Windows communication mechanism and DLL Mechanism

DLL

<1> event. h

#include<windows.h>#include<math.h>#ifndef LIB_H#define LIB_Hextern "C" void  _declspec(dllexport)setCalculate(HWND  hwnd,HWND  hwnd1,HWND  hwnd2,HWND  hwnd3,HWND  hwnd4);extern "C" void  _declspec(dllexport)setClearAll(HWND  hwnd1,HWND  hwnd2,HWND  hwnd3,HWND  hwnd4);#endif

 

<2> event. cpp

# Include "event. H "char money [] =" "; char rate [] =" "; char year [] =" "; char total [] = ""; /* ++ ++ * main function: check ++ * function: Input judgment function ++ * parameter: A [] input string ++ * return value: returns true if it is all numeric values. Otherwise, returns false +++ ++ ++ * /bool check (char a []) {int I; int Len = strlen (a); for (I = 0; I <Len; I ++) {if (a [I]> '9' | A [I] <'0') {return false ;}} return true ;} /* ++ ++ * main function: setcalculate ++ * function: Add a response for calculatebutton + input principal, interest rate, and total annual output amount + + * parameter: hwnd parent window handle + hwnd1 principal input box handle + hwnd2 interest rate input box handle + hwnd3 years input box handle + hwnd4 output box handle + * return value: ++ ++ */void setcalculate (hwnd, hwnd hwnd1, hwnd hwnd2, hwnd hwnd3, hwnd hwnd4) {getwindowtext (hwnd1, money, 20); getwindowtext (hwnd2, rate, 20); getwindowtext (hwnd3, year, 20 ); double totalmoney; If (check (money) & check (rate) & check (year) {totalmoney = atof (money) * POW (1/atof (Rate) + 1, atoi (year); gcvt (totalmoney, 10, total); setwindowtext (hwnd4, total);} else {MessageBox (hwnd, text ("sorry, the format you entered is not "), text (" prompt "), mb_ OK); setwindowtext (hwnd1," "); setwindowtext (hwnd2," "); setwindowtext (hwnd3, ""); setwindowtext (hwnd4 ,"");}} /* ++ ++ * main function: setclearall ++ * function: Add a response for clearbutton + + clear all input box output box + + * parameter: hwnd1 principal input box handle + hwnd2 interest rate input box handle + hwnd3 years input box handle + hwnd4 output box handle + * return value: ++ ++ */void setclearall (hwnd hwnd1, hwnd hwnd2, hwnd hwnd3, hwnd hwnd4) {setwindowtext (hwnd1, ""); setwindowtext (hwnd2, ""); setwindowtext (hwnd3, ""); setwindowtext (hwnd4, "");}

 

Window

<1> window. h

// Windows program header file # include <windows. h> extern char sztitle []; // Title Bar string extern char szwindowclass []; // window class name extern char szmenuname []; extern int ID, id_1; // function prototype declaration atom initapplication (hinstance); // used to register the window class bool initinstance (hinstance, INT); // used to create the main window lresult callback wndproc (hwnd, uint, wparam, lparam); // message processing function int apientry winmain (hinstance, hinstance, lpstr, INT); // main function bool createcontrol (hinstance, hwnd, lpstr); // create a text box

 

<2> window. cpp

# Include "window. H "# include <math. h> // global variable char sztitle [] = "Windows communication mechanism and DLL mechanism"; // Title string char szwindowclass [] = "W32 "; // window class name char szmenuname [] = "null"; // menu name typedef void (* lpsetcalculatefun) (hwnd, hwnd ); typedef void (* lpsetclearallfun) (hwnd, hwnd); hwnd hwnd1, hwnd2, hwnd3, hwnd4, calculatebutton, clearbutton; hwnd; /* ++ ++ ++ * Main function: winmain ++ * function: the initialization and registration window class creates a window and enters the message loop and terminates the application. The ++ * parameter is as follows: the current hinstance instance ++ the previous instance of hprevinstance ++ the lpcmdline command line ++ ncmdshow selects the display window or icon ++ * return value: MSG. wparam ++ ++ +++ */INT apientry winmain (hinstance, hinstance hprevinstance, lpstr lpcmdline, int ncmdshow) {MSG; // declare the message structure object initap Plication (hinstance); // registration window if (! Initinstance (hinstance, ncmdshow) // initialize {return false;} while (getmessage (& MSG, (hwnd) null, 0, 0 )) // message loop {translatemessage (& MSG); // retrieves the message dispatchmessage (& MSG); // indirectly transmits the message to the function pointer} return MSG. wparam; // The End message is sent back to postquitmesage in a loop}/* ++ ++ ++ * main function: initapplication ++ * function: used to register the window class ++ * parameter: hinstance current instance ++ * return value: if the operation succeeds, a unique integer is returned. If the operation fails, 0 ++ is returned. ++ ++ */Atom initapplication (hinstance) {wndclass WC; // declare the window structure object // initialize the object's Domain value WC. style = cs_hredraw | cs_vredraw; // if the size of the redrawing window is changed, the WC. lpfnwndproc = wndproc; // window message processing function WC. cbclsextra = 0; // No additional window class memory WC. cbwndextra = 0; // No additional window memory WC. hinstance = hinstance; // The WC of the current instance. hicon = loadicon (null, idi_application); // icon WC. hcursor = loadcur Sor (null, idc_arrow); // pointer WC. hbrbackground = (hbrush) getstockobject (white_brush); // background painter WC. lpszclassname = szwindowclass; // window class name WC. lpszmenuname = szmenuname; // menu name return registerclass (& WC ); // register}/* ++ ++ * main function: initinstance ++ * function: used to create the main window + * parameter: hinstance current instance + + ncmdshow select display window or icon + + * return value: If successful, a non-zero value is returned, if the request fails, 0 ++ is returned. ++ ++ */Bool initinstance (hinstance, int ncmdshow) {// declare window handle hwnd = createwindow (szwindowclass, // window class name, use the registered main window class sztitle, // window name, ws_overlappedwindow | ws_vscroll | ws_hscroll, which is displayed on the title bar of the window. // The display mode supports horizontal and vertical scrolling of cw_usedefault, // X starting coordinate of cw_usedefault, // y starting coordinate of 400, // 300 in width, // null in height, // null in the non-parent window, // hinstance in the menu handle, // null in the instance handle // No window creation count Data); If (! Hwnd) // determine whether the creation is successful {return false;} createcontrol (hinstance, hwnd, null); showwindow (hwnd, ncmdshow ); // The Window updatewindow (hwnd) is displayed after the creation is successful; // return true when the wm_paint message is sent ;} /* ++ ++ * main function: createcontrol ++ * function: Create a text box + * parameter: hwndp parent window handle + + sztitle window title + + * return value: ++ ++ */bool createcontrol (H Instance hinstance, hwnd hwndp, lpstr sztitle) {hwnd1 = createwindow ("edit", null, ws_child | ws_visible | ws_border, 50, 40,100, 20, hwndp, null, hinstance, null); calculatebutton = createwindow ("button", "calculation", ws_child | ws_visible | ws_border, 180, 20, hwndp, null, hinstance, null ); clearbutton = createwindow ("button", "clear", ws_child | ws_visible | ws_border, 180, 60, 20, hwndp, null, hinstance, NUL L); hwnd2 = createwindow ("edit", null, ws_child | ws_visible | ws_border, 50, 70,100, 20, hwndp, null, hinstance, null ); hwnd3 = createwindow ("edit", null, ws_child | ws_visible | ws_border, 50,100,100, 20, hwndp, null, hinstance, null); hwnd4 = createwindow ("edit", null, ws_child | ws_visible | ws_vscroll | ws_border | es_left | es_multiline | es_autovscroll, 50,130,300,100, hwndp, null, hinstance, null); showwind Ow (hwnd1, sw_show); showwindow (calculatebutton, sw_show); showwindow (clearbutton, sw_show); showwindow (hwnd2, sw_show); showwindow (hwnd3, sw_show); showwindow (hwnd4, sw_show); Return true ;} /* ++ ++ * main function: wndproc ++ * function: Message Processing Function ++ * parameter: hwnd instance handle + message + + domain in wparam MSG message structure + + domain in lparam MSG message structure + * return value: 0 ++ ++ ++ */Lresult callback wndproc (hwnd, uint message, wparam, lparam) {paintstruct pS; HDC; Switch (Message) {Case wm_paint: HDC = beginpaint (hwnd, & PS); textout (HDC, 150, 10, "interest calculator", strlen ("interest calculator"); textout (HDC, 10, 40, "principal:", strlen ("principal:"); textout (HDC, 10, 70, "Interest Rate:", strlen ("Interest Rate:"); textout (HDC, 10,100, "year:", strlen ("year:"); endpa INT (hwnd, & PS); break; Case wm_command: hinstance hdll; lpsetcalculatefun setcalculatefun; lpsetclearallfun setclearallfun; hdll = loadlibrary (".. \ dll \ debug \ DLL. DLL "); // obtain the DLL module handle if (hdll! = NULL) {setcalculatefun = (Counter) getprocaddress (hdll, "setcalculate"); // get the export address of the function setclearallfun = (lpsetclearallfun) getprocaddress (hdll, "setclearall "); // obtain the function export address if (setcalculatefun! = NULL) {If (loword (lparam) = loword (calculatebutton) {setcalculatefun (hwnd, hwnd1, hwnd2, hwnd3, hwnd4) ;}} if (setclearallfun! = NULL) {If (loword (lparam) = loword (clearbutton) {setclearallfun (hwnd1, hwnd2, hwnd3, hwnd4) ;}} freelibrary (hdll );} else {MessageBox (hwnd, text ("hdll creation failed"), text ("prompt"), mb_ OK) ;}break; Case wm_destroy: postquitmessage (0); break; default: Return defwindowproc (hwnd, message, wparam, lparam);} return 0 ;}