I've started writing my first WPF/MVVM and as many other people have found, dealing with navigation between views is rather confusing.
I've been searching for a while and most of the topics either recommend using MVVM Light/PRISM, or come up with solutions similar to one from here.
I'm trying to approach an MVVM navigation mechanism in which I can switch directly from one view to another view (without using the datatemplate switch from the parent window). Let's say, I have an app with a main window loading dynamic content from different usercontrols (views).
The MainWindowViewModel would have a CurrentV property pointed to, say, UserListV and a CurrentVM property pointed to UserListVM. Now that I select one user from the list and click on the View button to view that user details in another screen of the same window. This should allow me to switch to the UserV with UserVM as data context.
I wonder how should I, while being on UserListVM, make a call to MainWindowViewModel to update the CurrentV and CurrentVM values, and switching the window to the UserV accordingly?
Any suggestion of a better idea is more than welcome!
Thank you very much!
I use a messaging service for communication between ViewModels, while still keeping them decoupled. If you are using MVVMLight, it comes with one. I prefer not to use an MVVM framework, and write my own messaging service. Here is an example of one from a recent project:
public class MessageService : IMessageService
{
private List<IMessageSubscription> subscribers; //list of subscription objects registered
public MessageService()
{
subscribers = new List<IMessageSubscription>();
}
public void Subscribe<T>(string message, Action<T> action)
{
subscribers.Add(new MessageSubscription<T>()
{
Message = message,
MessageActionWithArgs = action
});
}
public void Subscribe(string message, Action action)
{
subscribers.Add(new MessageSubscription<bool>()
{
Message = message,
MessageActionNoArgs = action
});
}
public void Send<T>(string message, T args)
{
IEnumerable<IMessageSubscription> matches = subscribers.Where(x => x.Message == message && x.PayLoadType == typeof(T));
foreach (IMessageSubscription sub in matches.ToList())
{
sub.InvokeMessageAction((T)args);
}
}
public void Send(string message)
{
IEnumerable<IMessageSubscription> matches = subscribers.Where(x => x.Message == message);
foreach (IMessageSubscription sub in matches.ToList())
{
sub.InvokeMessageAction();
}
}
}
So, for example, MainViewModel would listen for a message such as "ActiveViewModelChangeRequest", and other viewmodels would send that message when they need to become active. So, in MainViewModel you would have something like this:
public MainViewModel()
{
messageService.Register<ViewModelBase>("ActiveViewModelChangeRequest", UpdateActiveViewModel);
}
private void UpdateActiveViewModel(ViewModelBase viewModel)
{
this.CurrentVM = viewModel;
}
And then in UserListVM you would have:
private void OnUserSelect(object sender, UserSelectionEventArgs e)
{
UserVM viewModel = new UserVM(SelectedUser);
messageService.Send<ViewModelBase>("ActiveViewModelChangeRequest, viewModel);
}
There's a lot of reading material available on the messenger pattern for MVVM applications. I would suggest reading up on this.
See the next post. This original one question content has been removed, as doesn't have any sense. Briefly, I asked how to bind XML (which I generated by mistake while parsing DLL assembly) to TreeView using XmlDataProvider in MVVM way. But later I understood that this approach was wrong, and I switched to generation of data entity model (just write classes which represent all the entities I would like to expose in the tree) instead of XML.
So, the result in the next post. Currently from time to time I update this "article", so F5, and
Enjoy reading!
Introduction
The right way I had found reading this article
It's a long story, most of you just can skip it :) But those, who want to understand the problem and solution, must read this all !
I'm QA, and some time ago had become responsible for Automation of the product I clicks. Fortunately, this automaton takes place not in some Testing Tool, but in Visual Studio, so it is maximally close to development.
For our automation we use a framework which consist of MbUnit (Gallio as runner) and of MINT (addition to MbUnit, which is written by the customer we work with). MbUnit gives us Test Fixtures and Tests, and MINT adds additional smaller layer -- Actions inside tests. Example. Fixture is called 'FilteringFixture'. It consist of amount of tests like 'TestingFilteringById', or 'TestingFilteringWithSpecialChars', etc. Each test consist of actions, which are atomic unit of our test. Example of actions are - 'Open app (parameter)', 'OpenFilterDialog', etc.
We already have a lot of tests, which contain a lot of actions, it's a mess. They use internal API of the product we QA. Also, we start investigation a new Automation approach - UI automation via Microsoft UI Automation (sorry for tautology). So the necessity of some "exporter", or "reporter" tool became severe for managers.
