MVVM Light Toolkit

New Post: Cross Platform WinRT+WP8

lbugnion — Thu, 23 May 2013 16:42:47 GMT

Please make sure that you are also referencing the MVVM Light PCL assemblies in the two applications (WinRT and WP8).

Let me know if that solves the issue.

Cheers
Laurent

New Post: Cross Platform WinRT+WP8

mrprogle — Thu, 23 May 2013 08:32:56 GMT

hi,

I am dealing with a project which it has two side,both WinRT and WP8.
My goal is taking ViewModels and Models to in a common area
(for now I'm using portable library for it)
for using same ViewModels and Models in both solution.

But When i am building the solution, i get some error like
"Cannot resolve Assembly or Windows Metadata file 'GalaSoft.MvvmLight.dll'"

What am I doing wrong! or you can suggest the way i must follow.

Thanks for you great framework.

New Post: Could not load type 'INotifyPropertyChanging' error in VS 2012 Premium with MvvmLight 4.1.24.0

Familyghost — Sun, 19 May 2013 18:13:41 GMT

Sure thing Laurent, see attached.

I find I have to compile and run in more than once to see the error in the designer window.

Maybe you can tell me why my listbox data isn’t binding. I’m out of ideas.

Thanks,

Chris

New Post: Could not load type 'INotifyPropertyChanging' error in VS 2012 Premium with MvvmLight 4.1.24.0

lbugnion — Sun, 19 May 2013 13:21:36 GMT

Hi,

I don’t see the error. I tried adding mvvmlight through Nuget in a Windows Phone 7.1 and in a Windows Phone 8 app and both times I was able to wire the VM, add a property, and see everything in the VS designer.

Can you send me the app you did, including the packages folder with the downloaded DLLs?

Thanks

Laurent

Commented Issue: Register throws exception when class without ctor and static field is registered [7595]

Necroman — Sun, 19 May 2013 09:51:39 GMT

See this question (http://stackoverflow.com/questions/13284526/in-winrt-static-field-not-initialized-at-all/13285323#13285323) on Stackoverflow.

The problem is the method GetConstructorInfo in the SimpleIoc class which throws an exception "Multiple constructors found but none marked with PreferredConstructor", cause the class has a default ctor and a static ctor.
Comments: Same here, I got these two constructors in MainViewModel, but I am getting exception that none has PreferredConstructor attribute: public MainViewModel() { } [PreferredConstructor] public MainViewModel(INavigationService navigationService) { _navigationService = navigationService; InitializeCommands(); }

Edited Feature: Feature request: IEventArgsConverter for EventToCommand [6908]

lbugnion — Sat, 18 May 2013 21:35:35 GMT

First I'm in the camp were it is unaccaptable to allow UI references in my ViewModel. The ViewModel should not be aware of the View and that includes references to UI elements or anything under System.Windows.Controls namespace. To allow this scenario for RelayCommands that require event arguments this new feature would be needed.

I'd like to be able to handle my event arguements in a converter before it goes to the ViewModel. As of right now the toolkit just sends whatever event arguements are defined by the UI to the ViewModel. Any class implementing IEventArgsConverter would be able intercept the event arguments from an EventToComand and output a System.Object to the wired up RelayCommand. This would work just like we already use System.Windows.Data.IValueConverter in XAML data-binding.

Created Release: MVVM Light V4.2

lbugnion — Sat, 18 May 2013 21:05:05 GMT

Version 4.2

Commented Issue: RelayCommand fails if delegate contains a non-constant method parameter [7605]

AlexPaskhin — Sat, 18 May 2013 16:07:10 GMT

I've come across what I think is a bug in RelayCommand (at least for WPF 4.0):
* If you attempt to construct a RelayCommand with a lambda expression composed entirely of compile-time constants, e.g., __() => DoSomething(2)__, it works as expected.
* However, if the lambda expression contains a method call with a parameter, and the value passed into that parameter is determined at runtime, e.g., __() => DoSomething(number)__, nothing happens when the command is executed.

If you put the code below into a WPF 4.0 project and build it in Debug mode, you will notice that if you click "Do Something", nothing happens, but if you click "Do Something Else", a "2" appears in the output window. (Similarly, if you put a breakpoint in the DoSomething method, it will only be hit if you click "Do Something Else".)

