findfirstprinterchangenotification 示例.docx

findfirstprinterchangenotification 示例
在Windows操作系统中，FindFirstPrinterChangeNotification 是一个 API 函数，用于监视打印机的状态更改。当打印机状态发生更改时（例如，打印机被添加、删除或配置更改），该函数会返回一个事件通知。
以下是一个简单的示例，演示如何使用 FindFirstPrinterChangeNotification：
cpp复制代码

#include <windows.h>

#include <stdio.h>

DWORD CALLBACK PrinterChangeNotificationProc(

DWORD dwFlags,

DWORD dwEvent,

LPVOID lpEventData,

LPVOID lpArg

) {

UNREFERENCED_PARAMETER(dwFlags);

UNREFERENCED_PARAMETER(dwEvent);

UNREFERENCED_PARAMETER(lpEventData);

if (dwFlags & PRINTER_CHANGE_ADD) {

printf("Printer added\n");

} else if (dwFlags & PRINTER_CHANGE_DELETE) {

printf("Printer deleted\n");

} else if (dwFlags & PRINTER_CHANGE_SET_PRINTER) {

printf("Printer settings changed\n");

} else {

printf("Unknown printer change\n");

}

return 0;

}

int main() {

HANDLE hPrinterChangeNotify = NULL;

DWORD result = 0;

DWORD bytesReturned = 0;

DWORD flags = PRINTER_CHANGE_ADD | PRINTER_CHANGE_DELETE | PRINTER_CHANGE_SET_PRINTER;

BOOL success = FindFirstPrinterChangeNotification(NULL, flags, 0, &hPrinterChangeNotify);

if (success) {

SetPrinterChangeNotificationProc(hPrinterChangeNotify, PrinterChangeNotificationProc, NULL);

while (FindNextPrinterChangeNotification(hPrinterChangeNotify, &result, &bytesReturned, NULL, NULL)) {

if (result == ERROR_INVALID_FUNCTION) {

break; // End of notifications.

} else if (result == ERROR_SUCCESS) {

// Continue processing notifications.

} else {

printf("Error: %d\n", result);

break; // An error occurred. Exit the loop.

}

}

FindClosePrinterChangeNotification(hPrinterChangeNotify);

} else {

printf("Failed to start printer change notifications\n");

}

return 0;

}
注意：为了使该示例正常工作，您需要链接到 printui.lib 库，并确保在编译时包括正确的头文件。此外，此代码需要在管理员权限下运行，因为监视打印机更改通常需要高级权限。