Some time ago I have got a task to develop some application, which can parse a DLL (which contains all the fixtures, tests and actions), and export its structure in the human readable format (TXT, HTML, CSV, XML, any other). But, right after that, I went to vacation (2 weeks).
It happens so, that my girlfriend went to her family until vacation (she also got it), and I remained at home so alone. Thinking what me to do all this time (2 weeks), I remember about that "write exporter tool task" and how long I have been planning to start learning WPF. So, I decided to make my task during vacation, and also dress a application to WPF. At that time I heard something about MVVM, and I decided to implement it using pure MVVM.
DLL which can parse DLL with fixrtures etc had been written rather fast (~1-2 days). After that I had started with WPF, and this article will show you how it ended.
I have spent a major part of my vacation (almost 8 days!), trying to sorted it out in my head and code, and finally, it is done (almost). My girlfriend would not believe what I was doing all this time, but I have a proof!
Sharing my solution step by step in pseudo code, to help others avoid similar problems. This answer is more looks like tutorial =) (Really?). If you are interested what were the most complicated things while learning WPF from scratch, I would say -- make it all really MVVM and f*g TreeView binding!
If you want an archived file with solution, I can give it a bit later, just when I have made a decision, that it is worth of that. One limitation, I'm not sure I may share the MINT.dll, which brings Actions, as it has been developed by the customer of our company. But I can just remove it, and share the application, which can display information about Fixtures and Tests only, but not about actions.
Boastful words. With just a little C# / WinForms / HTML background and no practice I have been able to implement this version of the application in almost 1 week (and write this article). So, impossible is possible! Just take a vacation like me, and spend it to WPF learning!
Step by step tutorial (w/o attached files yet)
Short repetition of the task:
Some time ago I have got a task to develop an application, which can parse a DLL (which contains test fixtures, test methods and actions - units of our unit testing based automation framework), and export its structure in the human readable format (TXT, HTML, CSV, XML, any other). I decided to implement it using WPF and pure MVVM (both were absolutely new things for me). The 2 most difficult problems for me became MVVM approach itself, and then MVVM binding to TreeView control. I skip the part about MVVM division, it's a theme for separate article. The steps below are about binding to TreeView in MVVM way.
Not so important: Create DLL which can open DLL with unit tests and finds fixtures, test methods and actions (more smaller level of unit test, written in our company) using reflection. If you are interested in how it had been done, look here: Parsing function / method content using Reflection
DLL: Separated classes are created for both fixtures, tests and actions (data model, entity model?).We'll use them for binding. You should think by yourself, what will be an entity model for your tree. Main idea - each level of tree should be exposed by appropriate class, with those properties, which help you to represent the model in the tree (and, ideally, will take right place in your MVVM, as model or part of the model). In my case, I was interested in entity name, list of children and ordinal number. Ordinal number is a number, which represents order of an entity in the code inside DLL. It helps me show ordinal number in the TreeView, still not sure it's right approach, but it works!
public class MintFixutre : IMintEntity
{
private readonly string _name;
private readonly int _ordinalNumber;
private readonly List<MintTest> _tests = new List<MintTest>();
public MintFixutre(string fixtureName, int ordinalNumber)
{
_name = fixtureName;
if (ordinalNumber <= 0)
throw new ArgumentException("Ordinal number must begin from 1");
_ordinalNumber = ordinalNumber;
}
public List<MintTest> Tests
{
get { return _tests; }
}
public string Name { get { return _name; }}
public bool IsParent { get { return true; } }
public int OrdinalNumber { get { return _ordinalNumber; } }
}
public class MintTest : IMintEntity
{
private readonly string _name;
private readonly int _ordinalNumber;
private readonly List<MintAction> _actions = new List<MintAction>();
public MintTest(string testName, int ordinalNumber)
{
if (string.IsNullOrWhiteSpace(testName))
throw new ArgumentException("Test name cannot be null or space filled");
_name = testName;
if (ordinalNumber <= 0)
throw new ArgumentException("OrdinalNumber must begin from 1");
_ordinalNumber = ordinalNumber;
}
public List<MintAction> Actions
{
get { return _actions; }
}
public string Name { get { return _name; } }
public bool IsParent { get { return true; } }
public int OrdinalNumber { get { return _ordinalNumber; } }
}
public class MintAction : IMintEntity
{
private readonly string _name;
private readonly int _ordinalNumber;
public MintAction(string actionName, int ordinalNumber)
{
_name = actionName;
if (ordinalNumber <= 0)
throw new ArgumentException("Ordinal numbers must begins from 1");
_ordinalNumber = ordinalNumber;
}
public string Name { get { return _name; } }
public bool IsParent { get { return false; } }
public int OrdinalNumber { get { return _ordinalNumber; } }
}
BTW, I also created an interface below, which implement all the entities. Such interface can help you in the future. Still not sure, should I was also add there Childrens property of List<IMintEntity> type, or something like that?
public interface IMintEntity
{
string Name { get; }
bool IsParent { get; }
int OrdinalNumber { get; }
}
DLL - building data model: DLL has a method which opens DLL with unit tests and enumerating data. During enumeration, it builds a data model like below. Real method example is given, reflection core + Mono.Reflection.dll are used, don't be confused with complexity. All that you need - look how the method fills _fixtures list with entities.
private void ParseDllToEntityModel()
{
_fixutres = new List<MintFixutre>();
// enumerating Fixtures
int f = 1;
foreach (Type fixture in AssemblyTests.GetTypes().Where(t => t.GetCustomAttributes(typeof(TestFixtureAttribute), false).Length > 0))
{
var tempFixture = new MintFixutre(fixture.Name, f);
// enumerating Test Methods
int t = 1;
foreach (var testMethod in fixture.GetMethods().Where(m => m.GetCustomAttributes(typeof(TestAttribute), false).Length > 0))
{
// filtering Actions
var instructions = testMethod.GetInstructions().Where(
i => i.OpCode.Name.Equals("newobj") && ((ConstructorInfo)i.Operand).DeclaringType.IsSubclassOf(typeof(BaseAction))).ToList();
var tempTest = new MintTest(testMethod.Name, t);
// enumerating Actions
for ( int a = 1; a <= instructions.Count; a++ )
{
Instruction action = instructions[a-1];
string actionName = (action.Operand as ConstructorInfo).DeclaringType.Name;
var tempAction = new MintAction(actionName, a);
tempTest.Actions.Add(tempAction);
}
tempFixture.Tests.Add(tempTest);
t++;
}
_fixutres.Add(tempFixture);
f++;
}
}
DLL: Public property Fixtures of the List<MintFixutre> type is created to return just created data model ( List of Fixtures, which contain lists of tests, which contains lists of Actions ). This will be our binding source for TreeView.
public List<MintFixutre> Fixtures
{
get { return _fixtures; }
}
ViewModel of MainWindow (with TreeView inside): Contains object / class from DLL which can parse unit tests DLLs. Also exposes Fixtures public property from the DLL of List<MintFixutre> type. We will bind to it from XAML of MainWindow. Something like that (simplified):
var _exporter = MySuperDllReaderExporterClass ();
// public property of ViewModel for TreeView, which returns property from #4
public List<MintFixture> Fixtures { get { return _exporter.Fixtures; }}
// Initializing exporter class, ParseDllToEntityModel() is called inside getter
// (from step #3). Cool, we have entity model for binding.
_exporter.PathToDll = #"open file dialog can help";
// Notifying all those how are bound to the Fixtures property, there are work for them, TreeView, are u listening?
// will be faced later in this article, anticipating events
OnPropertyChanged("Fixtures");
XAML of MainWindow - Setup data templates: Inside a Grid, which contains TreeView, we create <Grid.Resources> section, which contains a set of templates for our TreeViewItems. HierarchicalDataTemplate (Fixtures and Tests) is used for those who have child items, and DataTemplate is used for "leaf" items (Actions). For each template, we specify which its Content (text, TreeViewItem image, etc.), ItemsSource (in case of this item has children, e.g. for Fixtures it is {Binding Path=Tests}), and ItemTemplate (again, only in case this item has children, here we set linkage between templates - FixtureTemplate uses TestTemplate for its children, TestTemplate uses ActionTemplate for its children, Action template does not use anything, it is a leaf!). IMPORTANT: Don't forget, that in order to "link" "one" template to "another", the "another" template must be defined in XAML above the "one"! (just enumerating my own blunders :) )
XAML - TreeView linkage: We setup TreeView with: linking with data model from ViewModel (remember public property?) and with just prepared templates, which represent content, appearance, data sources and nesting of tree items! One more important note. Don't define your ViewModel as "static" resource inside XAML, like <Window.Resources><MyViewModel x:Key="DontUseMeForThat" /></Window.Resources>. If you do so, then you won't be able to notify it on property changed. Why? Static resource is static resource, it initializes ones, and after that remains immutable. I might be wrong here, but it was one of my blunders. So for TreeView use ItemsSource="{Binding Fixtures}" instead of ItemsSource="{StaticResource myStaticViewModel}"
ViewModel - ViewModelBase - Property Changed: Almost all. Stop! When user opens an application, then initially TreeView is empty of course, as user hasn't opened any DLL yet! We must wait until user opens a DLL, and only then perform binding. It is done via OnPropertyChanged event. To make life easier, all my ViewModels are inherited from ViewModelBase, which right exposes this functionality to all my ViewModel.
