问在带有WPF的MVVM中，如何对ViewModel和视图之间的链接进行单元测试

EN

[TestMethod]
public void CheckWpfBindingsAreValid()
{
    // instansiate the xaml view and set DataContext
    var yourView = new YourView(); 
    yourView.DataContext = YourViewModel;

    FindBindingsRecursively(yourView,
            delegate(FrameworkElement element, Binding binding, DependencyProperty dp)
            {
                var type = yourView.DataContext.GetType();

                // check that each part of binding valid via reflection
                foreach (string prop in binding.Path.Path.Split('.'))
                {
                    PropertyInfo info = type.GetProperty(prop);
                    Assert.IsNotNull(info);
                    type = info.PropertyType;
                }
    });
}

private delegate void FoundBindingCallbackDelegate(FrameworkElement element, Binding binding, DependencyProperty dp);

private void FindBindingsRecursively(DependencyObject element, FoundBindingCallbackDelegate callbackDelegate)
{
    // See if we should display the errors on this element
    MemberInfo[] members = element.GetType().GetMembers(BindingFlags.Static |
                BindingFlags.Public |
                BindingFlags.FlattenHierarchy);

    foreach (MemberInfo member in members)
    {
        DependencyProperty dp = null;

        // Check to see if the field or property we were given is a dependency property
        if (member.MemberType == MemberTypes.Field)
        {
            FieldInfo field = (FieldInfo)member;
            if (typeof(DependencyProperty).IsAssignableFrom(field.FieldType))
            {
                dp = (DependencyProperty)field.GetValue(element);
            }
        }
        else if (member.MemberType == MemberTypes.Property)
        {
            PropertyInfo prop = (PropertyInfo)member;
            if (typeof(DependencyProperty).IsAssignableFrom(prop.PropertyType))
            {
                dp = (DependencyProperty)prop.GetValue(element, null);
            }
        }

        if (dp != null)
        {
            // Awesome, we have a dependency property. does it have a binding? If yes, is it bound to the property we're interested in?
            Binding bb = BindingOperations.GetBinding(element, dp);
            if (bb != null)
            {
                // This element has a DependencyProperty that we know of that is bound to the property we're interested in. 
                // Now we just tell the callback and the caller will handle it.
                if (element is FrameworkElement)
                {
                    callbackDelegate((FrameworkElement)element, bb, dp);
                }
            }
        }
    }

    // Now, recurse through any child elements
    if (element is FrameworkElement || element is FrameworkContentElement)
    {
        foreach (object childElement in LogicalTreeHelper.GetChildren(element))
        {
            if (childElement is DependencyObject)
            {
                FindBindingsRecursively((DependencyObject)childElement, callbackDelegate);
            }
        }
    }
}

abstract class ViewModelBase
{
    [Conditional("DEBUG")]
    public void VerifyPropertyName(string propertyName)
    {
        // Verify that the property name matches a real,  
        // public, instance property on this object.
        if (TypeDescriptor.GetProperties(this)[propertyName] == null)
        {
            if (this.ThrowOnInvalidPropertyName)
                throw new ArgumentException(propertyName);

            string msg = "Invalid property name: " + propertyName;
            Debug.Fail(msg);
        }
    }

    protected void OnPropertyChanged(string propertyName)
    {
        VerifyPropertyName(propertyName);

        PropertyChangedEventHandler handler = this.PropertyChanged;
        if (handler != null)
        {
            var e = new PropertyChangedEventArgs(propertyName);
            handler(this, e);
        }
    }
}

 [Test]
    public void TestBindings()
    {
        TestBinding<IndividualSolutionViewModel, string>(x => x.Name, "Name", TextBlock.TextProperty);
    }

    private void TestBinding<TViewModel,TResult>(Expression<Func<TViewModel, TResult>> property, string elementName, 
        DependencyProperty dependencyProperty)
    {
        string memberName = ExpressionHelper.GetPropertyName(property); // f.ex v => v.Name will return Name
        TestBinding(memberName, elementName, dependencyProperty);

    }

    private void TestBinding(string memberName, string elementInControlName, DependencyProperty dependencyProperty)
    {
        //object viewModel = new IndividualSolutionViewModel();
        var view = new IndividualSolutionView();

        //Assert.That(view.DataContext, Is.EqualTo(viewModel));

        var element = view.FindName(elementInControlName);
        Assert.That(element, Is.Not.Null, string.Format("Unable to find the element {0} in view {1}", elementInControlName, view.Name));
        Assert.That(element, Is.InstanceOf(typeof(DependencyObject)));

        var binding = BindingOperations.GetBinding(element as DependencyObject, dependencyProperty);
        Assert.That(binding, Is.Not.Null, string.Format("Could not find a binding for the control {0}", elementInControlName));

        Assert.That(binding.Path.Path, Is.EqualTo(memberName));
    }

<configSections>
    <sectionGroup name="NUnit">
        <section type="System.Configuration.NameValueSectionHandler"
                 name="TestRunner"></section>
    </sectionGroup>
</configSections>
<NUnit>
    <TestRunner>
        <add value="STA" key="ApartmentState"></add>
    </TestRunner>
</NUnit>