Question

对于我的一些单元测试，我必须调用需要Window作为参数的方法。不幸的是我无法传递null，因为该方法使用窗口作为参考来更新状态栏，在那里我显示实际应用程序中实际加载的内容。

所以我试着在单元测试中调用构造函数：

MainWindow window = new MainWindow();

但是这会导致MainWindow构造函数的InitializeComponent方法出现以下错误：

System.Windows.Markup.XamlParseException occurred
  Message='Provide value on 'System.Windows.Baml2006.TypeConverterMarkupExtension' threw an exception.' Line number '9' and line position '42'.
  Source=PresentationFramework
  LineNumber=9
  LinePosition=42
  StackTrace:
       at System.Windows.Markup.XamlReader.RewrapException(Exception e, IXamlLineInfo lineInfo, Uri baseUri)
  InnerException: System.IO.IOException
       Message=Assembly.GetEntryAssembly() returns null. Set the Application.ResourceAssembly property or use the pack://application:,,,/assemblyname;component/ syntax to specify the assembly to load the resource from.
       Source=PresentationFramework
       StackTrace:
            at MS.Internal.AppModel.ResourceContainer.GetResourceManagerWrapper(Uri uri, String& partName, Boolean& isContentFile)
            at MS.Internal.AppModel.ResourceContainer.GetPartCore(Uri uri)
            at System.IO.Packaging.Package.GetPartHelper(Uri partUri)
            at System.IO.Packaging.Package.GetPart(Uri partUri)
            at System.IO.Packaging.PackWebResponse.CachedResponse.GetResponseStream()
            at System.IO.Packaging.PackWebResponse.GetResponseStream()
            at System.IO.Packaging.PackWebResponse.get_ContentType()
            at System.Windows.Media.Imaging.BitmapDecoder.SetupDecoderFromUriOrStream(Uri uri, Stream stream, BitmapCacheOption cacheOption, Guid& clsId, Boolean& isOriginalWritable, Stream& uriStream, UnmanagedMemoryStream& unmanagedMemoryStream, SafeFileHandle& safeFilehandle)
            at System.Windows.Media.Imaging.BitmapDecoder.CreateFromUriOrStream(Uri baseUri, Uri uri, Stream stream, BitmapCreateOptions createOptions, BitmapCacheOption cacheOption, RequestCachePolicy uriCachePolicy, Boolean insertInDecoderCache)
            at System.Windows.Media.Imaging.BitmapFrame.CreateFromUriOrStream(Uri baseUri, Uri uri, Stream stream, BitmapCreateOptions createOptions, BitmapCacheOption cacheOption, RequestCachePolicy uriCachePolicy)
            at System.Windows.Media.ImageSourceConverter.ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, Object value)
            at System.Windows.Baml2006.TypeConverterMarkupExtension.ProvideValue(IServiceProvider serviceProvider)
            at MS.Internal.Xaml.Runtime.ClrObjectRuntime.CallProvideValue(MarkupExtension me, IServiceProvider serviceProvider)
       InnerException:

所以我的问题是，如何在单元测试中实例化或模拟窗口？

Answer 1

尝试以下方法：

if(Application.ResourceAssembly == null)
    Application.ResourceAssembly = typeof(MainWindow).Assembly;
var window = new MainWindow();

Answer 2

简短的回答是你不应该。单元测试未在UI 上完成。

应该在逻辑代码上运行单元测试，这就是MVC和MVVM之类的模式可以提供帮助的地方。应使用CodedUI等工具测试UI。

如果你的逻辑依赖于UI，那么你做错了。

如何以编程方式实例化或模拟Window？

2 个答案: