背景

提高扫码效率

理论

PDA扫码通过广播的方式推送给APP，更具PDA的提供的广播信道

filter.addAction("com.sunmi.scanner.ACTION_DATA_CODE_RECEIVED"); 和 intent.getByteArrayExtra("source_byte")

设置监听的广播和key

实现代码

padjs

// @/utils/pda.js  
const timeout = 5 * 1000; //扫码超时时间  

const main = plus.android.runtimeMainActivity();

// 全局只允许一个地方获取，存储最新的回调函数，获取完立即销毁  
let scanCallback = null;
//存储订阅，每个页面可以单独订阅，优先级低于scanCallback  
const subscriptions = [];

export const byteArrayToString = (array) => {
	return String.fromCharCode.apply(String, array);
};

const sleep = (ms) => {
	return new Promise((resolve) => setTimeout(resolve, ms));
};

export const registerReceiver = () => {
	//获取Android意图过滤类  
	const IntentFilter = plus.android.importClass("android.content.IntentFilter");
	//实例化意图过滤  
	const filter = new IntentFilter();
	//获取扫码成功的意图广播,    
	filter.addAction("com.sunmi.scanner.ACTION_DATA_CODE_RECEIVED");
	const receiver = plus.android.implements(
		"io.dcloud.feature.internal.reflect.BroadcastReceiver", {
			onReceive: function(context, intent) {
				plus.android.importClass(intent);
				console.log('intent', context, intent);
				const dataByte = intent.getByteArrayExtra("source_byte");
				console.log('dataByte', dataByte);
				const code = byteArrayToString(dataByte);
				console.log("receiver:" + code);
				if (scanCallback) {
					scanCallback(code);
				} else {
					subscriptions.forEach((cb) => cb(code));
				}
			},
		}
	);
	main.registerReceiver(receiver, filter);
};

export const openScan = () => {
	//获取Android意图类  
	let Intent = plus.android.importClass("android.content.Intent");
	//实例化意图  
	let intent = new Intent();
	//定义意图，由厂商提供  
	intent.setAction("com.sunmi.scanner.ACTION_DATA_CODE_RECEIVED");
	//广播这个意图  
	main.sendBroadcast(intent);
};

export const scanCode = async () => {
	uni.showLoading({
		title: "扫描中",
		mask: true
	});
	const getCode = () => {
		return new Promise((resolve) => {
			scanCallback = (code) => {
				resolve(code);
			};
		});
	};
	openScan();
	const res = await Promise.race([getCode(), sleep(timeout)]);
	scanCallback = null;
	uni.hideLoading();
	if (!res) {
		uni.showToast({
			icon: "none",
			title: "扫描失败",
		});
		throw new Error("扫描失败");
	}
	return res;
};

export const addSubscription = (callback) => {
	if (callback) {
		subscriptions.push(callback);
	}
};

export const removeSubscription = (callback) => {
	const index = subscriptions.findIndex((v) => v === callback);
	if (index > -1) {
		subscriptions.splice(index, 1);
	}
};

注册扫码事件

// appjs	
import {registerReceiver} from '@/utils/pda.js'

页面内使用

import { addSubscription, removeSubscription } from "@/utils/scan"; 
export default {  
onShow() {  
    if (this.onReceiveCode) {  
      addSubscription(this.onReceiveCode);  
    }  
  },  
  onHide() {  
    if (this.onReceiveCode) {  
      removeSubscription(this.onReceiveCode);  
    }  
  },  
  beforeDestroy() {  
    if (this.onReceiveCode) {  
      removeSubscription(this.onReceiveCode);  
    }  
  }
 }

其中

onReceiveCode(code) {
    // 自己的业务
}