我们有一个扫描仪应用程序，它有几个屏幕，其中有扫描仪组件。 当应用程序最初通过扫描仪组件加载到主屏幕上时，需要正常时间来初始化它，但是当我们从 & 切换到屏幕时，初始化时间比上一个屏幕增加了 2 倍。
扫描仪能够正确扫描数据，只是每次屏幕更改时初始化时间增加 2 倍。
我们使用的是 zebra et40 设备以及 datawedge 版本 11.3
我们正在使用
"react-native-datawedge-intents": "^0.1.8"以下是斑马扫描仪组件的代码
import React, { Component } from 'react';
import { DeviceEventEmitter } from 'react-native';
import DataWedgeIntents from 'react-native-datawedge-intents';
import { EventRegister } from 'react-native-event-listeners';
type Props = {
onScanned: Function,
};
export default class ZebraScanner extends Component<Props, {
ean8checked: boolean,
ean13checked: boolean,
code39checked: boolean,
code128checked: boolean,
lastApiVisible: boolean,
lastApiText: string,
checkBoxesDisabled: boolean,
scanButtonVisible: boolean,
dwVersionText: string,
activeProfileText: string,
enumeratedScannersText: string,
scans: [],
}> {
sendCommandResult: string;
broadcastReceiverHandler: (intent: any) => void;
constructor(props: Props) {
super(props)
this.state = {
ean8checked: true,
ean13checked: true,
code39checked: true,
code128checked: true,
lastApiVisible: false,
lastApiText: "Messages from DataWedge will go here",
checkBoxesDisabled: true,
scanButtonVisible: false,
dwVersionText: "Pre 6.3. Please create and configure profile manually. See the ReadMe for more details",
activeProfileText: "Requires DataWedge 6.3+",
enumeratedScannersText: "Requires DataWedge 6.3+",
scans: [],
};
this.sendCommandResult = "false";
this.broadcastReceiverHandler = (intent) => {
this.broadcastReceiver(intent);
}
DeviceEventEmitter.addListener('datawedge_broadcast_intent', this.broadcastReceiverHandler);
this.registerBroadcastReceiver();
this.determineVersion();
}
_onPressScanButton() {
this.sendCommand("com.symbol.datawedge.api.SOFT_SCAN_TRIGGER", 'TOGGLE_SCANNING');
}
determineVersion() {
this.sendCommand("com.symbol.datawedge.api.GET_VERSION_INFO", "");
}
setDecoders() {
// Set the new configuration
var profileConfig = {
"PROFILE_NAME": "ScannerDemo",
"PROFILE_ENABLED": "true",
"CONFIG_MODE": "UPDATE",
"PLUGIN_CONFIG": {
"PLUGIN_NAME": "BARCODE",
"PARAM_LIST": {
//"current-device-id": this.selectedScannerId,
"scanner_selection": "auto",
"decoder_ean8": "" + this.state.ean8checked,
"decoder_ean13": "" + this.state.ean13checked,
"decoder_code128": "" + this.state.code128checked,
"decoder_code39": "" + this.state.code39checked
}
}
};
this.sendCommand("com.symbol.datawedge.api.SET_CONFIG", profileConfig);
}
sendCommand(extraName: string, extraValue: any) {
const broadcastExtras: any = {};
broadcastExtras[extraName] = extraValue;
broadcastExtras["SEND_RESULT"] = this.sendCommandResult;
DataWedgeIntents.sendBroadcastWithExtras({
action: "com.symbol.datawedge.api.ACTION",
extras: broadcastExtras
});
}
registerBroadcastReceiver() {
DataWedgeIntents.registerBroadcastReceiver({
filterActions: [
'com.zebra.reactnativedemo.ACTION',
'com.symbol.datawedge.api.RESULT_ACTION'
],
filterCategories: [
'android.intent.category.DEFAULT'
]
});
}
broadcastReceiver(intent: any) {
// Broadcast received
if (intent.hasOwnProperty('RESULT_INFO')) {
const commandResult = intent.RESULT + " (" +
intent.COMMAND.substring(intent.COMMAND.lastIndexOf('.') + 1, intent.COMMAND.length) + ")";
this.commandReceived(commandResult.toLowerCase());
}
if (intent.hasOwnProperty('com.symbol.datawedge.api.RESULT_GET_VERSION_INFO')) {
// The version has been returned (DW 6.3 or higher). Includes the DW version along with other subsystem versions e.g MX
const versionInfo = intent['com.symbol.datawedge.api.RESULT_GET_VERSION_INFO'];
const datawedgeVersion = versionInfo['DATAWEDGE'];
// Fire events sequentially so the application can gracefully degrade the functionality available on earlier DW versions
if (datawedgeVersion >= "11.3")
this.datawedge113();
this.setState(this.state);
} else if (intent.hasOwnProperty('com.symbol.datawedge.api.RESULT_ENUMERATE_SCANNERS')) {
// Return from our request to enumerate the available scanners
const enumeratedScannersObj = intent['com.symbol.datawedge.api.RESULT_ENUMERATE_SCANNERS'];
this.enumerateScanners(enumeratedScannersObj);
