使用c++調(diào)用windows打印api進(jìn)行打印的示例代碼
前言
在近期開發(fā)的收銀臺項目中,需要使用打印機(jī)進(jìn)行小票打印,打印流程的時序圖如下所示:
在客戶的使用過程中,遇到一個問題,如果機(jī)器安裝了打印機(jī)驅(qū)動,那么調(diào)用廠商提供的 sdk 進(jìn)行打印的話,會導(dǎo)致出現(xiàn)小票只打印一半的情況,對此,需要繞過廠商 sdk 使用系統(tǒng)的打印才能夠解決這一問題。
在 web 端打印中,需要調(diào)用瀏覽器打印 api 進(jìn)行網(wǎng)頁打印。這意味著,之前后端編寫的esc/pos無法復(fù)用到,同時,前端還得花費(fèi)精力來編寫 html 以及css 來完成打印內(nèi)容的排版,這無疑增加了復(fù)雜度以及工作量。正打算開始時,得到高人指點(diǎn)。
可以使用 windows api 進(jìn)行打印
具體參見這篇文檔
于是開始這方面的研究,功夫不負(fù)有心人,使用 windows api 完成了系統(tǒng)的打印,于是編寫這篇文章記錄踩過的坑。
首先看看如何進(jìn)行打?。?br />
BOOL RawDataToPrinter(LPSTR szPrinterName, LPBYTE lpData, DWORD dwCount) { HANDLE hPrinter; DOC_INFO_1 DocInfo; DWORD dwJob; DWORD dwBytesWritten; // Need a handle to the printer. if (!OpenPrinter(szPrinterName, &hPrinter, NULL)) { int y = GetLastError(); cout << "openFail" << y << endl; return FALSE; } // Fill in the structure with info about this "document." DocInfo.pDocName = LPSTR("My Document\0"); DocInfo.pOutputFile = NULL; DocInfo.pDatatype = NULL; // LPWSTR("RAW\0"); // Inform the spooler the document is beginning. if ((dwJob = StartDocPrinter(hPrinter, 1, (LPBYTE)&DocInfo)) == 0) { int x = GetLastError(); cout << "StartDocPrinter Fail" << x << endl; ClosePrinter(hPrinter); return FALSE; } // Start a page. if (!StartPagePrinter(hPrinter)) { EndDocPrinter(hPrinter); ClosePrinter(hPrinter); return FALSE; } // Send the data to the printer. if (!WritePrinter(hPrinter, lpData, dwCount, &dwBytesWritten)) { EndPagePrinter(hPrinter); EndDocPrinter(hPrinter); ClosePrinter(hPrinter); return FALSE; } // End the page. if (!EndPagePrinter(hPrinter)) { EndDocPrinter(hPrinter); ClosePrinter(hPrinter); return FALSE; } // Inform the spooler that the document is ending. if (!EndDocPrinter(hPrinter)) { ClosePrinter(hPrinter); return FALSE; } // Tidy up the printer handle. ClosePrinter(hPrinter); // Check to see if correct number of bytes were written. if (dwBytesWritten != dwCount) return FALSE; return TRUE; }
在對照,發(fā)現(xiàn)是 handle 是無效的,也就意味這 OpenPrinter 這一步驟沒有打開需要的打印機(jī)。于是嘗試使用 設(shè)備與打印機(jī)中的打印機(jī)名稱,還真就連上了,成功調(diào)用打印服務(wù)。
但客戶電腦上的打印機(jī)名稱是不固定的,不能使用固定打印機(jī)名稱,所以得拿到已經(jīng)連接了的打印機(jī)列表,于是搜索到了 EnumPrinters 這一api,具體用法如下:
void getPrinterList() { PRINTER_INFO_2* printerList; unsigned char size; unsigned long pcbNeeded; unsigned long pcReturned; EnumPrinters(PRINTER_ENUM_LOCAL, NULL, 2, NULL, 0, &pcbNeeded, &pcReturned); if ((printerList = (PRINTER_INFO_2*)malloc(pcbNeeded)) == 0) { return; } if (!EnumPrinters(PRINTER_ENUM_LOCAL, NULL, 2, (LPBYTE)printerList, pcbNeeded, &pcbNeeded, &pcReturned)) { free(printerList); return; } for (int i = 0; i < (int)pcReturned; i++) { string printName(printerList[i].pPrinterName); if (printerList[i].Attributes & PRINTER_ATTRIBUTE_NETWORK) { cout << "網(wǎng)絡(luò)打印機(jī)" << printName << endl; } else { cout << "本地打印機(jī)" << printName << endl; } } cout << "number " << pcReturned << endl; }
通過這一方式,的確獲取到了系統(tǒng)中可用的打印機(jī),可是拿到可用的打印機(jī)后還是有一個問題:“如何知道哪一個是小票打印機(jī)”?