public class ViewModelBase : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
protected virtual void OnPropertyChanged(string propertyName)
{
OnPropertyChanged(new PropertyChangedEventArgs(propertyName));
}
protected virtual void OnPropertyChanged(PropertyChangedEventArgs args)
{
var handler = PropertyChanged;
if (handler != null)
handler(this, args);
}
}
XAML - OnPropertyChanged and commanding. User clicks a button to opens DLL which contains unit tests data. As we using MVVM, then click is handled via commanding. At the end of the OpenDllExecuted handler OnPropertyChanged("Fixtures") is executed, notifying the Tree, that the property, to which it is bind to has been changed, and that now is time to refresh itself. RelayCommand helper class can be taken for example from there). BTW, as I know, there are some helper libraries and toolkits exist Something like that happens in the XAML:
And ViewModel - Commanding
private ICommand _openDllCommand;
//...
public ICommand OpenDllCommand
{
get { return _openDllCommand ?? (_openDllCommand = new RelayCommand(OpenDllExecuted, OpenDllCanExecute)); }
}
//...
// decides, when the <OpenDll> button is enabled or not
private bool OpenDllCanExecute(object obj)
{
return true; // always true for Open DLL button
}
//...
// in fact, handler
private void OpenDllExecuted(object obj)
{
var openDlg = new OpenFileDialog { ... };
_pathToDll = openDlg.FileName;
_exporter.PathToDll = _pathToDll;
// Notifying TreeView via binding that the property <Fixtures> has been changed,
// thereby forcing the tree to refresh itself
OnPropertyChanged("Fixtures");
}
Final UI (but not final for me, a lot of things should be done!). Extended WPF toolkit was used somewhere: http://wpftoolkit.codeplex.com/
I'm moving to using the SimpleIoc for Dependency Injection from using a Static class. There is a Register<TClass>(Func<TClass> factory) where TClass : class method in the SimpleIoc, but I can't find any examples of using it. Here's a link to the source code.
Am I approaching this correctly, or does DI always need to create it at register time? Is this the method I should use to register the class? Can you give me an example on how to do this?
This is the Silverlight code I'm trying to update.
EDIT: moved my approach to an answer
I moved my example from my question to an answer, since no one else has answered it in 22 days. EDIT: this is better.
public partial class App : Application
{
/// <summary>
/// Initializes a new instance of the <see cref="App"/> class.
/// </summary>
public App()
{
this.Startup += (s, e) =>
{
// create and register it now
SimpleIoc.Default.Register<IUserToken>(() => { return new UserToken(); });
SimpleIoc.Default.GetInstance<IUserToken>().PopulateUserTokenFromService(() =>
{
// don't do anything until the user token is populated from the server
InitializeComponent();
this.RootVisual = new View();
});
}
}
I am writing an WPF MVVM application using Prism. A couple days ago I asked about best practices for managing different views and didn't get a whole lot of feedback. Sense then I have come up with a system that seems to work, but I want to make sure I wont get bit down the road.
I followed the tutorials at http://development-guides.silverbaylabs.org/ to get my shell setup and am confident that my modules are being registered well.
However, nowhere in those tutorials was an example of a view being replaced with a different view within a given region. This in general, seems to be fairly hard to find a good example of. So, today I rolled my own solution to the problem.
Essentially the module has a controller that keeps track of the current view, then when the user wants to switch views, it calls the Regions.Remove command and then the add command to replace it with the current view. It seems like there must be a more elegant solution to just switch between different registered views, but I haven't found it.
All the different possible views for a module are registered with the Unity container when the module is initialized.
