ionic-framework - 使用 BarcodeScanner 时,我的 ionic 应用程序出现以下错误
问题描述
我正在开发一个应用程序来读取我正在使用 BarcodeScanner 的代码,但是当我在我的设备上执行该应用程序时,我收到以下错误
**
**使用 ionic DevApp 错误运行时错误对象(_WEBPACK_IMPORTED_MODULE_1_ionic_native_core_["cordova"]) 在我的 iphone 6 上运行它时出错,它不是函数。(在 'Object(_WEBPACK_IMPORTED_MODULE_1_ionic_native_core_["cordova"])(this, "scan", {"callbackOrder":"reverse"}, arguments)', 'Object(_WEBPACK_IMPORTED_MODULE_1_ionic_native_core_["cordova"])' 是 Object 的一个实例)
在 ionic serve 中执行时显示的错误,ERROR TypeError: Object(...) is not a function at BarcodeScanner.scan (index.js:31) at MenuPage.webpackJsonp.101.MenuPage.scanQR (menu.ts: 53) 在 Object.eval [as handleEvent] (MenuPage.html:17) at handleEvent (core.js:13589) at callWithDebugContext (core.js:15098) at Object.debugHandleEvent [as handleEvent] (core.js:14685)在 HTMLButtonElement 的 core.js:10629 的 dispatchEvent (core.js:10004)。(platform-browser.js:2628) 在 t.invokeTask (polyfills.js:3) **
一开始我遇到错误,我的 app-module.ts 无法识别 BarcodeScanner,因为在提供程序中调用它时,TS2322:类型“BarcodeScannerOriginal”不可分配给类型“Provider”。类型“BarcodeScannerOriginal”不可分配给类型“FactoryProvider”。“BarcodeScannerOriginal”类型中缺少属性“provide”
** 菜单.html
<ion-header class="toolbar">
<ion-navbar>
<ion-title>Scan</ion-title>
</ion-navbar>
</ion-header>
<ion-content padding class="Scan">
<div class="row">
<div class="col">
<h2>Scan your QR Code Here</h2>
</div>
<div class="col">
<h3>{{eventTitle}}</h3>
</div>
</div>
<button ion-button block color="secondary" class="Scan-button" (click)="scanQR()" [disabled]="loading">{{buttonText}}</button>
</ion-content>
菜单.ts
import { Component } from '@angular/core';
import {Platform} from "ionic-angular";
import { IonicPage, NavController, NavParams } from 'ionic-angular';
import { SplashScreen } from '@ionic-native/splash-screen';
import { StatusBar } from '@ionic-native/status-bar';
import { ToastController } from 'ionic-angular';
import { BarcodeScanner, BarcodeScannerOptions } from '@ionic-native/barcode-scanner/ngx';
/**
* Generated class for the MenuPage page.
*
* See https://ionicframework.com/docs/components/#navigation for more info on
* Ionic pages and navigation.
*/
@IonicPage()
@Component({
selector: 'page-menu',
templateUrl: 'menu.html',
})
export class MenuPage {
public scannedText: string;
public buttonText: string;
public loading: boolean;
private eventId: number;
public eventTitle: string;
num: string;
// @ts-ignore
constructor(private _nav: NavController,
private _navParams: NavParams,
private _barcodeScanner: BarcodeScanner) {
}
ionViewDidLoad() {
this.eventId = this._navParams.get('eventId');
this.eventTitle = this._navParams.get('eventTitle');
this.buttonText = "Scan";
this.loading = false;
}
public scanQR() {
this.buttonText = "Loading..";
this.loading = true;
this._barcodeScanner.scan().then((barcodeData) => {
if (barcodeData.cancelled) {
console.log("User cancelled the action!");
this.buttonText = "Scan";
this.loading = false;
return false;
}
console.log("Scanned successfully!");
console.log(barcodeData);
this.goToResult(barcodeData);
}, (err) => {
console.log(err);
});
}
private goToResult(barcodeData) {
this._nav.push(ScanResultPage, {
scannedText: barcodeData.text
});
}
}
应用模块.ts
import { BrowserModule } from '@angular/platform-browser';
import { ErrorHandler, NgModule } from '@angular/core';
import { IonicApp, IonicErrorHandler, IonicModule } from 'ionic-angular';
import { SplashScreen } from '@ionic-native/splash-screen';
import { StatusBar } from '@ionic-native/status-bar';
import { MyApp } from './app.component';
import { HomePage } from '../pages/home/home';
import {MenuPage} from "../pages/menu/menu";
import { BarcodeScanner } from '@ionic-native/barcode-scanner/ngx';
import { HttpClientModule } from '@angular/common/http';
import { FormsModule } from '@angular/forms';
import {HttpModule} from "@angular/http";
// @ts-ignore
@NgModule({
declarations: [
MyApp,
HomePage,
MenuPage
],
imports: [
BrowserModule, HttpClientModule,
IonicModule.forRoot(MyApp),
HttpModule
],
bootstrap: [IonicApp],
entryComponents: [
MyApp,
HomePage,
MenuPage
],
providers: [
StatusBar,
SplashScreen,
BarcodeScanner,
{provide: ErrorHandler, useClass: IonicErrorHandler}
]
})
export class AppModule {}
解决方案
我的猜测是您使用的是 Ionic 3,但您使用的是 Ionic 4 支持的本机插件版本。
解决方案
卸载cordova和离子原生插件
$ionic cordova plugin remove phonegap-plugin-barcodescanner
$npm uninstall @ionic-native/barcode-scanner
安装版本4。
$ ionic cordova plugin add phonegap-plugin-barcodescanner
$ npm install --save @ionic-native/barcode-scanner@4
并且不要在导入结束时附加ngx 。
import { BarcodeScanner } from '@ionic-native/barcode-scanner';
笔记
如果您使用的是 Ionic 3,请尝试遵循 Ionic v3 指南而不是最新指南
Ionic v3 指南:https ://ionicframework.com/docs/v3/native/barcode-scanner/
如需完整解释,您可以在此处找到我的其他答案:https ://stackoverflow.com/a/54474247/6617276
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