為此又進(jìn)行了搜索,又找到了一個 api GetDefaultPrinter,用法如下:
string getDefaultPrinterName() { DWORD size = 0; GetDefaultPrinter(NULL, &size); if (size) { TCHAR* buffer = new TCHAR[size]; GetDefaultPrinter(buffer, &size); string printerName(buffer); return printerName; } else { return ""; } }
通過此方法獲取到系統(tǒng)默認(rèn)打印機(jī),客戶只需要設(shè)置默認(rèn)的打印機(jī)為小票打印機(jī)就完美解決問題了。
以下是完整代碼:
#include <iostream> #include <windows.h> #include "node.h" #include "base64.h" using namespace std; using v8::FunctionCallbackInfo; using v8::Isolate; using v8::Local; using v8::NewStringType; using v8::Object; using v8::String; using v8::Value; using v8::Integer; using v8::Int8Array; BOOL RawDataToPrinter(LPSTR szPrinterName, LPBYTE lpData, DWORD dwCount); string getDefaultPrinterName(); void localPrintRawData(const FunctionCallbackInfo<Value>& args) { Isolate* isolate = args.GetIsolate(); Local<v8::Context> context = isolate->GetCurrentContext(); v8::String::Utf8Value portString(isolate, args[0]); std::string base64Str(*portString); vector<BYTE> bytes = base64_decode(base64Str); char* buffer = new char[bytes.size()]; copy(bytes.begin(), bytes.end(), buffer); string printerName = getDefaultPrinterName(); if (printerName.size() > 0) { printerName += "\0"; wstring ws(printerName.begin(), printerName.end()); RawDataToPrinter(const_cast<char*>(printerName.c_str()), &bytes[0], bytes.size()); } else { cout << "no printer" << endl; } } BOOL RawDataToPrinter(LPSTR szPrinterName, LPBYTE lpData, DWORD dwCount) { HANDLE hPrinter; DOC_INFO_1 DocInfo; DWORD dwJob; DWORD dwBytesWritten; // Need a handle to the printer. if (!OpenPrinter(szPrinterName, &hPrinter, NULL)) { int y = GetLastError(); cout << "openFial" << y << endl; return FALSE; } // Fill in the structure with info about this "document." DocInfo.pDocName = LPSTR("My Document\0"); DocInfo.pOutputFile = NULL; DocInfo.pDatatype = NULL; // LPWSTR("RAW\0"); // Inform the spooler the document is beginning. if ((dwJob = StartDocPrinter(hPrinter, 1, (LPBYTE)&DocInfo)) == 0) { int x = GetLastError(); cout << "StartDocPrinter Fial" << x << endl; ClosePrinter(hPrinter); return FALSE; } // Start a page. if (!StartPagePrinter(hPrinter)) { EndDocPrinter(hPrinter); ClosePrinter(hPrinter); return FALSE; } // Send the data to the printer. if (!WritePrinter(hPrinter, lpData, dwCount, &dwBytesWritten)) { EndPagePrinter(hPrinter); EndDocPrinter(hPrinter); ClosePrinter(hPrinter); return