEL,\				CW_USEDEFAULT,CW_USEDEFAULT, CW_USEDEFAULT, CW_USEDEFAULT,hWnd,RichEditID,hInstance,0		mov hwndRichEdit,eax</font></b></pre><p align="left"><font face="Tahoma" size="-1">Note that we specify<font color="#006666"><b>   ES_MULTILINE</b></font> style else the control will be a single-lined one.</font><b><font face="Tahoma" size="-1">   <br>  </font></b></p><pre align="left"><b><font face="Tahoma">		invoke SendMessage,hwndRichEdit,EM_LIMITTEXT,-1,0</font></b></pre><p align="left"><font face="Tahoma" size="-1">After the richedit control is created,   we must set the new text limit on it. By default, the richedit control has 64K   text limit, the same as a simple multi-line edit control. We must extend this   limit to allow it to operate with larger files. In the above line, I specify   -1 which amounts to 0FFFFFFFFh, a very large value.</font></p><pre align="left"><font face="Tahoma">     </font><b><font face="Tahoma"> </font></b><b><font face="Tahoma"> invoke SetColor</font></b></pre><p align="left"><b><font face="Tahoma"><br>  </font></b><font face="Tahoma" size="-1">Next, we set the text/background </font><font face="Tahoma" size="-1">color.   Since this operation can be performed in other part of the program, I put the   code in a function named SetColor.</font><b><font face="Tahoma" size="-1"> <br>  </font></b></p><pre align="left"><b><font face="Tahoma"><font color="#003399">SetColor</font> proc	LOCAL cfm:CHARFORMAT	invoke SendMessage,hwndRichEdit,EM_SETBKGNDCOLOR,0,BackgroundColor</font></b></pre><p align="left"><font face="Tahoma" size="-1">Setting the background color of   the richedit control is a straightforward operation: just send <font color="#006666"><b>EM_SETBKGNDCOLOR</b></font>   message to the richedit control. (If you use a multi-line edit control, you   have to process <font color="#006666"><b>WM_CTLCOLOREDIT</b></font>). The default   background color is white. </font><b><font face="Tahoma" size="-1"> <br>  </font></b></p><pre align="left"><b><font face="Tahoma">	invoke RtlZeroMemory,addr cfm,sizeof cfm	mov cfm.cbSize,sizeof cfm	mov cfm.dwMask,CFM_COLOR	push TextColor	pop cfm.crTextColor</font></b></pre><p align="left"><font face="Tahoma" size="-1">After the background color is set,   we fill in the members of <font color="#006666"><b>CHARFORMAT</b></font> in   order to set the text color. Note that we fill <font color="#006666"><b>cbSize</b></font>   with the size of the structure so the richedit control knows we are sending   it <font color="#006666"><b>CHARFORMAT</b></font>, not <font color="#006666"><b>CHARFORMAT2</b></font>.   <font color="#006666"> <b>dwMask</b></font> has only one flag, <font color="#0000CC"><b>CFM_COLOR</b></font>,   because we only want to set the text color and <font color="#006666"><b>crTextColor</b></font>   is filled with the value of the desired text color. </font></p><pre align="left"><b><font face="Tahoma">	invoke SendMessage,hwndRichEdit,EM_SETCHARFORMAT,SCF_ALL,addr cfm	ret<font color="#003399">SetColor</font> endp</font></b></pre><p align="left"><font face="Tahoma" size="-1">After settting the color, you have   to empty undo buffer simply because the act of changing text/background color   is undo-able. We send <font color="#006666"><b>EM_EMPTYUNDOBUFFER</b></font>   message to achieve this.</font></p><pre align="left"><font face="Tahoma" size="-1"><b>	invoke SendMessage,hwndRichEdit,EM_EMPTYUNDOBUFFER,0,0</b></font><b><font face="Tahoma"> </font></b></pre><p align="left"><font face="Tahoma" size="-1">After filling the <font color="#006666"><b>CHARFORMAT</b></font>   structure, we send <font color="#006666"><b>EM_SETCHARFORMAT</b></font> to the   richedit control, specifying <font color="#0000CC"><b>SCF_ALL</b></font> flag   in <font color="#CC0033"><b>wParam</b></font> to indicate that we want the text   formatting to be applied to all text in the control.</font><b><font face="Tahoma" size="-1">   </font></b></p><p><font face="Tahoma" size="-1">Note that when we first created the richedit   control, we didn't specify its size/position at that time. That's because we   want it to cover the whole client area of the parent window. We resize it whenever   the size of the parent window changes.