How to get connected scanner list in UWP

Question

I want to get the connected scanner list(names) and bind the scanner names to combo box, for scan purpose. I am new to UWP, please share any link or code.

I have just installed the NTwain library from NuGet Package.

Answer 1

i want to bind the scanner name to combobox at page load(by creating getScannerName method ) how to do that ?

For your requirement, you could use DeviceWatcher to enumerate all ImageScanner. Then bind the result to the ListView. For more detail you could refer DeviceEnumerationAndPairing official code sample scenario 2.

private void StartWatcher()
    {
        startWatcherButton.IsEnabled = false;
        ResultCollection.Clear();

        // First get the device selector chosen by the UI.
        DeviceSelectorInfo deviceSelectorInfo = (DeviceSelectorInfo)selectorComboBox.SelectedItem;

        if (null == deviceSelectorInfo.Selector)
        {
            // If the a pre-canned device class selector was chosen, call the DeviceClass overload
            deviceWatcher = DeviceInformation.CreateWatcher(deviceSelectorInfo.DeviceClassSelector);
        }
        else if (deviceSelectorInfo.Kind == DeviceInformationKind.Unknown)
        {
            // Use AQS string selector from dynamic call to a device api's GetDeviceSelector call
            // Kind will be determined by the selector
            deviceWatcher = DeviceInformation.CreateWatcher(
                deviceSelectorInfo.Selector, 
                null // don't request additional properties for this sample
                );
        }
        else
        {
            // Kind is specified in the selector info
            deviceWatcher = DeviceInformation.CreateWatcher(
                deviceSelectorInfo.Selector,
                null, // don't request additional properties for this sample
                deviceSelectorInfo.Kind);
        }

        // Hook up handlers for the watcher events before starting the watcher

        handlerAdded = new TypedEventHandler<DeviceWatcher, DeviceInformation>(async (watcher, deviceInfo) =>
        {
            // Since we have the collection databound to a UI element, we need to update the collection on the UI thread.
            await rootPage.Dispatcher.RunAsync(CoreDispatcherPriority.Low, () =>
            {
                ResultCollection.Add(new DeviceInformationDisplay(deviceInfo));

                rootPage.NotifyUser(
                    String.Format("{0} devices found.", ResultCollection.Count),
                    NotifyType.StatusMessage);
            });
        });
        deviceWatcher.Added += handlerAdded;

        handlerUpdated = new TypedEventHandler<DeviceWatcher, DeviceInformationUpdate>(async (watcher, deviceInfoUpdate) =>
        {
            // Since we have the collection databound to a UI element, we need to update the collection on the UI thread.
            await rootPage.Dispatcher.RunAsync(CoreDispatcherPriority.Low, () =>
            {
                // Find the corresponding updated DeviceInformation in the collection and pass the update object
                // to the Update method of the existing DeviceInformation. This automatically updates the object
                // for us.
                foreach (DeviceInformationDisplay deviceInfoDisp in ResultCollection)
                {
                    if (deviceInfoDisp.Id == deviceInfoUpdate.Id)
                    {
                        deviceInfoDisp.Update(deviceInfoUpdate);
                        break;
                    }
                }
            });
        });
        deviceWatcher.Updated += handlerUpdated;

        handlerRemoved = new TypedEventHandler<DeviceWatcher, DeviceInformationUpdate>(async (watcher, deviceInfoUpdate) =>
        {
            // Since we have the collection databound to a UI element, we need to update the collection on the UI thread.
            await rootPage.Dispatcher.RunAsync(CoreDispatcherPriority.Low, () =>
            {
                // Find the corresponding DeviceInformation in the collection and remove it
                foreach (DeviceInformationDisplay deviceInfoDisp in ResultCollection)
                {
                    if (deviceInfoDisp.Id == deviceInfoUpdate.Id)
                    {
                        ResultCollection.Remove(deviceInfoDisp);
                        break;
                    }
                }

                rootPage.NotifyUser(
                    String.Format("{0} devices found.", ResultCollection.Count), 
                    NotifyType.StatusMessage);
            });
        });
        deviceWatcher.Removed += handlerRemoved;

        handlerEnumCompleted = new TypedEventHandler<DeviceWatcher, Object>(async (watcher, obj) =>
        {
            await rootPage.Dispatcher.RunAsync(CoreDispatcherPriority.Low, () =>
            {
                rootPage.NotifyUser(
                    String.Format("{0} devices found. Enumeration completed. Watching for updates...", ResultCollection.Count),
                    NotifyType.StatusMessage);
            });
        });
        deviceWatcher.EnumerationCompleted += handlerEnumCompleted;

        handlerStopped = new TypedEventHandler<DeviceWatcher, Object>(async (watcher, obj) =>
        {
            await rootPage.Dispatcher.RunAsync(CoreDispatcherPriority.Low, () =>
            {
                rootPage.NotifyUser(
                    String.Format("{0} devices found. Watcher {1}.", 
                        ResultCollection.Count,
                        DeviceWatcherStatus.Aborted == watcher.Status ? "aborted" : "stopped"),
                    NotifyType.StatusMessage);
            });
        });
        deviceWatcher.Stopped += handlerStopped;

        rootPage.NotifyUser("Starting Watcher...", NotifyType.StatusMessage);
        deviceWatcher.Start();
        stopWatcherButton.IsEnabled = true;
    }