The controller and the view switching function follows:
namespace HazardModule
{
public class HazardController : IHazardController
{
private object CurrentView;
public IRegionManager RegionManager { get; set; }
private IUnityContainer _container;
public HazardController(IUnityContainer container)
{
_container = container;
}
/// <summary>
/// Switches the MainRegion view to a different view
/// </summary>
/// <typeparam name="T">The class of the view to switch to</typeparam>
public void SiwthToView<T>()
{
if (CurrentView != null)
{
RegionManager.Regions["MainRegion"].Remove(CurrentView);
}
CurrentView = _container.Resolve<T>();
RegionManager.Regions["MainRegion"].Add(CurrentView);
}
}
}
Any feedback or other better solutions would be appreciated.
I have pretty much the same approach, so does a co-worker who has a bit more Prism experience than myself.
Basically I have a ViewController class which is a property in my ViewModelBase class. This enables all my ViewModels to have access to it in one go. Then in my ViewController class I have a few display management methods. The correctness of this approach is probably debatable but I found it to work quite well in my case
public TView ShowViewInRegion<TView>(string regionName, string viewName, bool removeAllViewsFromRegion)
{
var region = regionManager.Regions[regionName];
var view = region.GetView(viewName) ?? container.Resolve<TView>();
if (removeAllViewsFromRegion)
{
RemoveViewsFromRegion(region);
}
region.Add(view, viewName);
region.Activate(view);
if (regionName == RegionNames.OverlayRegion)
{
eventAggregator.GetEvent<PopupWindowVisibility>().Publish(true);
}
return (TView)view;
}
public void RemoveViewsFromRegion(string regionName)
{
RemoveViewsFromRegion(regionManager.Regions[regionName]);
}
private void RemoveViewsFromRegion(IRegion region)
{
for (int i = 0; i < region.Views.Count() + i; i++)
{
var view = region.Views.ElementAt(0);
region.Remove(view);
}
if (region.Name == RegionNames.OverlayRegion)
{
eventAggregator.GetEvent<PopupWindowVisibility>().Publish(false);
}
}
private static void DeactivateViewsInRegion(IRegion region)
{
for (var i = 0; i < region.ActiveViews.Count(); i++)
{
var view = region.ActiveViews.ElementAt(i);
region.Deactivate(view);
}
}
Then whenever I need to switch out a view or whatever I can just call from my ViewModel
public void ExecuteCreateUserCommand()
{
ViewController.ShowViewInRegion<IUserCreateView>(RegionNames.ContentRegion, ViewNames.UserCreateView, true);
}
I am trying to unit test my WPF databindings using the test suit provided by Microsoft Team System. I would like to be able to test the bindings without showing the window because most of my tests will be for user controls and not actually on a window. Is this possible or is there a better way to do it? The code below works if I show the window, but if I don't, the bindings don't update.
Window1_Accessor target = new Window1_Accessor();
UnitTestingWPF.Window1_Accessor.Person p = new UnitTestingWPF.Window1_Accessor.Person() { FirstName = "Shane" };
Window1 window = (target.Target as Window1);
window.DataContext = p;
//window.Show(); //Only Works when I actually show the window
//Is it possible to manually update the binding here, maybe? Is there a better way?
Assert.AreEqual("Shane", target.textBoxFirstName.Text); //Fails if I don't Show() the window because the bindings aren't updated
While looking for a solution to convert WPF binding errors into exception, I figured out that it can also be used in a unit test project.
The technique is very simple:
Derive a TraceListener that throws instead of logging
Add that listener to PresentationTraceSources.DataBindingSource
Please see the complete solution on GitHub, it includes a unit test project.
Shane, if what you're really worried about is a binding breaking silently, you should look at redirecting the binding traces to somewhere you can examine. I'd start here:
http://blogs.msdn.com/mikehillberg/archive/2006/09/14/WpfTraceSources.aspx
Other than that, I agree with Gishu that bindings aren't good candidates for unit testing, mainly due to the automagic going on that Gishu mentioned in the "Epilogue". Instead focus on making sure the underlying class behaves correctly.
Note, too, that you can get even more robust traces using the PresentationTraceSources class:
http://msdn.microsoft.com/en-us/library/system.diagnostics.presentationtracesources.aspx
Hope that helps!
Eyeball it.
This kind of declarative markup rarely breaks.. unless someone goes in manual and screws it up. Even then, you can fix it within minutes. IMHO the cost of writing such tests far outweigh the benefits.
