我有一个 Ionic 2 应用程序，它使用QuaggaJS Github将相机流式传输到我的视图（Div 容器），如 Snapchat 以扫描 QR 码。在浏览器中，这一切都像一个魅力，但是，当它被构建为 APK 或 IPA 文件时，我得到了错误：
chromium: [INFO:CONSOLE(76955)] "Error: getUserMedia is not defined"
我使用 ADB 和一个虚拟 Android 设备来获取 logcat 输出。 重要信息：是的，我有相机权限！
以防您无法想象我在说什么，这是我的页面视图的屏幕截图：
这是我的打字稿代码：
import { Component, OnInit } from '@angular/core';
import { IonicPage, NavController, NavParams, MenuController } from 'ionic-angular';
import Quagga from 'quagga';
declare var Quagga:any;
@Component({
selector: 'page-scanner',
templateUrl: 'scanner.html',
})
export class Scanner implements OnInit {
constructor(public navCtrl: NavController,
public navParams: NavParams,
public menu: MenuController) {
}
ngOnInit() {
//WARNING:
//Error: Types of property 'lift' are incompatible -> means
//that the used typescript version is too high. Works with: 2.3.4 atm
Quagga.init({
inputStream : {
name : "Live",
type : "LiveStream",
constraints: {
width: window.innerWidth,
height: window.innerHeight,
facingMode: "environment"
},
area: {
top: "0%",
right: "0%",
left: "0%",
bottom: "0%"
},
// Or '#yourElement' (optional)
target: document.querySelector('#scanner')
},
locator: {
patchSize: "medium",
halfSample: true
},
numOfWorkers: (navigator.hardwareConcurrency ? navigator.hardwareConcurrency : 4),
decoder : {
//Change Reader for the right Codes
readers: [ "code_128_reader",
"ean_reader",
"ean_8_reader",
"code_39_reader",
"code_39_vin_reader",
"codabar_reader",
"upc_reader",
"upc_e_reader",
"i2of5_reader" ],
},
locate: true
}, function(err) {
if (err) {
console.log(err);
return
}
console.log("Initialization finished. Ready to start");
Quagga.start();
});
// Make sure, QuaggaJS draws frames an lines around possible
// barcodes on the live stream
Quagga.onProcessed(function(result) {
var drawingCtx = Quagga.canvas.ctx.overlay,
drawingCanvas = Quagga.canvas.dom.overlay;
if (result) {
if (result.boxes) {
drawingCtx.clearRect(0, 0, parseInt(drawingCanvas.getAttribute("width")), parseInt(drawingCanvas.getAttribute("height")));
result.boxes.filter(function (box) {
return box !== result.box;
}).forEach(function (box) {
Quagga.ImageDebug.drawPath(box, {x: 0, y: 1}, drawingCtx, {color: "green", lineWidth: 2});
});
}
if (result.box) {
Quagga.ImageDebug.drawPath(result.box, {x: 0, y: 1}, drawingCtx, {color: "#00F", lineWidth: 2});
}
if (result.codeResult && result.codeResult.code) {
Quagga.ImageDebug.drawPath(result.line, {x: 'x', y: 'y'}, drawingCtx, {color: 'red', lineWidth: 3});
}
}
});
// Once a barcode had been read successfully, stop quagga and
// close the modal after a second to let the user notice where
// the barcode had actually been found.
Quagga.onDetected(function(result) {
if (result.codeResult.code){
// Was passieren soll wenn ein Code gescannt wurde
// $('#scanner_input').val(result.codeResult.code);
}
});
}
ionViewWillLeave(){
Quagga.stop();
}
}