Why this list is empty when the program run at windows 10 iot core?

Question

There is a List is empty when it run at windows 10 Iot Core.but have value when it run at windows 10. the program is this demo: This demo https://github.com/MicrosoftDocs/windows-topic-specific-samples/archive/uwp-ink-handwriting-reco.zip

And I search the InkRecognizerContainer Class at msdn. https://learn.microsoft.com/en-us/uwp/api/Windows.UI.Input.Inking.InkRecognizerContainer msdn says this class Windows 10 requirements.

    // inkRecognizerContainer is null if a recognition engine is not available.
                if (!(inkRecognizerContainer == null))
                {
                    // Recognize all ink strokes on the ink canvas.
                    //when it run at windows 10.recognitionResults have value.but recognitionResults is empty
                    //when run at windows 10 iot core.
                    IReadOnlyList<InkRecognitionResult> recognitionResults =
                        await inkRecognizerContainer.RecognizeAsync(
                            inkCanvas.InkPresenter.StrokeContainer,
                            InkRecognitionTarget.All);
                    // Process and display the recognition results.
                    if (recognitionResults.Count > 0)
                    {
                        string str = "Recognition result\n";
                        // Iterate through the recognition results.
                        foreach (var result in recognitionResults)
                        {
                            // Get all recognition candidates from each recognition result.
                            IReadOnlyList<string> candidates = result.GetTextCandidates();
                            str += "Candidates: " + candidates.Count.ToString() + "\n";
                            foreach (string candidate in candidates)
                            {
                                str += candidate + " ";
                            }
                        }
                        // Display the recognition candidates.
                        recognitionResult.Text = str;
                        // Clear the ink canvas once recognition is complete.
                        inkCanvas.InkPresenter.StrokeContainer.Clear();
                    }
                    else
                    {
                        recognitionResult.Text = "No recognition results.";
                    }
                }

does the class have not work at windows 10 iot core?or have other reasons?

Answer 1

Windows IoT Core supports InkRecognizerContainer. From build 16299, Windows IoT Core improved ink support. But you need to use a compatible pen digitizer. Multi-modal interactions such as simultaneous pen and touch are also now supported on compatible hardware.Please refer to the Hardware compatibility list.