不同的线程在WPF中拥有它

Question

这是UserControl我正在使用的.

this.CardHolderName.Content是label在用户控件的UI中.

public partial class PersonCredential : UserControl
        {
            public PersonCredential()
            {
                InitializeComponent();

                Dispatcher.BeginInvoke( (Action) (() => {
                        SCLib type = new SCLib();
                        type.StartMonitoring();

                        type.CardArrived += (string ATR) => { this.CardHolderName.Content = ATR; };
                    };
               }));

我仍然得到错误," 调用线程无法访问此对象,因为不同的线程拥有它 "即使我正在使用它Dispatcher.BeginInvoke.

Dispatcher使用方式有什么问题吗？}

编辑:我在内容控件中实例化用户控件,代码隐藏是:

public partial class MainWindow : Window
    {
       PersonCredential personCredential {get;set;}

        public MainWindow()
        {

            InitializeComponent();
            var personCredential = new CoffeeShop.PersonCredential();
            //create an instance of user control.
            this.personCredentials.Content = personCredential;
            // assign it to the content control inside the wpf main window
            .. // blah blah
        } 

编辑1:

启动监控代码:

public async void StartMonitoring()
        {

            // Wait for user to press a key

            try
            {
                this.establishContext();

                await Task.Run(new Action(WaitForReaderArrival));
                ////WaitForReaderArrival();

                if (IsReaderArrived())

Answer 1

编辑@DanPuzey 的评论。StartMonitoring已经在另一个线程上进行监视。关键是该CardArrived事件不是从 UI 线程引发的：

public PersonCredential()
{
    InitializeComponent();

    SCLib type = new SCLib();
    type.StartMonitoring();

    type.CardArrived += (string ATR) => { 
        // when card arrives, dispatch back to UI thread
        Dispatcher.BeginInvoke(new Action(() => {
            this.CardHolderName.Content = ATR; 
        }));
    };
}

如果您使用 .NET 4 或更高版本，请Task.Factory.StartNew()使用new Thread().