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Dynamsoft/barcode-reader-javascript: Dynamsoft Barcode Reader JavaScript SDK for ...

原作者: [db:作者] 来自: 网络 收藏 邀请

开源软件名称：

Dynamsoft/barcode-reader-javascript

开源软件地址：

https://github.com/Dynamsoft/barcode-reader-javascript

开源编程语言：


开源软件介绍：

Barcode Reader for Your Website

Dynamsoft Barcode Reader JavaScript Edition is equipped with industry-leading algorithms for exceptional speed, accuracy and read rates in barcode reading. With its well-designed API, you can turn your web page into a barcode scanner with just a few lines of code.

version downloads jsdelivr vulnerabilities

Once integrated, your users can open your website in a browser, access their cameras and read barcodes directly from the video input.

In this guide, you will learn step by step on how to integrate this library into your website.

Table of Contents

Popular Examples

You can also:

Hello World - Simplest Implementation

Let's start with the "Hello World" example of the library which demonstrates how to use the minimum code to enable a web page to read barcodes from a live video stream.

Step One: Check the code of the example

The complete code of the "Hello World" example is shown below

<!DOCTYPE html>
<html>

<body>
    <script src="https://cdn.jsdelivr.net/npm/[email protected]/dist/dbr.js"></script>
    <script>
        // Specifies a license, you can visit https://www.dynamsoft.com/customer/license/trialLicense?ver=9.0.2&utm_source=github&product=dbr&package=js to get your own trial license good for 30 days. 
        Dynamsoft.DBR.BarcodeScanner.license = 'DLS2eyJvcmdhbml6YXRpb25JRCI6IjIwMDAwMSJ9';
        // Initializes and uses the library
        (async () => {
            let scanner = await Dynamsoft.DBR.BarcodeScanner.createInstance();
            scanner.onFrameRead = results => {
                if (results.length > 0) console.log(results);
            };
            scanner.onUniqueRead = (txt, result) => {
                alert(txt);
            };
            await scanner.show();
        })();
    </script>
</body>

</html>

Code in Github   Run via JSFiddle   Run in Dynamsoft

About the code

  • license: This property specifies a license key. Note that the license "DLS2eyJvcmdhbml6YXRpb25JRCI6IjIwMDAwMSJ9" used in this example is an online license and requires network connection to work. Read more on Specify the license.

  • createInstance(): This method creates a BarcodeScanner object. This object can read barcodes directly from a video input with the help of its interactive UI (hidden by default) and the MediaDevices interface.

  • onFrameRead: This event is triggered every time the library finishes scanning a video frame. The results object contains all the barcode results that the library have found on this frame. In this example, we print the results to the browser console.

  • onUniqueRead: This event is triggered when the library finds a new barcode, which is not a duplicate among multiple frames. txt holds the barcode text value while result is an object that holds details of the barcode. In this example, an alert will be displayed for this new barcode.

  • show(): This method brings up the built-in UI of the BarcodeScanner object and starts scanning.

Step Two: Test the example

To test the example, you can open the copy deployed to Dynamsoft Server here. You will be asked to allow access to your camera, after which the video will be displayed on the page. After that, you can point the camera at a barcode to read it.

When a barcode is decoded, you will see the result text pop up and the barcode location will be highlighted in the video feed.

Alternatively, you can make a local test simply by taking the code in step 1, pasting it in a file with the name "hello-world.html" and open it in a browser.

Note:

If you open the web page as file:/// or http:// , the camera may not work correctly because the API getUserMedia usually requires HTTPS to access the camera.

To make sure your web application can access the camera, please configure your web server to support HTTPS. The following links may help.

  1. NGINX: Configuring HTTPS servers
  2. IIS: Create a Self Signed Certificate in IIS
  3. Tomcat: Setting Up SSL on Tomcat in 5 minutes
  4. Node.js: npm tls

If the test doesn't go as expected, you can contact us.

Building your own page

Include the library

Use a CDN

The simplest way to include the library is to use either the jsDelivr or UNPKG CDN. The "hello world" example above uses jsDelivr.

Host the library yourself

Besides using the CDN, you can also download the library and host its files on your own website / server before including it in your application.

Options to download the library:

Depending on how you downloaded the library and where you put it, you can typically include it like this:

<script src="/dynamsoft-barcode-reader-js-9.0.2/dist/dbr.js"></script>

or

<script src="/node_modules/dynamsoft-javascript-barcode/dist/dbr.js"></script>

Read more on how to host the library.

Configure the library

Before using the library, you need to configure a few things.

Specify the license

The library requires a license to work, use the API license to specify a license key.

