code improve

Author: Shen-wb

1.hello-world/1.minimum-code.html

@@ -28,9 +28,10 @@ <h1 style="font-size: 1.5em;">Read Barcodes from a Camera</h1>
 
         /** LICENSE ALERT - THE END */
 
+        let pScanner = null;
         document.getElementById('btn-show-scanner').onclick = async function() {
             try {
-                const scanner = await Dynamsoft.DBR.BarcodeScanner.createInstance();
+                const scanner = await (pScanner = pScanner || Dynamsoft.DBR.BarcodeScanner.createInstance());
                 /* 
                  * onFrameRead is triggered after the library finishes reading a frame.
                  * There can be multiple barcodes on one frame.

1.hello-world/10.read-video-pwa/helloworld-pwa.html

@@ -28,7 +28,8 @@ <h1 style="font-size: 1.5em;">Hello World for PWA</h1>
         // Dynamsoft.DBR.BarcodeReader.license = "YOUR-ORGANIZATION-ID or YOUR-HANDSHAKECODE or AN-OFFLINE-LICENSE or ANY-OTHER-TYPE-OF-SUPPORTED-LICENSE-STRING";
 
         /** LICENSE ALERT - THE END */
-        
+
+        let pScanner = null;
         let latestResult = null;
         document.getElementById('readBarcode').onclick = async function() {
             Notification.requestPermission().then((result) => {
@@ -37,7 +38,7 @@ <h1 style="font-size: 1.5em;">Hello World for PWA</h1>
                 }
             });
             try {
-                const scanner = await Dynamsoft.DBR.BarcodeScanner.createInstance();
+                const scanner = await (pScanner = pScanner || Dynamsoft.DBR.BarcodeScanner.createInstance());
                 scanner.onFrameRead = results => {
                     console.log("Barcodes on one frame:");
                     for (let result of results) {

1.hello-world/11.read-video-requirejs.html

@@ -32,9 +32,10 @@ <h1 style="font-size: 1.5em;">Hello World for RequireJS</h1>
             /** LICENSE ALERT - THE END */
 
             BarcodeReader.engineResourcePath = "https://cdn.jsdelivr.net/npm/dynamsoft-javascript-barcode@8.8.7/dist/";
+            let pScanner = null;
             document.getElementById('readBarcode').onclick = async function() {
                 try {
-                    const scanner = await BarcodeScanner.createInstance();
+                    const scanner = await (pScanner = pScanner || BarcodeScanner.createInstance());
                     scanner.onFrameRead = results => {
                         console.log("Barcodes on one frame:");
                         for (let result of results) {

1.hello-world/12.minimum-code-es6.html

@@ -37,9 +37,11 @@ <h1 style="font-size: 1.5em;">Read Barcodes from a Camera</h1>
 
         BarcodeRender.engineResourcePath = "https://cdn.jsdelivr.net/npm/dynamsoft-javascript-barcode@8.8.7/dist/";
 
+
+        let pScanner = null;
         document.getElementById('btn-show-scanner').addEventListener('click', async () => {
             try {
-               const scanner = await BarcodeScanner.createInstance();
+                const scanner = await (pScanner = pScanner || Dynamsoft.DBR.BarcodeScanner.createInstance());
                 /* 
                  * onFrameRead is triggered after the library finishes reading a frame.
                  * There can be one or multiple barcodes on each frame.

1.hello-world/12.read-video-webpack/src/index.js

@@ -16,10 +16,11 @@ import DBR from "dynamsoft-javascript-barcode";
 
 DBR.BarcodeReader.engineResourcePath = "https://cdn.jsdelivr.net/npm/dynamsoft-javascript-barcode@8.8.7/dist/";
 
+let pScanner = null;
 if (document.getElementById('readBarcode')) {
     document.getElementById('readBarcode').onclick = async function() {
         try {
-            const scanner = await Dynamsoft.DBR.BarcodeScanner.createInstance();
+            const scanner = await (pScanner = pScanner || DBR.BarcodeScanner.createInstance());
             scanner.onFrameRead = results => {
                 console.log("Barcodes on one frame:");
                 for (let result of results) {

1.hello-world/3.read-video-angular/src/app/img-decode/img-decode.component.ts

@@ -13,8 +13,8 @@ export class ImgDecodeComponent implements OnInit {
 
   decodeImg = async (e: any) => {
     try {
-      const render = await (this.pReader = DBR.BarcodeScanner.createInstance());
-      const results = await render.decode(e.target.files[0]);
+      const reader = await (this.pReader = DBR.BarcodeReader.createInstance());
+      const results = await reader.decode(e.target.files[0]);
       for (const result of results) {
         alert(result.barcodeText);
       }

1.hello-world/4.read-video-react/src/components/ImgDecode/ImgDecode.js

@@ -10,8 +10,8 @@ export default class ImgDecode extends Component {
 
   decodeImg = async (e) => {
     try {
-      const render = await (this.pReader = DBR.BarcodeScanner.createInstance());
-      let results = await render.decode(e.target.files[0]);
+      const reader = await (this.pReader = DBR.BarcodeReader.createInstance());
+      let results = await reader.decode(e.target.files[0]);
       for(let result of results){
         alert(result.barcodeText);
       }

1.hello-world/5.read-video-vue/src/components/ImgDecode.vue

@@ -14,8 +14,8 @@ export default {
   methods: {
     async decodeImg(e) {
       try {
-        const render = await (this.pReader = DBR.BarcodeScanner.createInstance());
-        let results = await render.decode(e.target.files[0]);
+        const reader = await (this.pReader = DBR.BarcodeReader.createInstance());
+        let results = await reader.decode(e.target.files[0]);
         for(let result of results){
           alert(result.barcodeText);
         }

1.hello-world/6.read-video-vue3/src/components/ImgDecode.vue

@@ -12,8 +12,8 @@ export default {
 
     const decodeImg = async (e) => {
       try {
-        const render = await (pReader.value = DBR.BarcodeScanner.createInstance());
-        let results = await render.decode(e.target.files[0]);
+        const reader = await (pReader.value = DBR.BarcodeReader.createInstance());
+        let results = await reader.decode(e.target.files[0]);
         for(let result of results){
           alert(result.barcodeText);
         }

1.hello-world/7.read-video-nextjs/components/ImgDecode.js

@@ -9,8 +9,8 @@ export default class ImgDecode extends Component {
 
   decodeImg = async (e) => {
     try {
-      const render = await (this.pReader = DBR.BarcodeScanner.createInstance());
-      let results = await render.decode(e.target.files[0]);
+      const reader = await (this.pReader = DBR.BarcodeReader.createInstance());
+      let results = await reader.decode(e.target.files[0]);
       for(let result of results){
         alert(result.barcodeText);     
       }