c# - 为什么关闭在单元测试中创建的窗口会引发 InvalidComObjectException？

Question

当使用 MSTest 进行单元测试时，我创建了一个 WPF 窗口。当此窗口关闭时，Visual Studio 显示 InvalidComObjectException:

COM object that has been separated from its underlying RCW cannot be used.

它在[TestMethod] 退出后 引发，并且堆栈仅包含外部代码(无InnerException)。这是我的:

StackTrace:
       at System.Windows.Input.TextServicesContext.StopTransitoryExtension()
       at System.Windows.Input.TextServicesContext.Uninitialize(Boolean appDomainShutdown)
       at System.Windows.Input.TextServicesContext.TextServicesContextShutDownListener.OnShutDown(Object target, Object sender, EventArgs e)
       at MS.Internal.ShutDownListener.HandleShutDown(Object sender, EventArgs e)

DeclaringType:
    {Name = "TextServicesContext" FullName = "System.Windows.Input.TextServicesContext"}

    Assembly:
        {PresentationCore, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35}

这是创建窗口的代码:

var myWindow = new SomeWindow(errors);
myWindow.ShowDialog();

该窗口包含两个 ListView，其中包含一些文本元素和复选框

Answer 1

我前段时间偶然发现了这个。如果我没记错的话，那是因为在测试之间您的 AppDomain 的默认 Dispatcher 没有正确清理和重新初始化。

为了解决这个问题，我创建了一个 DomainNeedsDispatcherCleanup 属性类，负责 Dispatcher 的正确设置和拆卸。我会在找到它后立即将其包含在这里，但请注意我使用的是 XUnit，而不是 MSTest。

编辑:刚找到它。给你:

using System;
using System.Reflection;
using System.Runtime.InteropServices;
using System.Windows;
using System.Windows.Interop;
using System.Windows.Threading;
using Xunit;

namespace Boost.Utils.Testing.XUnit.WPF
{
    /// <summary>helful if you stumble upon 'object disconnected from RCW' ComException *after* the test suite finishes,
    /// or if you are unable to start the test because the VS test runner tells you 'Unable to start more than one local run'
    /// even if all tests seem to have finished</summary>
    /// <remarks>only to be used with xUnit STA worker threads</remarks>
    [AttributeUsage(AttributeTargets.Method)]
    public class DomainNeedsDispatcherCleanupAttribute : BeforeAfterTestAttribute
    {
        public override void After(MethodInfo methodUnderTest)
        {
            base.After(methodUnderTest);

            Dispatcher.CurrentDispatcher.InvokeShutdown();
        }
    }
}

哈哈.. 所以，如您所见，修复是微不足道的。我不记得了。当然，您只需要在拆解中 InvokeShutdown 即可修复它。