错误:未定义的不是对象(计算'$cordovaBarcodeScanner.scan')

cordova plugin add cordova-plugin-barcodescanner

angular.module('myApp', ['ngCordova'])
  .controller('MyController', function($scope, $cordovaBarcodeScanner) {
    $scope.scanBarcode = function() {
      $cordovaBarcodeScanner.scan().then(function(result) {
        // 成功扫描
        console.log('Barcode Format: ' + result.format);
        console.log('Cancelled: ' + result.cancelled);
      }, function(error) {
        // 扫描失败
        console.error('Error scanning barcode: ', error);
      });
    };
  });

angular.module('myApp', ['ngCordova']);

document.addEventListener('deviceready', function() {
  // 在这里调用 $cordovaBarcodeScanner.scan()
}, false);

angular.module('myApp', ['ngCordova'])
  .controller('MyController', function($scope, $cordovaBarcodeScanner) {
    document.addEventListener('deviceready', function() {
      $scope.scanBarcode = function() {
        $cordovaBarcodeScanner.scan().then(function(result) {
          console.log('Barcode Format: ' + result.format);
          console.log('Cancelled: ' + result.cancelled);
        }, function(error) {
          console.error('Error scanning barcode: ', error);
        });
      };
    }, false);
  });