FALSE; } // End the page. if (!EndPagePrinter(hPrinter)) { EndDocPrinter(hPrinter); ClosePrinter(hPrinter); return FALSE; } // Inform the spooler that the document is ending. if (!EndDocPrinter(hPrinter)) { ClosePrinter(hPrinter); return FALSE; } // Tidy up the printer handle. ClosePrinter(hPrinter); // Check to see if correct number of bytes were written. if (dwBytesWritten != dwCount) return FALSE; return TRUE; } void getPrinterList() { PRINTER_INFO_2* printerList; unsigned char size; unsigned long pcbNeeded; unsigned long pcReturned; EnumPrinters(PRINTER_ENUM_LOCAL, NULL, 2, NULL, 0, &pcbNeeded, &pcReturned); if ((printerList = (PRINTER_INFO_2*)malloc(pcbNeeded)) == 0) { return; } if (!EnumPrinters(PRINTER_ENUM_LOCAL, NULL, 2, (LPBYTE)printerList, pcbNeeded, &pcbNeeded, &pcReturned)) { free(printerList); return; } for (int i = 0; i < (int)pcReturned; i++) { string printName(printerList[i].pPrinterName); if (printerList[i].Attributes & PRINTER_ATTRIBUTE_NETWORK) { cout << "網(wǎng)絡(luò)打印機(jī)" << printName << endl; } else { cout << "本地打印機(jī)" << printName << endl; } } cout << "number " << pcReturned << endl; } string getDefaultPrinterName() { DWORD size = 0; GetDefaultPrinter(NULL, &size); if (size) { TCHAR* buffer = new TCHAR[size]; GetDefaultPrinter(buffer, &size); string printerName(buffer); return printerName; } else { return ""; } } void Initialize(Local<Object> exports) { NODE_SET_METHOD(exports, "localPrintRawData", localPrintRawData); } NODE_MODULE(zq_device, Initialize)
參考:
https://docs.microsoft.com/en-us/windows/win32/printdocs/openprinter
https://stackoverflow.com/questions/6682286/understanding-a-c-sample-printers-handles-strings
https://docs.microsoft.com/en-us/windows/win32/debug/system-error-codes--0-499-
到此這篇關(guān)于使用c++調(diào)用windows打印api進(jìn)行打印的示例代碼的文章就介紹到這了,更多相關(guān)c++ 調(diào)用windows打印內(nèi)容請搜索腳本之家以前的文章或繼續(xù)瀏覽下面的相關(guān)文章希望大家以后多多支持腳本之家!
相關(guān)文章
用pybind11封裝C++實現(xiàn)的函數(shù)庫的方法示例
這篇文章主要介紹了用pybind11封裝C++實現(xiàn)的函數(shù)庫,文中通過示例代碼介紹的非常詳細(xì),對大家的學(xué)習(xí)或者工作具有一定的參考學(xué)習(xí)價值,需要的朋友們下面隨著小編來一起學(xué)習(xí)學(xué)習(xí)吧2020-02-02C++實現(xiàn)LeetCode(68.文本左右對齊)
這篇文章主要介紹了C++實現(xiàn)LeetCode(68.文本左右對齊),本篇文章通過簡要的案例,講解了該項技術(shù)的了解與使用,以下就是詳細(xì)內(nèi)容,需要的朋友可以參考下2021-07-07C語言編程數(shù)據(jù)結(jié)構(gòu)基礎(chǔ)詳解小白篇
這篇文章主要介紹了數(shù)據(jù)結(jié)構(gòu)的基礎(chǔ),非常適合初學(xué)數(shù)據(jù)結(jié)構(gòu)的小白,有需要的朋友可以借鑒參考下,希望可以有所幫助,祝大家多多進(jìn)步,早日升職加薪2021-09-09