《Windows程式設計》之列表框控制項

這部分代碼是書中HEAD的部分，裡面的東西值得細細去理會

LRESULT CALLBACK WndProc(HWND hwnd,UINT message,WPARAM wParam,LPARAM lParam){static BOOL bValidFile;static BYTE buffer[MAXREAD];static HWND hwndList,hwndText;static RECT rect;static TCHAR szFile[MAX_PATH+1];HANDLE hFile;HDC hdc;int i,cxChar,cyChar;PAINTSTRUCT ps;TCHAR szBuffer[MAX_PATH+1];switch(message){case WM_CREATE://系統字型中字元的寬高cxChar=LOWORD(GetDialogBaseUnits());cyChar=HIWORD(GetDialogBaseUnits());//矩形左上方座標rect.left=20*cxChar;rect.top=3*cyChar;//建立列表框控制項，並設定位置，大小hwndList=CreateWindow(TEXT("listbox"),NULL,WS_CHILDWINDOW|WS_VISIBLE|LBS_STANDARD,cxChar,cyChar*3,cxChar*13+GetSystemMetrics(SM_CXVSCROLL),cyChar*10,hwnd,(HMENU)ID_LIST,(HINSTANCE)GetWindowLong(hwnd,GWL_HINSTANCE),NULL);//擷取當前路徑GetCurrentDirectory(MAX_PATH+1,szBuffer);//建立文字框控制項，並設定位置，大小hwndText=CreateWindow(TEXT("static"),szBuffer,WS_CHILDWINDOW|WS_VISIBLE|SS_LEFT,cxChar,cyChar,cxChar*MAX_PATH,cyChar,hwnd,(HMENU)ID_TEXT,(HINSTANCE)GetWindowLong(hwnd,GWL_HINSTANCE),NULL);//回調OldList=(WNDPROC)SetWindowLong(hwndList,GWL_WNDPROC,(LPARAM)ListProc);//List Box最強大的一條訊息：LB_DIR//DIRATTR是檔案屬性，"*.*"是檔案匹配名SendMessage(hwndList,LB_DIR,DIRATTR,(LPARAM)TEXT("*.*"));return 0;case WM_SIZE:rect.right=LOWORD(lParam);rect.bottom=HIWORD(lParam);return 0;case WM_SETFOCUS:SetFocus(hwndList);return 0;case WM_COMMAND:if(LOWORD(wParam)==ID_LIST&&HIWORD(wParam)==LBN_DBLCLK){//擷取雙擊的是哪個if(LB_ERR==(i=SendMessage(hwndList,LB_GETCURSEL,0,0)))break;//擷取文本SendMessage(hwndList,LB_GETTEXT,i,(LPARAM)szBuffer);if(INVALID_HANDLE_VALUE!=(hFile=CreateFile(szBuffer,GENERIC_READ,FILE_SHARE_READ,NULL,OPEN_EXISTING,0,NULL))){//為檔案CloseHandle(hFile);bValidFile=TRUE;lstrcpy(szFile,szBuffer);GetCurrentDirectory(MAX_PATH+1,szBuffer);if(szBuffer[lstrlen(szBuffer)-1]!='\\')lstrcat(szBuffer,TEXT("\\"));SetWindowText(hwndText,lstrcat(szBuffer,szFile));}else{//為檔案夾bValidFile=FALSE;szBuffer[lstrlen(szBuffer)-1]='\0';if(!SetCurrentDirectory(szBuffer+1)){szBuffer[3]=':';szBuffer[4]='\0';SetCurrentDirectory(szBuffer+2);}GetCurrentDirectory(MAX_PATH+1,szBuffer);SetWindowText(hwndText,szBuffer);SendMessage(hwndList,LB_RESETCONTENT,0,0);SendMessage(hwndList,LB_DIR,DIRATTR,(LPARAM)TEXT("*.*"));}//觸發WM_PAINTInvalidateRect(hwnd,NULL,TRUE);}return 0;case WM_PAINT:if(!bValidFile)break;if(INVALID_HANDLE_VALUE==(hFile=CreateFile(szFile,GENERIC_READ,FILE_SHARE_READ,NULL,OPEN_EXISTING,0,NULL))){bValidFile=FALSE;break;}//讀取檔案內容ReadFile(hFile,buffer,MAXREAD,(LPDWORD)&i,NULL);CloseHandle(hFile);hdc=BeginPaint(hwnd,&ps);SelectObject(hdc,GetStockObject(SYSTEM_FIXED_FONT));SetTextColor(hdc,GetSysColor(COLOR_BTNTEXT));SetBkColor(hdc,GetSysColor(COLOR_BTNFACE));//列印到視窗DrawTextA(hdc,(LPCSTR)buffer,i,&rect,DTFLAGS);EndPaint(hwnd,&ps);return 0;case WM_DESTROY:PostQuitMessage(0);return 0;}return DefWindowProc(hwnd,message,wParam,lParam);}