MainWindow.xaml:

```
<Window xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:local="clr-namespace:WpfApplication1"
mc:Ignorable="d"
x:Class="WpfApplication1.MainWindow"
Title="MainWindow"
Height="400"
Width="400">
<Window.DataContext>
<local:MainWindowViewModel />
</Window.DataContext>
<StackPanel>
<Button Content="Do Something"
Command="{Binding DoSomethingCommand}" />
<Button Margin="0,10,0,0"
Content="Do Something Else"
Command="{Binding DoSomethingElseCommand}" />
</StackPanel>
</Window>
```

MainWindowViewModel.cs

```
namespace WpfApplication1
{
public class MainWindowViewModel : ViewModelBase
{
public ICommand DoSomethingCommand { get; private set; }
public ICommand DoSomethingElseCommand { get; private set; }

public MainWindowViewModel()
{
DoSomethingCommand = GetCommand(2);
DoSomethingElseCommand = new RelayCommand(() => DoSomething(2));
}

private ICommand GetCommand(int number)
{
return new RelayCommand(() => DoSomething(number));
}

private void DoSomething(int number)
{
Debug.Print(number.ToString());
}
}
}
```
Comments: Here are links: • MVVM-WPF XAML Mark-up Binding Extensions - http://wpfmvvmbindingext.codeplex.com • MVVM-WPF XAML Mark-up Dependency Injection Binding Extensions - http://wpfmvvmbindingiocext.codeplex.com They will help to solve

New Post: Could not load type 'INotifyPropertyChanging' error in VS 2012 Premium with MvvmLight 4.1.24.0

lbugnion — Fri, 17 May 2013 17:54:06 GMT

I'll check it out.

Cheers
Laurent
--
Laurent Bugnion
Senior Director, IdentityMine
Microsoft Regional Director and MVP
http://www.galasoft.ch | http://www.identitymine.com
Sent from my beautiful Nokia Lumia 920

From: [email removed]
Sent: ‎17.‎05.‎2013 18:20
To: [email removed]
Subject: Re: Could not load type 'INotifyPropertyChanging' error in VS 2012Premium with MvvmLight 4.1.24.0 [mvvmlight:401430]

From: Familyghost

This is update 2, VS 11.0.60315.01

.NET framework 1.5.50709

Sent from Windows Mail

From: lbugnion
Sent: ‎Friday‎, ‎May‎ ‎17‎, ‎2013 ‎11‎:‎16‎ ‎AM
To: [email removed]

From: lbugnion

Hi,

You need to make sure that you are using the latest version of VS (update 2).

The VS designer *is* Blend so you are in fact using it ;)

Cheers
Laurent
--
Laurent Bugnion
Senior Director, IdentityMine
Microsoft Regional Director and MVP
http://www.galasoft.ch | http://www.identitymine.com
Sent from my beautiful Nokia Lumia 920

From: [email removed]
Sent: ‎17.‎05.‎2013 17:56
To: [email removed]
Subject: Re: Could not load type 'INotifyPropertyChanging' error in VS 2012Premium with MvvmLight 4.1.24.0 [mvvmlight:401430]

From: Familyghost

Laurent,

From the thread it sounds like this problem had been patched up by now. I installed MMVM light via nuget a few days ago, For instance System.Windows.Interactivity Verion 3.8.5.0 and still get this error.

I don't use blend. It shows up in the Designer in VS2012 Express for WP

Anything we can do?

Thanks

Commented Issue: mvvminpc snippet not available after nuget-based install? [7574]

ah_lun — Fri, 17 May 2013 16:30:52 GMT

I've created a new WPF application and used nuget to install MVVM Light. The default MainViewModel states in a comment that the "mvvminpc" snippet is available to add bindable properties.

However, typing this snippet doesn't actually do anything nor does it show up in intellisense. How can I make it available?
Comments: I am using VS Express 2012 for Windows Phone on Windows 8 Pro, installed the MVVM Light and the snippets is not showing. There is a solution to manually add the snippet, but couldn't found the folder.

New Post: Could not load type 'INotifyPropertyChanging' error in VS 2012 Premium with MvvmLight 4.1.24.0

Familyghost — Fri, 17 May 2013 16:20:06 GMT

This is update 2, VS 11.0.60315.01

.NET framework 1.5.50709

Sent from Windows Mail

From: lbugnion
Sent: ‎Friday‎, ‎May‎ ‎17‎, ‎2013 ‎11‎:‎16‎ ‎AM
To: [email removed]

From: lbugnion

From: [email removed]
Sent: ‎17.‎05.‎2013 17:56
To: [email removed]
Subject: Re: Could not load type 'INotifyPropertyChanging' error in VS 2012Premium with MvvmLight 4.1.24.0 [mvvmlight:401430]

From: Familyghost

New Post: Could not load type 'INotifyPropertyChanging' error in VS 2012 Premium with MvvmLight 4.1.24.0

lbugnion — Fri, 17 May 2013 16:16:36 GMT

From: [email removed]
Sent: ‎17.‎05.‎2013 17:56
To: [email removed]
Subject: Re: Could not load type 'INotifyPropertyChanging' error in VS 2012Premium with MvvmLight 4.1.24.0 [mvvmlight:401430]

From: Familyghost

New Post: Could not load type 'INotifyPropertyChanging' error in VS 2012 Premium with MvvmLight 4.1.24.0

Familyghost — Fri, 17 May 2013 15:55:18 GMT

New Post: PCL viewModel Win8/phone services async

roschler — Thu, 16 May 2013 18:14:01 GMT

@jhalbrecht - I ran into the same problem with "cannot await" errors. It's some odd incompatibility between Assembly versions. I found this cryptic NuGet issue resolution page on the subject:

http://blogs.msdn.com/b/bclteam/p/asynctargetingpackkb.aspx

I wish they had explained what the problem was and why the fix works, but the fix does work. Here's what they say:

Issue 2

Symptom

After installing the Microsoft.Bcl or Microsoft.Bcl.Async packages to certain projects, you may get build errors or warnings similar to:

Cannot await 'System.Threading.Tasks.Task'.

or

The primary reference "Microsoft.Threading.Tasks" could not be resolved because it has an indirect dependency on the framework assembly "System.Runtime, Version=1.5.10.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" which could not be resolved in the currently targeted framework. ".NETFramework,Version=v4.0". To resolve this problem, either remove the reference "Microsoft.Threading.Tasks" or retarget your application to a framework version which contains "System.Runtime, Version=1.5.10.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a".

Resolution

Microsoft.Bcl.Async package is not supported in Visual Basic Web Application projects. As a workaround, place all async/await usage in a class library and consume that from the Web Application project.

Otherwise, for other project types add an App.Config to the project with the following contents, replacing [version] with the version (for example, 2.5.10.0) of System.Runtime and System.Threading.Tasks that you are referencing:

<?xml version="1.0" encoding="utf-8"?>
<configuration>
<runtime>

<assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
  <dependentAssembly>
    <assemblyIdentity name="System.Runtime" publicKeyToken="b03f5f7f11d50a3a" culture="neutral" />
    <bindingRedirect oldVersion="0.0.0.0-[version]" newVersion="[version]" />
  </dependentAssembly>
  <dependentAssembly>
    <assemblyIdentity name="System.Threading.Tasks" publicKeyToken="b03f5f7f11d50a3a" culture="neutral" />
    <bindingRedirect oldVersion="0.0.0.0-[version]" newVersion="[version]" />
  </dependentAssembly>
</assemblyBinding>

</runtime>
</configuration>

Make sure you capitalize the first word in App.Config. In my case the DLLs I were using were 1.5.11.0 and replacing "version" (no quotes) with that value did the trick. Just check the version number of your System.Runtime and System.Threading.Tasks in the properties window. You'll see it in the path to the DLL(s).

-- roschler

Reviewed: MVVM Light Toolkit V4.1 for Visual Studio 2012 (máj. 13, 2013)

AxelJ — Mon, 13 May 2013 20:32:18 GMT

Rated 5 Stars (out of 5) - gdfgdfgdfgdfgdfgdfgdf

New Post: CanExecute not updating UI when called from background thread

pipjt — Thu, 09 May 2013 19:07:29 GMT

OK, so I have figured out a work around.

Fortunately, the condition on my background thread that I am using to determine the CanExecute state, has an associated event.

I hooked into the event on my ViewModel using a lamda expression for each instance of the object in question, and used the dispatcher helper to call the RaiseCanExecuteChanged on the UI thread for each associated command.

DispatcherHelper.CheckBeginInvokeOnUI(() => { [MyCommand].RaiseCanExecuteChanged(); });

In future, if an event is not available I will consider using the Messenger.

This works but feels a little convoluted; is there a better way of doing this?

Many Thanks

Phil

New Post: Product: MVVM Light Toolkit -- Error 1721. There is a problem with this Windows Installer package

i00b — Thu, 09 May 2013 04:12:35 GMT

I get the following error message (from the event log) when attempting to install GalaSoft.MvvmLight.4.1.24.0.msi:

Product: MVVM Light Toolkit -- Error 1721. There is a problem with this Windows Installer package. A program required for this install to complete could not be run. Contact your support personnel or package vendor. Action: PostSetupActionVS10Machine, location: D:\, command: C:\Users\MYUSERNAME\AppData\Roaming\MvvmLight\ModifyRegistryKey.exe -i10m "C:\Program Files (x86)\Laurent Bugnion (GalaSoft)\Mvvm Light Toolkit\Snippets\CSharp\

A similar error has been reported before (see https://mvvmlight.codeplex.com/discussions/274919). Does this installation package need to be updated (as mentioned in the referenced post) or is there a work around solution?

Thanks,

Ian

New Post: CanExecute not updating UI when called from background thread

pipjt — Tue, 07 May 2013 16:20:08 GMT

Hi Laurent

I appologies if this has been asked before.

I am having an issue with my WPF application (using MVVM Light), where the CanExecute element of the RelayCommand is not updating my UI; this is appears to be becuse it is being updated from a background thread.

Is this something that can be overcome using the DispatcherHelper, if so how?

Many Thanks

Phil

Edited Unassigned: New Messenger.Default.IsRegistered<> to help debugging Messenger issues. [7609]

tryan — Tue, 07 May 2013 14:57:04 GMT

For purposes of Debugging, it would be great to include properties and methods that would help debug whether a particular message has been registered and what class(es) are registered to that message. This would help narrow down issues regarding improper registered\ unregistered of messages.

Created Unassigned: Messenger.Default.IsRegistered<> method returns whether a specific message is registered [7609]

tryan — Tue, 07 May 2013 14:56:25 GMT