findfirstprinterchangenotification示例在Windows操作系統(tǒng)中，F(xiàn)indFirstPrinterChangeNotification

是一個(gè)API函數(shù)，用于監(jiān)視打印機(jī)的狀態(tài)更改。當(dāng)打印機(jī)狀態(tài)發(fā)生更改時(shí)（例如，打印機(jī)被添加、刪除或配置更改），該函數(shù)會(huì)返回一個(gè)事件通知。以下是一個(gè)簡(jiǎn)單的示例，演示如何使用

FindFirstPrinterChangeNotification：cpp復(fù)制代碼#include<windows.h>#include<stdio.h>DWORDCALLBACKPrinterChangeNotificationProc(DWORDdwFlags,DWORDdwEvent,LPVOIDlpEventData,LPVOIDlpArg){UNREFERENCED_PARAMETER(dwFlags);UNREFERENCED_PARAMETER(dwEvent);UNREFERENCED_PARAMETER(lpEventData);if(dwFlags&PRINTER_CHANGE_ADD){printf("Printeradded\n");}elseif(dwFlags&PRINTER_CHANGE_DELETE){printf("Printerdeleted\n");}elseif(dwFlags&PRINTER_CHANGE_SET_PRINTER){printf("Printersettingschanged\n");}else{printf("Unknownprinterchange\n");}return0;}intmain(){HANDLEhPrinterChangeNotify=NULL;DWORDresult=0;DWORDbytesReturned=0;DWORDflags=PRINTER_CHANGE_ADD|PRINTER_CHANGE_DELETE|PRINTER_CHANGE_SET_PRINTER;BOOLsuccess=FindFirstPrinterChangeNotification(NULL,flags,0,&hPrinterChangeNotify);if(success){SetPrinterChangeNotificationProc(hPrinterChangeNotify,PrinterChangeNotificationProc,NULL);while(FindNextPrinterChangeNotification(hPrinterChangeNotify,&result,&bytesReturned,NULL,NULL)){if(result==ERROR_INVALID_FUNCTION){break;//Endofnotifications.}elseif(result==ERROR_SUCCESS){//Continueprocessingnotifications.}else{printf("Error:%d\n",result);break;//Anerroroccurred.Exittheloop.}}FindClosePrinterChangeNotification(hPrinterChangeNotify);}else{printf("Failedtostartprinterchangenotifications\n");}return0;}注意：