Non-modal dialog box in Windows Programming

# Include <windows. h> lresult callback wndproc (hwnd, uint, wparam, lparam); bool callback colorscrdlg (hwnd, uint, wparam, lparam); hwnd hdlgmodeless; int winapi winmain (hinstance, hinstance hprevinstance, pstr szcmdline, int icmdshow) {static tchar szappname [] = text ("color2"); MSG; hwnd; wndclass. style = cs_vredraw | cs_hredraw; wndclass. lpfnwndproc = wndproc; wndclass. cbclsextra = 0; wndcia SS. cbwndextra = 0; wndclass. hbrbackground = createsolidbrush (0l); wndclass. hinstance = hinstance; wndclass. hicon = loadicon (null, idi_application); wndclass. hcursor = loadcursor (null, idc_arrow); wndclass. lpszmenuname = NULL; wndclass. lpszclassname = szappname; If (! Registerclass (& wndclass) {MessageBox (null, text ("this program requires Windows NT! "), Szappname, mb_iconerror); Return 0;} // ws_clipchildren indicates that the repaster window hwnd = createwindow (szappname, text (" color scroll ") does not erase the dialog box "), required | ws_clipchildren, cw_usedefault, null, null, hinstance, null); showwindow (hwnd, icmdshow); updatewindow (hwnd); hdlgmodeless = createdi( alog hinstance, text ("colorscrdlg"), hwnd, colorscrdlg); While (getmessage (& MSG, null,) {// determine this location Whether the message breaking cycle is the IF (hdlgmodeless = 0 |! Isdialogmessage (hdlgmodeless, & MSG) {translatemessage (& MSG); dispatchmessage (& MSG) ;}} return MSG. wparam;} lresult callback wndproc (hwnd, uint message, wparam, lparam) {Switch (Message) {Case wm_destroy: // change the background brush of the class before closing, and delete the newly created deleteobject (hgdiobj) setclasslong (hwnd, gcl_hbrbackground, (long) getstockobject (white_brush ))); postquitmessage (0); Return 0;} return defwindowproc (hwnd, message, wparam, lparam);} bool callback colorscrdlg (hwnd hdlg, uint message, wparam, lparam) {static int icolor [3]; hwnd hwndparent, hctrl; int ictrlid, iindex; Switch (Message) {Case wm_initdialog: For (ictrlid = 10; ictrlid <13; ictrlid ++) {// The ictrlid corresponds to the resource. // obtain the handle hctrl = getdlgitem (hdlg, ictrlid); // set the range setscrollrange (hctrl, sb_ctl, 0,255, false ); // set the starting point setscrollpos (hctrl, sb_ctl, 0, false);} return true; Case wm_vscroll: // What lparam passes in is the handle hctrl = (hwnd) lparam; // get the ID, hctrl here is the window on the three scroll bars ictrlid = getwindowlong (hctrl, gwl_id); iindex = iCtrlID-10; // hwndparent is the window handle that shows color changes hwndparent = getparent (hdlg); // wparam low is control switch (loword (wparam )) {// if there is no break after this case statement, the sb_linedown will be triggered to move 1 down. // you can determine whether the result is the lowest case sb_pagedown: icolor [iindex] + = 15; // click the case sb_linedown button on the scroll bar: icolor [iindex] = min (255, icolor [iindex] + 1); break; Case sb_pageup: icolor [iindex]-= 15; Case sb_lineup: icolor [iindex] = max (0, icolor [iindex]-1); break; Case sb_top: icolor [iindex] = 0; break; Case sb_bottom: icolor [iindex] = 255; break; Case sb_thumbposition: Case sb_thumbtrack: // icolor [iindex] = hiword (wparam); break; default: Return false;} setscrollpos (hctrl, sb_ctl, icolor [iindex], true); // set the number setdlgitemint (hdlg, ictrlid + 3, icolor [iindex], false); // Replace the class-related background brush, delete the returned brush handle deleteobject (hgdiobj) setclasslong (hwndparent, gcl_hbrbackground, (long) createsolidbrush (RGB (icolor [0], icolor [1], icolor [2]); // re-paint invalidaterect (hwndparent, null, true); Return true ;} return false ;}