Dynamsoft.DBR.BarcodeScanner.license = "YOUR-LICENSE-KEY";

To test the library, you can request a 30-day trial license via the customer portal.

If you registered a Dynamsoft account and downloaded the library from the official website, Dynamsoft will generate a 30-day trial license for you and put the license key into all the samples that come with the library.

Specify the location of the "engine" files

This is usually only required with frameworks like Angular or React, etc. where dbr.js is compiled into another file.

The purpose is to tell the library where to find the engine files (*.worker.js, *.wasm.js and *.wasm, etc.). The API is called engineResourcePath:

//The following code uses the jsDelivr CDN, feel free to change it to your own location of these files
Dynamsoft.DBR.BarcodeScanner.engineResourcePath = "https://cdn.jsdelivr.net/npm/[email protected]/dist/";

Interact with the library

Create a BarcodeScanner object

You can use one of two classes ( BarcodeScanner and BarcodeReader ) to interact with the library. BarcodeReader is a low-level class that processes images directly. BarcodeScanner , on the other hand, inherits from BarcodeReader and provides high-level APIs and a built-in GUI to allow continuous barcode scanning on video frames. We'll focus on BarcodeScanner in this guide.

To use the library, we first create a BarcodeScanner object.

Dynamsoft.DBR.BarcodeScanner.license = "YOUR-LICENSE-KEY";
let scanner = null;
try {
    scanner = await Dynamsoft.DBR.BarcodeScanner.createInstance();
} catch (ex) {
    console.error(ex);
}

Tip: When creating a BarcodeScanner object within a function which may be called more than once, it's best to use a "helper" variable to avoid double creation such as pScanner in the following code

Dynamsoft.DBR.BarcodeScanner.license = "YOUR-LICENSE-KEY";
let pScanner = null;
document.getElementById('btn-scan').addEventListener('click', async () => {
    try {
        const scanner = await (pScanner = pScanner || Dynamsoft.DBR.BarcodeScanner.createInstance());
    } catch (ex) {
        console.error(ex);
    }
});

Customize the BarcodeScanner Settings (optional)

Let's take a look at the following code snippets:

// Sets which camera and what resolution to use
let allCameras = await scanner.getAllCameras();
await scanner.setCurrentCamera(allCameras[0].deviceId);
await scanner.setResolution(1280, 720);
// Sets up the scanner behavior
let scanSettings = await scanner.getScanSettings();
// Disregards duplicated results found in a specified time period (in milliseconds)
scanSettings.duplicateForgetTime = 5000;
// Sets a scan interval in milliseconds so the library may release the CPU from time to time
// (setting this value larger is a simple way to save battery power and reduce device heating).
scanSettings.intervalTime = 100;
await scanner.updateScanSettings(scanSettings);
// Uses one of the built-in RuntimeSetting templates: "single" (decode a single barcode, the default mode), "speed", "balance" and "coverage"
await scanner.updateRuntimeSettings("speed");

// Makes changes to the template. The code below demonstrates how to specify enabled symbologies
let runtimeSettings = await scanner.getRuntimeSettings();
runtimeSettings.barcodeFormatIds = Dynamsoft.DBR.EnumBarcodeFormat.BF_ONED | Dynamsoft.DBR.EnumBarcodeFormat.BF_QR_CODE;
await scanner.updateRuntimeSettings(runtimeSettings);

Try in JSFiddle

As you can see from the above code snippets, there are three types of configurations:

  • Customize the data source: This configuration includes which camera to use, the preferred resolution, etc. Learn more here.

  • get/updateScanSettings: Configures the behavior of the scanner which includes duplicateForgetTime and intervalTime, etc.

  • get/updateRuntimeSettings: Configures the decode engine with either a built-in template or a comprehensive RuntimeSettings object. For example, the following uses the built-in "speed" settings with updated localizationModes.

Find the full list of the runtime settings here.

await barcodeScanner.updateRuntimeSettings("speed");
//await barcodeScanner.updateRuntimeSettings("balance"); //alternative
//await barcodeScanner.updateRuntimeSettings("coverage"); //alternative
let settings = await barcodeScanner.getRuntimeSettings();
settings.localizationModes = [
    Dynamsoft.DBR.EnumLocalizationMode.LM_CONNECTED_BLOCKS,
    Dynamsoft.DBR.EnumLocalizationMode.LM_SCAN_DIRECTLY,
    Dynamsoft.DBR.EnumLocalizationMode.LM_LINES, 0, 0, 0, 0, 0
];
await barcodeScanner.updateRuntimeSettings(settings);

Try in JSFiddle.

See also settings samples.

Customize the UI (optional)

The built-in UI of the BarcodeScanner object is defined in the file dist/dbr.ui.html . There are a few ways to customize it: