我刚开始使用NativeScript，需要能够读取QR码。我下载了NativeScript的BarcodeScanner插件（我使用的是JavaScript，而不是TypeScript），我无法弄清楚如何使用它。我仍然找不到任何有用或信息丰富的教程。有没有人知道任何好的教程或任何人都可以告诉我如何使用它（举个例子）。提前谢谢！
答案 0 :(得分：2)
您可以查看插件仓库demo project，其中显示了如何使用nativescript-barcodescanner。关于这一点，该项目已经在TypeScript上编写，但是您可以克隆repo并构建项目，然后您可以查看已编译的JavaScript文件。为了您的帮助，我附上了插件演示中的JavaScript代码。
主page.xml
<Page xmlns="http://www.nativescript.org/tns.xsd" xmlns:Barcode="nativescript-barcodescanner" loaded="pageLoaded">
<TabView class="tab-view">
<TabView.items>
<TabViewItem title="About">
<TabViewItem.view>
<StackLayout class="tab-content">
<Image margin="10" src="~/res/telerik-logo.png" />
<Label class="h3" text="BarcodeScanner plugin demo" />
<Label class="body" text="The BarcodeScanner plugin supports extracting data from a large range of barcodes, including QR codes. Your app will receive the type of barcode and the encode value." textWrap="true"/>
</StackLayout>
</TabViewItem.view>
</TabViewItem>
<TabViewItem title="Demo">
<TabViewItem.view>
<ScrollView>
<StackLayout class="tab-content">
<Label class="h3" text="Checking availability" />
<Label class="body" text="It can never hurt to check upfront if a device is capable of scanning a barcode." textWrap="true"/>
<Button class="btn btn-primary btn-rounded-sm" text="available?" tap="{{ doCheckAvailable }}" />
<Label class="h3" text="Camera permission" />
<Label class="body" text="Android 6+ and iOS 10+ require runtime user consent. The plugin handles it automatically but you can do it manually as well." textWrap="true"/>
<Button class="btn btn-outline btn-rounded-sm" text="has permission?" tap="{{ doCheckHasCameraPermission }}" />
<Button class="btn btn-primary btn-rounded-sm" text="request permission" tap="{{ doRequestCameraPermission }}" />
<!--iOS>
<ContentView height="240" width="240">
<Barcode:BarcodeScannerView></Barcode:BarcodeScannerView>
</ContentView>
</iOS-->
<Label class="h3" text="Scanning (QR & EAN-13)" />
<Label class="body" text="You can use the volume buttons to toggle the torch." textWrap="true"/>
<Button class="btn btn-primary btn-rounded-sm" text="back camera, with flip" tap="{{ doScanWithBackCamera }}" />
<Button class="btn btn-primary btn-rounded-sm" text="front camera, no flip" tap="{{ doScanWithFrontCamera }}" />
<iOS>
<Button class="btn btn-primary btn-rounded-sm" text="back camera, with torch" tap="{{ doScanWithTorch }}" />
</iOS>
<Label class="h3" text="Continuous scanning (see console)" />
<Button class="btn btn-primary btn-rounded-sm" text="stop after 3 results" tap="{{ doContinuousScanMax3 }}" />
<Button class="btn btn-primary btn-rounded-sm" text="scan till you drop" tap="{{ doContinuousScan }}" />
<Android>
<Label class="h3" text="Orientation lock" />
<Button class="btn btn-primary btn-rounded-sm" text="back camera, portrait" tap="{{ doScanPortrait }}" />
<Button class="btn btn-primary btn-rounded-sm" text="back camera, landscape" tap="{{ doScanLandscape }}" />
</Android>
</StackLayout>
</ScrollView>
</TabViewItem.view>
</TabViewItem>
</TabView.items>
</TabView>
</Page>
主page.js
var main_view_model_1 = require("./main-view-model");
// Event handler for Page "loaded" event attached in main-page.xml
function pageLoaded(args) {
// Get the event sender
var page = args.object;
page.bindingContext = new main_view_model_1.HelloWorldModel();
}
exports.pageLoaded = pageLoaded;
主视-model.js
var observable_1 = require("data/observable");
var dialogs_1 = require("ui/dialogs");
var nativescript_barcodescanner_1 = require("nativescript-barcodescanner");
var HelloWorldModel = (function (_super) {
__extends(HelloWorldModel, _super);
function HelloWorldModel() {
_super.call(this);
this.barcodeScanner = new nativescript_barcodescanner_1.BarcodeScanner();
}
HelloWorldModel.prototype.doCheckAvailable = function () {
this.barcodeScanner.available().then(function (avail) {
dialogs_1.alert({
title: "Scanning available?",
message: avail ? "YES" : "NO",
okButtonText: "OK"
});
}, function (err) {
dialogs_1.alert(err);
});
};
HelloWorldModel.prototype.doCheckHasCameraPermission = function () {
this.barcodeScanner.hasCameraPermission().then(function (permitted) {
dialogs_1.alert({
title: "Has Camera permission?",
message: permitted ? "YES" : "NO",
okButtonText: "OK"
});
}, function (err) {
dialogs_1.alert(err);
});
};
HelloWorldModel.prototype.doRequestCameraPermission = function () {
this.barcodeScanner.requestCameraPermission().then(function () {
console.log("Camera permission requested");
});
};
;
HelloWorldModel.prototype.doScanWithBackCamera = function () {
this.scan(false, true);
};
;
HelloWorldModel.prototype.doScanWithFrontCamera = function () {
this.scan(true, false);
};
;
HelloWorldModel.prototype.doScanWithTorch = function () {
this.scan(false, true, true, "portrait");
};
;
HelloWorldModel.prototype.doScanPortrait = function () {
this.scan(false, true, false, "portrait");
};
;
HelloWorldModel.prototype.doScanLandscape = function () {
this.scan(false, true, false, "landscape");
};
;
HelloWorldModel.prototype.doContinuousScan = function () {
this.barcodeScanner.scan({
continuousScanCallback: function (result) {
console.log(result.format + ": " + result.text);
}
});
};
;
HelloWorldModel.prototype.doContinuousScanMax3 = function () {
var count = 0;
console.log("-- in doContinuousScanMax3, count: " + count);
var self = this;
this.barcodeScanner.scan({
reportDuplicates: false,
continuousScanCallback: function (result) {
count++;
console.log(result.format + ": " + result.text + " (count: " + count + ")");
if (count === 3) {
// funilly this is required on Android to reset the counter for a second run
count = 0;
self.barcodeScanner.stop();
setTimeout(function () {
dialogs_1.alert({
title: "Scanned 3 codes",
message: "Check the log for the results",
okButtonText: "Sweet!"
});
}, 1000);
}
}
});
};
;
HelloWorldModel.prototype.scan = function (front, flip, torch, orientation) {
this.barcodeScanner.scan({
formats: "QR_CODE, EAN_13",
cancelLabel: "EXIT. Also, try the volume buttons!",
message: "Use the volume buttons for extra light",
preferFrontCamera: front,
showFlipCameraButton: flip,
showTorchButton: torch,
orientation: orientation,
openSettingsIfPermissionWasPreviouslyDenied: true // On iOS you can send the user to the settings app if access was previously denied
}).then(function (result) {
// Note that this Promise is never invoked when a 'continuousScanCallback' function is provided
setTimeout(function () {
dialogs_1.alert({
title: "Scan result",
message: "Format: " + result.format + ",\nValue: " + result.text,
okButtonText: "OK"
});
}, 500);
}, function (errorMessage) {
console.log("No scan. " + errorMessage);
});
};
;
return HelloWorldModel;
}(observable_1.Observable));
exports.HelloWorldModel = HelloWorldModel;
希望这有帮助