Win IOT 上的 NFC-reader：Pin ' 当前以不兼容的共享模式打开

Question

我正在 Rasperry PI 3 上基于 Windows 10 IoT 运行进行 NFC reader 项目。

我使用在此处找到的库 Mfrc522lib.cs：。我使用异步任务来等待卡片。它第一次扫描完美，但当我再次开始任务时（用于带按钮的测试 puprose）。我明白了：

Pin ' is currently opened in an incompatible sharing mode. Make sure this pin is not already in use by this application or another Application

有什么想法吗？

public MainPage()
{
    this.InitializeComponent();
    startNFC();
}

public void startNFC()
{
    var read = ReadNFCAsync();

    Windows.ApplicationModel.Core.CoreApplication.MainView.CoreWindow.Dispatcher.RunAsync(CoreDispatcherPriority.Normal,
        () =>
        {
            // Your UI update code goes here!
            this.serial.Text = "Klar for å lese kortet ditt";
            this.statusline.Fill = new SolidColorBrush(Colors.Green);
        });
    read.ContinueWith(prev => {
        Windows.ApplicationModel.Core.CoreApplication.MainView.CoreWindow.Dispatcher.RunAsync(CoreDispatcherPriority.Normal,
            () =>
            {
                // Your UI update code goes here!
                this.serial.Text = prev.Result.ToString();
                this.statusline.Fill = new SolidColorBrush(Colors.Orange);
            });
    });
}

public static async Task<String> ReadNFCAsync()
{
    await Task.Delay(1000); 
    var mfrc  = new Mfrc522();

    await mfrc.InitIO();

    while (true)
    {
        if (mfrc.IsTagPresent())
        {

            var uid = mfrc.ReadUid();
            var serial= uid.ToString();

            mfrc.HaltTag();
            return serial;

        }
    }
}

private async void Button_Click(object sender, RoutedEventArgs e)
{
    startNFC();
}

Answer 1

这个问题是由于正在使用初始化 GPIO 引脚。因为每次点击按钮都会执行下面一行：

await mfrc.InitIO();

要解决此问题，您可以像这样编辑代码：

    private Mfrc522 mfrc = new Mfrc522();

    public static bool IsGpioInitialized = false;

    public async Task ReadNFCAsync()
    {
        if (!IsGpioInitialized)
        {
            await mfrc.InitIO();
            IsGpioInitialized = true;
        }
    }

Win IOT 上的 NFC-reader：Pin ' 当前以不兼容的共享模式打开

NFC-reader on Win IOT: Pin ' is currently opened in an incompatible sharing mode

c#

windowsiot