</font></p><pre><b><font face="Tahoma">	.elseif uMsg==WM_SIZE		mov eax,lParam		mov edx,eax		and eax,0FFFFh		shr edx,16		invoke MoveWindow,hwndRichEdit,0,0,eax,edx,TRUE</font></b></pre><p><font face="Tahoma" size="-1">In the above code snippet, we use the new dimension   of the client area passed in <font color="#0000CC"><b>lParam</b></font> to resize   the richedit control with <font color="#009999"><b><font color="#006666">MoveWindow</font></b></font>.</font></p><p><font face="Tahoma" size="-1">When the user clicks on the File/Edit menu bar,   we process <font color="#006666"><b>WM_INITPOPUPMENU</b></font> so that we can   prepare the states of the menuitems in the submenu before displaying it to the   user. For example, if a file is already opened in the richedit control, we want   to disable the open menuitem and enable all the remaining menuitems.</font></p><p><font face="Tahoma" size="-1">In the case of the File menu bar, we use the   variable <font color="#0000CC"><b>FileOpened</b></font> as the flag to determine   whether a file is already opened. If the value in this variable is TRUE, we   know that a file is already opened.</font></p><pre><b><font face="Tahoma">	.elseif uMsg==WM_INITMENUPOPUP		mov eax,lParam		.if ax==0		; file menu						.if FileOpened==TRUE	; a file is already opened				invoke EnableMenuItem,wParam,IDM_OPEN,MF_GRAYED				invoke EnableMenuItem,wParam,IDM_CLOSE,MF_ENABLED				invoke EnableMenuItem,wParam,IDM_SAVE,MF_ENABLED				invoke EnableMenuItem,wParam,IDM_SAVEAS,MF_ENABLED			.else				invoke EnableMenuItem,wParam,IDM_OPEN,MF_ENABLED				invoke EnableMenuItem,wParam,IDM_CLOSE,MF_GRAYED				invoke EnableMenuItem,wParam,IDM_SAVE,MF_GRAYED				invoke EnableMenuItem,wParam,IDM_SAVEAS,MF_GRAYED			.endif</font></b></pre><p><font face="Tahoma" size="-1">As you can see, if a file is already opened,   we gray out the open menuitem and enable the remaining menuitems. The reverse   is true of <font color="#0000CC"><b>FileOpened</b></font> is false.</font></p><p><font face="Tahoma" size="-1">In the case of the edit menu bar, we need to   check the state of the richedit control/clipboard first.</font></p><pre><b><font face="Tahoma">			invoke SendMessage,hwndRichEdit,EM_CANPASTE,CF_TEXT,0			.if eax==0		; no text in the clipboard				invoke EnableMenuItem,wParam,IDM_PASTE,MF_GRAYED			.else				invoke EnableMenuItem,wParam,IDM_PASTE,MF_ENABLED			.endif</font></b></pre><p><font face="Tahoma" size="-1">We first check whether some text is available   in the clipboard by sending <font color="#006666"><b>EM_CANPASTE</b></font>   message. If some text is available, <font color="#0000CC"><b>SendMessage</b></font>   returns TRUE and we enable the paste menuitem. If not, we gray out the menuitem.   </font></p><pre><b><font face="Tahoma">			invoke SendMessage,hwndRichEdit,EM_CANUNDO,0,0			.if eax==0				invoke EnableMenuItem,wParam,IDM_UNDO,MF_GRAYED			.else				invoke EnableMenuItem,wParam,IDM_UNDO,MF_ENABLED			.endif</font></b></pre><p><font face="Tahoma" size="-1">Next, we check whether the undo buffer is empty   by sending <font color="#006666"><b>EM_CANUNDO</b></font> message. If it's not   empty, <font color="#0000CC"><b>SendMessage</b></font> returns TRUE and we enable   the undo menuitem. </font></p><pre><b><font face="Tahoma">			invoke SendMessage,hwndRichEdit,EM_CANREDO,0,0			.if eax==0				invoke EnableMenuItem,wParam,IDM_REDO,MF_GRAYED			.else				invoke EnableMenuItem,wParam,IDM_REDO,MF_ENABLED			.endif</font></b></pre><p><font face="Tahoma" size="-1">We check the redo buffer by sending <font color="#006666"><b>EM_CANREDO</b></font>   message to the richedit control. If it's not empty, <font color="#0000CC"><b>SendMessage</b></font>   returns TRUE and we enable the redo menuitem. </font><b><font face="Tahoma" size="-1">   </font></b></p><pre><b><font face="Tahoma">			invoke SendMessage,hwndRichEdit,EM_EXGETSEL,0,addr chrg			mov eax,chrg.cpMin			.if eax==chrg.cpMax		; no current selection				invoke EnableMenuItem,wParam,IDM_COPY,MF_GRAYED				invoke EnableMenuItem,wParam,IDM_CUT,MF_GRAYED				invoke EnableMenuItem,wParam,IDM_DELETE,MF_GRAYED			.else				invoke EnableMenuItem,wParam,IDM_COPY,MF_ENABLED				invoke EnableMenuItem,wParam,IDM_CUT,MF_ENABLED				invoke EnableMenuItem,wParam,IDM_DELETE,MF_ENABLED			.endif</font></b></pre><p><font face="Tahoma" size="-1">Lastly, we check whether a current selection   exists by sending <font color="#006666"><b>EM_EX