Getting Started with C++ Language

In this guide, you will learn step by step on how to build a barcode reading application with Dynamsoft Barcode Reader SDK using C++ language.

Requirements

Operating System:
- Windows 7, 8, 10, 11, 2003, 2008, 2008 R2, 2012, 2016, 2019, 2022
- Linux x64: Ubuntu 14.04.4+ LTS, Debian 8+, etc
- Linux arm 32bit
- Linux arm 64bit
- MacOS 64bit: 10.12+ (not included in the trial package, contact us to get the SDK)
Developing Tool
- Visual Studio 2008 or above
- G++ 5.4+

Note: Dynamsoft Barcode Reader provides both online and offline license options. The online license option might not work in an environment that doesn’t have network connection or some environments like AWS Lambda. In such case, you can get an offline trial license key via Customer Portal or by contacting us.

Installation

If you haven’t downloaded the SDK yet, download the C/C++ Package now from Dynamsoft website and unpack the package into the directory of your choice.

For this tutorial, we unpack it to [INSTALLATION FOLDER], change it to your unpacking path for the following content.

Build Your First Application

Let’s start by creating a console application which demonstrates how to use the minimum code to read barcodes from an image file.

You can download the entire source code here.

Create a New Project

For Windows

Open Visual Studio. Go to File > New > Project, create a new Empty Project and set Project name as DBRCPPSample.
Add a new source file named DBRCPPSample.cpp into the project.

For Linux/ARM/Mac

Create a new source file named DBRCPPSample.cpp and place it into the folder [INSTALLATION FOLDER]/Samples.

Include the Library

Add headers and libs in DBRCPPSample.cpp.

 #include<iostream>
 #include "[INSTALLATION FOLDER]/Include/DynamsoftBarcodeReader.h"
 using namespace std;
 using namespace dynamsoft::dbr;
 #if defined(_WIN64) || defined(_WIN32)
     #ifdef _WIN64
         #pragma comment(lib, "[INSTALLATION FOLDER]/Lib/Windows/x64/DBRx64.lib")
     #else
         #pragma comment(lib, "[INSTALLATION FOLDER]/Lib/Windows/x86/DBRx86.lib")
     #endif
 #endif

Initialize a Barcode Reader Instance

Initialize the license key.
```
 int errorCode = 0;
 char errorBuf[512];
 errorCode = CBarcodeReader::InitLicense("<insert DBR license key here>", errorBuf, 512);
 if (errorCode != DBR_OK)
 {
     // Add your code for license error processing;
     cout << errorBuf << endl;
 }
```
Please replace <insert DBR license key here> with a valid DBR licensekey. There are two ways to obtain one:
- Search InitLicense and find the license from [INSTALLATION FOLDER]/Samples/BarcodeReaderDemo/BarcodeReaderDemo.cpp.
- Request a trial license from Customer Portal.

Create an instance of Dynamsoft Barcode Reader.

 CBarcodeReader* dbr = new CBarcodeReader();

However, please note that if you are using a concurrent instance license, please use the new APIs GetInstance to initialize the barcode reader instance and then Recycle to allow for better concurrent instance management by the library.

 CBarcodeReader* dbr = CBarcodeReader::GetInstance();
 // If no instance is available right away, the application will wait until one becomes available
 if(dbr != NULL)
 {
     // Add your code here to call decoding method, process barcode results and so on
     // ...
     // Recycle the instance to make it idle for other concurrent tasks
     dbr->Recycle();
 }

Configure the Barcode Scanning Behavior

Set barcode format and count to read.
```
 char szErrorMsg[512];
 PublicRuntimeSettings settings;
 dbr->GetRuntimeSettings(&settings);
 settings.barcodeFormatIds = BF_PDF417; 
 settings.barcodeFormatIds_2 = BF2_DOTCODE; 
 settings.expectedBarcodesCount = 32;
 dbr->UpdateRuntimeSettings(&settings, szErrorMsg, 512);
```
The barcode formats to enable is highly application-specific. We recommend that you only enable the barcode formats your application requires. Check out Barcode Format Enumeration for full supported barcode formats.

If you know exactly the barcode count you want to read, specify expectedBarcodesCount to speed up the process and improve the accuracy.

The Barcode Reader SDK comes with a large array of runtime settings to optimize the performance of the library. To learn about all the runtime settings, please visit the RuntimeSettings API page. To learn more about the cases and situations in which the settings can help, please visit the Explore Features page.

Decode and Output Results

Decode barcodes from an image file.
```
 int errorCode = -1;
 errorCode = dbr->DecodeFile("[INSTALLATION FOLDER]/Images/AllSupportedBarcodeTypes.png", "");
 if(errorCode != DBR_OK)
     cout << CBarcodeReader::GetErrorString(errorCode) << endl;
```
For the error handling mechanism, the SDK returns Error Code for each function and provides a function GetErrorString to get the readable message. You should add codes for error handling based on your needs. Check out Error Code for full supported error codes.

Get and output barcode results.

 TextResultArray* pResult = NULL;
 dbr->GetAllTextResults(&pResult);
 if (pResult != NULL && pResult->resultsCount > 0)
 {
     cout << pResult->resultsCount <<" total barcode(s) found."<< endl;
     for (int iIndex = 0; iIndex < pResult->resultsCount; iIndex++)
     {
         cout << "Result " << iIndex + 1 << endl;
         cout << "Barcode Format: " << pResult->results[iIndex]->barcodeFormatString << endl;
         cout << "Barcode Text: " << pResult->results[iIndex]->barcodeText << endl;
     }
 }
 cin.ignore();

The SDK returns multiple barcode information, including barcode count, barcode format, barcode text, location, barcode raw data, etc. Check out TextResult for full supported result data.

Release Allocated Memory

Release the allocated memory for the barcode results.

 if(pResult != NULL)           
     CBarcodeReader::FreeTextResults(&pResult);

Release the allocated memory for the instance.
```
 if(dbr != NULL)           
     delete dbr;
```
However, please note that if you are using a concurrent instance license, please use the new APIs Recycle to allow for better concurrent instance management by the library.
```
 if(dbr != NULL)           
     dbr->Recycle();
```

Note:
Please change all [INSTALLATION FOLDER] in above code snippet to your unpacking path.

Build and Run the Project

For Windows

In Visual Studio, set the solution to build as Release|x64.
Build the project to generate program DBRCPPSample.exe.
Copy ALL *.dll files under [INSTALLATION FOLDER]\Lib\Windows\x64 to the same folder as the DBRCPPSample.exe.
Run the program DBRCPPSample.exe.

The SDK supports both x86 and x64, please set the platform based on your needs.

For Linux/ARM/Mac

Open a terminal and change to the target directory where DBRCPPSample.cpp located in. Build the sample:
```
 g++ -o DBRCPPSample DBRCPPSample.cpp -lDynamsoftBarcodeReader -L ../Lib/Linux -Wl,-rpath=../Lib/Linux -std=c++11
```
Please replace Linux to ARM32 or ARM64 based on your platform.
Run the program DBRCPPSample.
```
 ./DBRCPPSample
```

You can download the entire source code here.

Next Steps

Learn How to Upgrade to Latest Version
Explore SDK Features
See how the SDK works in Popular Use Cases
Check out the Official Samples and Demo