C# IScanner.Scan方法代码示例

        public CategoriesListViewModel(IProductService service, INavigationService navi, IScanner scanner)
        {
            _service = service;
            _navi = navi;
            _scanner = scanner;

            Items = new NotifyTaskCompletion<List<Product>>(_service.GetProducts());
            Categories = new NotifyTaskCompletion<List<string>>(_service.GetCategories());

            NavigateToCategory = new RelayCommand<string>(async cat =>
            {
                var items = (await _service.GetProductsForCategory(cat))
                    .OrderByDescending(i => i.Rating)
                    .ToList();

                if (items != null && items.Any())
                {
                    var page = App.GetProductsListPage(items, cat);
                    await _navi.PushAsync(page);
                }
                else
                {
                    await _navi.DisplayAlert("Error", "There are no items in the category " + cat);
                }
            });

            _searchCommand = new RelayCommand(Search, () => !string.IsNullOrWhiteSpace(SearchTerm));
            ScanCommand = new RelayCommand(async () =>
            {
                var result = await _scanner.Scan();

                SearchTerm = result.Text;
                Search();
            });
        }

        public CategoriesListViewModel(IProductService service, IAppNavigation navi, IScanner scanner, LogOutCommand logOut)
        {
            _service = service;
            _navi = navi;
            _scanner = scanner;
            _logOut = logOut;

            MessagingCenter.Subscribe<Category>(this, Messages.NavigateTo, NavigateToCategory);

            _searchCommand = new Command(Search, () => !string.IsNullOrWhiteSpace(SearchTerm));
            ScanCommand = new Command(async () =>
            {
                var result = await _scanner.Scan();

                SearchTerm = result.Text;
                Search();
            });

            AboutCommand = new Command(async () => await _navi.ShowAbout());

            Categories = new NotifyTaskCompletion<List<CategoryViewModel>>(GetCategories());
        }

        public AssessmentDetailPage(Opdracht opdracht)
        {
            contactpersoon = DataController.Instance.GetPersons()
            [
                DataController.Instance.GetCompanyPersons().Where(t => t.BedrijfID == opdracht.BedrijfID).ToList().Count > 0 ?
                    DataController.Instance.GetCompanyPersons().Where(t => t.BedrijfID == opdracht.BedrijfID).ToList()[0].PersoonID -1 :
                    0
            ];
            formattedAddress = DataController.Instance.FormattedAddress(opdracht.Adres);
            prestatielijst = DataController.Instance.GetAchievementsFromAssessment (opdracht);

            if (prestatielijst.Count == 0) {
                Prestatie presatie = new Prestatie();
                presatie.Aanvang = DateTime.Now;
                presatie.Duur = 0;
                presatie.OpdrachtID = opdracht.ID;
                DataController.Instance.Insert(presatie);
                SyncController.Instance.SyncNeeded();
                prestatielijst.Add (presatie);
            }

            Title = "Opdracht: " + opdracht.ID;
            Padding = new Thickness (10, 10, 10, 10);
            scanner = DependencyService.Get<IScanner> ();

            BackgroundColor = Color.White;
            generalTermsLayout = new StackLayout ();
            articleLayout = new StackLayout ();
            reportLayout = new StackLayout ();

            lblGeneralTerms = new Label {
                Text = "Algemene info",
                TextColor = Color.Black,
                FontSize = Device.GetNamedSize (NamedSize.Large, typeof(Label)),
                FontAttributes = FontAttributes.Bold
            };

            lblCustommerName = new Label {
                Text = "Naam: "+ DataController.Instance.GetCompanys()[opdracht.BedrijfID].Naam,
                TextColor = Color.Black
            };

            lblDescription = new Label {
                Text = "Omschrijving: "+opdracht.Omschrijving,
                TextColor = Color.Black
            };
            lblAddress = new Label{
                Text = "Adres: " + formattedAddress,
                TextColor = Color.Black
            };

            phoneLayout = new StackLayout {
                Orientation = StackOrientation.Horizontal
            };

            lblPhone = new Label {
                Text = "Telefoon: ",
                TextColor = Color.Black
            };

            lblPhoneNumber = new Label {
                Text = contactpersoon.TelefoonWerk,
                TextColor = Color.Blue
            };

            var tapGestureRecognizer = new TapGestureRecognizer();
            tapGestureRecognizer.Tapped += (s, e) => {
                var dialer = DependencyService.Get<IDialer> ();
                if (dialer != null && contactpersoon.TelefoonWerk != null || contactpersoon.TelefoonWerk!= "") {
                    dialer.Dial (contactpersoon.TelefoonWerk);
                }
            };
            lblPhoneNumber.GestureRecognizers.Add(tapGestureRecognizer);

            phoneLayout.Children.Add (lblPhone);
            phoneLayout.Children.Add (lblPhoneNumber);

            generalTermsLayout.Children.Add (lblGeneralTerms);
            generalTermsLayout.Children.Add (new BoxView{
                Color = Color.FromHex ("ddd"),
                HeightRequest=1,
                VerticalOptions = LayoutOptions.Fill
            });
            generalTermsLayout.Children.Add (lblCustommerName);
            generalTermsLayout.Children.Add (lblDescription);
            generalTermsLayout.Children.Add (lblAddress);
            generalTermsLayout.Children.Add (phoneLayout);
            generalTermsLayout.Children.Add (new BoxView{
                Color = Color.FromHex ("ddd"),
                HeightRequest=1,
                VerticalOptions = LayoutOptions.Fill
            });

            achievementLayout = new StackLayout ();

            lblAchievement = new Label{
                Text = "Prestatie",
                TextColor = Color.Black,
                FontSize = Device.GetNamedSize (NamedSize.Large, typeof(Label)),
                FontAttributes = FontAttributes.Bold
//.........这里部分代码省略.........