在线程之间移动 DependencyObject

发布于 2024-12-13 01:16:05 字数 757 浏览 1 评论 0原文

我在 WPF 应用程序的单独线程中执行冗长的操作（连接测试、远程数据库表验证等）。在测试过程中，我为用户收集有关哪些测试通过、哪些测试未通过的信息。这些信息存储为我自己设计的对象的 List：

public class StatusItem : DependencyObject
{
    public string Text { get... set... }
    public Status Status { get... set... }
    public string Details { get... set... }
}

所有这些属性都是其相应 DependencyProperty 的前面。操作完成后（在单独的线程中），我将收集的信息“状态”设置为“窗口”上的私有字段。我得到一个：

InvalidOperationException:
The calling thread cannot access this object because a different thread owns it.

有没有办法让我将 status （List）从 TestThread 传输到我的主线程，而不必求助于委托和 调度程序调用？

PS：我可以执行 Invoke，但我宁愿避免创建 CopyStatusItemsDelegate 委托。

原文

I perform a lengthy operation (connection test, validation of remote DB tables, etc.) in a separate thread in a WPF app. During the testing, I collect information for the user about which tests were passed and which weren't. The information is stored as a List<T> of objects of my own design:

public class StatusItem : DependencyObject
{
    public string Text { get... set... }
    public Status Status { get... set... }
    public string Details { get... set... }
}

All these properties are a front for their corresponding DependencyProperty. When the operation is completed (in the separate thread), I set the collected info, status, to a private field on my Window. I get a:

InvalidOperationException:
The calling thread cannot access this object because a different thread owns it.

Is there a way for me to transfer status (a List<StatusItem>) from TestThread to my main thread without having to resort to delegates and Dispatcher invokes?

PS: I could do Invoke, but I'd rather avoid having to create a CopyStatusItemsDelegate delegate.

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小镇女孩 2024-12-20 01:16:05

我认为没有一个好的解决方案。上述情况就是为什么我不从 DependencyObject 派生 Item-ViewModels 而是实现 INotifiyPropertyChanged 的原因。

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口干舌燥 2024-12-20 01:16:05

关于 DependencyObject 来自 msdn：

该对象只能从它所在的线程访问
创建的。尝试从其他线程访问它会抛出
无效操作异常。 Invoke 或 BeginInvoke 提供支持
将工作编组到正确的线程。

如果您的情况必须有 DependencyObject，请使用 Invoke。否则，我建议您使用 INotifyPropertyChanged 接口实现。

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自控 2024-12-20 01:16:05

如果您完全信任，您可以使用以下技巧：

public static class DispatcherExtenstions {
    public static void SetAccess(this DispatcherObject d) {
        if(d.CheckAccess()) return;
        Dispatcher dispatcher = d.Dispatcher;
        FieldInfo dispatcherThreadField = typeof(Dispatcher).GetField("_dispatcherThread", BindingFlags.Instance | BindingFlags.NonPublic);
        dispatcherThreadField.SetValue(dispatcher, Thread.CurrentThread);
}
}

示例：

public partial class MainWindow : Window {
    Button b;
    public MainWindow() {
        InitializeComponent();
        Thread t = new Thread(CreateButton);
        t.SetApartmentState(ApartmentState.STA);
        t.Start();
    }
    void CreateButton() {
        b = new Button() { Padding = new Thickness(20.0) };
        b.Content = new Button { Content = "Button" };
        Dispatcher.BeginInvoke((Action)ShowButton);
    }
    void ShowButton() {
        b.SetAccess();
        Content = b;
    }
}

You can use the following hack if you have full trust:

public static class DispatcherExtenstions {
    public static void SetAccess(this DispatcherObject d) {
        if(d.CheckAccess()) return;
        Dispatcher dispatcher = d.Dispatcher;
        FieldInfo dispatcherThreadField = typeof(Dispatcher).GetField("_dispatcherThread", BindingFlags.Instance | BindingFlags.NonPublic);
        dispatcherThreadField.SetValue(dispatcher, Thread.CurrentThread);
}
}

Sample:

public partial class MainWindow : Window {
    Button b;
    public MainWindow() {
        InitializeComponent();
        Thread t = new Thread(CreateButton);
        t.SetApartmentState(ApartmentState.STA);
        t.Start();
    }
    void CreateButton() {
        b = new Button() { Padding = new Thickness(20.0) };
        b.Content = new Button { Content = "Button" };
        Dispatcher.BeginInvoke((Action)ShowButton);
    }
    void ShowButton() {
        b.SetAccess();
        Content = b;
    }
}

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