} else if (intent.hasOwnProperty('com.symbol.datawedge.api.RESULT_GET_ACTIVE_PROFILE')) {
// Return from our request to obtain the active profile
const activeProfileObj = intent['com.symbol.datawedge.api.RESULT_GET_ACTIVE_PROFILE'];
this.activeProfile(activeProfileObj);
} else if (!intent.hasOwnProperty('RESULT_INFO')) {
// A barcode has been scanned
this.barcodeScanned(intent, new Date().toLocaleString());
}
}
datawedge113() {
// Create a profile for our application
this.sendCommand("com.symbol.datawedge.api.CREATE_PROFILE", "ScannerDemo");
this.setState({
dwVersionText: "11.3",
checkBoxesDisabled: false
});
// Configure the created profile (associated app and keyboard plugin)
var profileConfig = {
"PROFILE_NAME": "ScannerDemo",
"PROFILE_ENABLED": "true",
"CONFIG_MODE": "UPDATE",
"PLUGIN_CONFIG": {
"PLUGIN_NAME": "BARCODE",
"RESET_CONFIG": "true",
"PARAM_LIST": {
"configure_all_scanners": 'true',
"scanner_input_enabled": 'true',
"aim_type": '3',
"EXTRA_DATA": {
"aim_type": '3',
}
}
},
"APP_LIST": [{
"PACKAGE_NAME": "com.datawedgereactnative.demo",
"ACTIVITY_LIST": ["*"]
},
{
"PACKAGE_NAME": "com.demo",
"ACTIVITY_LIST": ["*"]
}]
};
this.sendCommand("com.symbol.datawedge.api.SET_CONFIG", profileConfig);
// Configure the created profile (intent plugin)
var profileConfig2 = {
"PROFILE_NAME": "ScannerDemo",
"PROFILE_ENABLED": "true",
"CONFIG_MODE": "UPDATE",
"PLUGIN_CONFIG": {
"PLUGIN_NAME": "INTENT",
"RESET_CONFIG": "true",
"PARAM_LIST": {
"intent_output_enabled": "true",
"intent_action": "com.zebra.reactnativedemo.ACTION",
"intent_delivery": "2"
}
}
};
this.sendCommand("com.symbol.datawedge.api.SET_CONFIG", profileConfig2);
// Give some time for the profile to settle then query its value
setTimeout(() => {
// Although we created the profile we can only configure it with DW 6.4.
this.sendCommand("com.symbol.datawedge.api.GET_ACTIVE_PROFILE", "");
// Enumerate the available scanners on the device
this.sendCommand("com.symbol.datawedge.api.ENUMERATE_SCANNERS", "");
// Functionality of the scan button is available
// this._onPressScanButton();
}, 1000);
}
commandReceived(commandText: string) {
this.setState(
{
lastApiText: commandText
}
);
this.setState(this.state);
}
enumerateScanners(enumeratedScanners: any) {
let humanReadableScannerList: string = "";
for (let i = 0; i < enumeratedScanners.length; i++) {
humanReadableScannerList += enumeratedScanners[i].SCANNER_NAME;
if (i < enumeratedScanners.length - 1)
humanReadableScannerList += ", ";
}
this.setState(
{
enumeratedScannersText: humanReadableScannerList,
}
)
}
activeProfile(theActiveProfile: any) {
this.setState({
activeProfileText: theActiveProfile
});
this.setState(this.state);
}
barcodeScanned(scanData: any, timeOfScan: any) {
// This is getting called after scanning code each time
const scannedData = scanData["com.symbol.datawedge.data_string"];
const scannedType = scanData["com.symbol.datawedge.label_type"];
EventRegister.emit('barcode_scanned', scannedData);
}
render() {
return (<></>);
}
}
以下是使用扫描仪组件的每个屏幕中的代码。
import React, { useState } from 'react';
import ZebraScanner from 'components/zebra-scanner';
const ScannerScreen = () => {
const [scannedText, setScannedText] = useState('No Data Scanned');
const onScanned = async (scannedData: any) => {
const scannedCode = scannedData.trim();
setScannedText(scannedCode);
}
return (
<SafeAreaView style={backgroundStyle}>
<StatusBar
barStyle={'dark-content'}
backgroundColor={backgroundStyle.backgroundColor}
/>
<ScrollView
contentInsetAdjustmentBehavior="automatic"
style={backgroundStyle}>
<View
style={{backgroundColor: Colors.white,}}>
<ZebraScanner
onScanned={onScanned}
/>
<Text style={styles.highlight}>{scannedText}</Text>
</View>
</ScrollView>
</SafeAreaView>
);
}
export default ScannerScreen;
所以当应用程序检测到设备是zebra时，我已经在app.js中初始化了zebra组件。
{isZebraAvailable ? (<ZebraScanner />) : null}
之后使用上下文来存储扫描数据并在需要时在不同屏幕上使用相同的扫描数据。
以下是来自斑马扫描仪的代码，其中上下文用于发送数据
const {dispatch,} = getStateContext(); const onScannedData = (data: string) => {
dispatch({type: 'scannedData',
scannedData: new String(data),
});};