Update[Dec3,08]: Alrighty then.
The test is just testing that the textbox has the value "FirstName" as the Path property of the binding. If I change/refactor FirstName to JustName in the actual data source object, the test would still pass since it is testing against an anonymous type. (Green test when code broken - TDD Antipattern: The Liar)
If your aim is to verify that FirstName has been specified in XAML,
Assert.AreEqual("FirstName", txtBoxToProbe.GetBindingExpression(TextBox.TextProperty).ParentBinding.Path.Path);
If you really must catch broken bindings via unit tests (and don't want to show the UI), use the real data source... struggled for a while and came up with this.
[Test]
public void TestTextBoxBinding()
{
MyWindow w = new MyWindow();
TextBox txtBoxToProbe = w.TextBox1;
Object obDataSource = w; // use 'real' data source
BindingExpression bindingExpr = BindingOperations.GetBindingExpression(txtBoxToProbe, TextBox.TextProperty);
Binding newBind = new Binding(bindingExpr.ParentBinding.Path.Path);
newBind.Source = obDataSource;
txtBoxToProbe.SetBinding(TextBox.TextProperty, newBind);
Assert.AreEqual("Go ahead. Change my value.", txtBoxToProbe.Text);
}
Epilogue:
There's some real covert stuff happening in the call to Window.Show(). It somehow magically sets up the DataItem property after which data binding starts working.
// before show
bindingExpr.DataItem => null
bindingExpr.Status => BindingStatus.Unattached
// after show
bindingExpr.DataItem => {Actual Data Source}
bindingExpr.Status => BindingStatus.Active
Once the Binding is Active, I guess you can force textbox updates via code like this..
txtBoxToProbe.GetBindingExpression(TextBox.TextProperty).UpdateTarget();
Once again, I voice my reluctance against this approach. Getting NUnit to run in STA was a pain..
Combining advice I came across in a number of SO posts I wrote the following class which works very well to test WPF bindings.
public static class WpfBindingTester
{
/// <summary>load a view in a hidden window and monitor it for binding errors</summary>
/// <param name="view">a data-bound view to load and monitor for binding errors</param>
public static void AssertBindings(object view)
{
using (InternalTraceListener listener = new InternalTraceListener())
{
ManualResetEventSlim mre = new ManualResetEventSlim(false);
Window window = new Window
{
Width = 0,
Height = 0,
WindowStyle = WindowStyle.None,
ShowInTaskbar = false,
ShowActivated = false,
Content = view
};
window.Loaded += (_, __) => mre.Set();
window.Show();
mre.Wait();
window.Close();
Assert.That(listener.ErrorMessages, Is.Empty, listener.ErrorMessages);
}
}
/// <summary>Is the test running in an interactive session. Use with Assume.That(WpfBindingTester.IsAvailable) to make sure tests only run where they're able to</summary>
public static bool IsAvailable { get { return Environment.UserInteractive && Process.GetCurrentProcess().SessionId != 0; } }
private class InternalTraceListener : TraceListener
{
private readonly StringBuilder _errors = new StringBuilder();
private readonly SourceLevels _originalLevel;
public string ErrorMessages { get { return _errors.ToString(); } }
static InternalTraceListener() { PresentationTraceSources.Refresh(); }
public InternalTraceListener()
{
_originalLevel = PresentationTraceSources.DataBindingSource.Switch.Level;
PresentationTraceSources.DataBindingSource.Switch.Level = SourceLevels.Error;
PresentationTraceSources.DataBindingSource.Listeners.Add(this);
}
public override void Write(string message) {}
public override void WriteLine(string message) { _errors.AppendLine(message); }
protected override void Dispose(bool disposing)
{
PresentationTraceSources.DataBindingSource.Listeners.Remove(this);
PresentationTraceSources.DataBindingSource.Switch.Level = _originalLevel;
base.Dispose(disposing);
}
}
}
you can try Guia.
With it you can unit-test your UserControl and check if the data binding is correct. You have to show the window though.
Here is an example. It starts a new instance of your UserControl and sets its DataContext and then checks if the textbox is set to the right value.
[TestMethod]
public void SimpleTest()
{
var viewModel = new SimpleControlViewModel() {TextBoxText = "Some Text"};
customControl = CustomControl.Start<SimpleUserControl>((control) => control.DataContext = viewModel);
Assert.AreEqual("Some Text", customControl.Get<TextBox>("textbox1").Value);
customControl.Stop();
}