PresentationBase 3.3.0

A lightweight MVVM implementation for WPF (Windows Presentation Foundation) targeting both .NET Framework and .NET Core.

There is a newer prerelease version of this package available.
See the version list below for details.
Install-Package PresentationBase -Version 3.3.0
dotnet add package PresentationBase --version 3.3.0
<PackageReference Include="PresentationBase" Version="3.3.0" />
For projects that support PackageReference, copy this XML node into the project file to reference the package.
paket add PresentationBase --version 3.3.0
The NuGet Team does not provide support for this client. Please contact its maintainers for support.

Take a look at the Quick start in the wiki. Here are some basic examples:

ViewModels with bindable properties

// C# code
public class AwesomeViewModel : ViewModel
{
    private string _name;
  
    public string Name
    {
        get => _name;
        set => SetProperty(ref _name, value);
    }
}
<!-- XAML -->
<TextBox Text="{Binding Name, UpdateSourceTrigger=PropertyChanged}" />

... and with property validation

// C# code
public class AwesomeViewModel : ViewModel
{
    private string _name;

    public string Name
    {
        get => _name;
        set => SetProperty(ref _name, value, NameValidation);
    }

    private IEnumerable<string> NameValidation(string value)
    {
        if (string.IsNullOrEmpty(value))
            yield return "Name cannot be null or empty!";
        else if (value == "sungaila")
            yield return "Name cannot be stupid!";
    }
}
<!-- XAML -->
<TextBox Text="{Binding Name, UpdateSourceTrigger=PropertyChanged}" />

ViewModel collections

// C# code
public class AwesomeViewModel : ViewModel
{
    public ObservableViewModelCollection<ChildViewModel> Children { get; }
    
    public AwesomeViewModel()
    {
        Children = new ObservableViewModelCollection<ChildViewModel>(this);
        Children.Add(new ChildViewModel { Nickname = "Blinky" });
        Children.Add(new ChildViewModel { Nickname = "Pinky" });
        Children.Add(new ChildViewModel { Nickname = "Inky" });
        Children.Add(new ChildViewModel { Nickname = "Clyde" });
    }
}
<!-- XAML -->
<ListView ItemsSource="{Binding Children}">
    <ListView.ItemTemplate>
        <DataTemplate>
            <TextBlock Text="{Binding Nickname}" />
        </DataTemplate>
    </ListView.ItemTemplate>
</ListView>

... and collection compositions

// C# code
public class AwesomeViewModel : ViewModel
{
    public ObservableViewModelCollection<ChildViewModel> Children { get; }

    public ObservableViewModelCollection<PersonViewModel> People { get; }

    public CompositeViewModelCollection<ViewModel> Composition { get; }
    
    public AwesomeViewModel()
    {
        Children = new ObservableViewModelCollection<ChildViewModel>(this);
        Children.Add(new ChildViewModel { Nickname = "Blinky" });
        Children.Add(new ChildViewModel { Nickname = "Pinky" });
        Children.Add(new ChildViewModel { Nickname = "Inky" });
        Children.Add(new ChildViewModel { Nickname = "Clyde" });

        People = new ObservableViewModelCollection<PersonViewModel>(this);
        People.Add(new PersonViewModel { Nickname = "Kevin" });
        People.Add(new PersonViewModel { Nickname = "Tommy" });

        Composition = new CompositeViewModelCollection<ViewModel>();
        Composition.Add(Children);
        Composition.Add(People);
    }
}
<!-- XAML -->
<ListView ItemsSource="{Binding Composition}">
    <ListView.ItemTemplate>
        <DataTemplate>
            <TextBlock Text="{Binding Nickname}" />
        </DataTemplate>
    </ListView.ItemTemplate>
</ListView>

Commands

Your command can be defined anywhere you want (as long as its assembly is referenced by the WPF application). Please note that a parameterless constructor (or none at all) is needed.

// C# code
public class AlertCommand : ViewModelCommand<AwesomeViewModel>
{
    public override void Execute(AwesomeViewModel parameter)
    {
        System.Windows.MessageBox.Show("You just clicked that button.");
    }

    public override bool CanExecute(AwesomeViewModel parameter)
    {
        return parameter.Name != "John Doe";
    }
}

The only reference needed is the x:Type in XAML. Important: Make sure to write CommandParameter before Command to avoid problems with CanExecute. Consider to create an issue for the .NET Core team (like this one) if you want this WPF bug fixed.

<!-- XAML -->
<Window x:Class="WpfApp.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:Core="clr-namespace:PresentationBase;assembly=PresentationBase"
        xmlns:local="clr-namespace:WpfApp">
        
        <Button CommandParameter="{Binding}"
                Command="{Core:CommandBinding {x:Type local:AlertCommand}}" />
</Window>

... and async commands

// C# code
public class AlertCommandAsync : ViewModelCommandAsync<AwesomeViewModel>
{
    protected override async Task ExecutionAsync(AwesomeViewModel parameter)
    {
        await Task.Run(() =>
        {
            System.Threading.Thread.Sleep(2000);
            System.Windows.MessageBox.Show("You clicked that button two seconds ago.");
        });
    }
}
<!-- XAML -->
<Window x:Class="WpfApp.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:Core="clr-namespace:PresentationBase;assembly=PresentationBase"
        xmlns:local="clr-namespace:WpfApp">
        
        <Button CommandParameter="{Binding}"
                Command="{Core:CommandBinding {x:Type local:AlertCommandAsync}}" />
</Window>

ValueConverters

<!-- XAML -->
<Window x:Class="WpfApp.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:Converters="clr-namespace:PresentationBase.Converters;assembly=PresentationBase"
        xmlns:local="clr-namespace:WpfApp">
        
        <TextBox Visibility="{Binding Name, Converter={Converters:NullToVisibilityConverter}}" />
</Window>

Take a look at the Quick start in the wiki. Here are some basic examples:

ViewModels with bindable properties

// C# code
public class AwesomeViewModel : ViewModel
{
    private string _name;
  
    public string Name
    {
        get => _name;
        set => SetProperty(ref _name, value);
    }
}
<!-- XAML -->
<TextBox Text="{Binding Name, UpdateSourceTrigger=PropertyChanged}" />

... and with property validation

// C# code
public class AwesomeViewModel : ViewModel
{
    private string _name;

    public string Name
    {
        get => _name;
        set => SetProperty(ref _name, value, NameValidation);
    }

    private IEnumerable<string> NameValidation(string value)
    {
        if (string.IsNullOrEmpty(value))
            yield return "Name cannot be null or empty!";
        else if (value == "sungaila")
            yield return "Name cannot be stupid!";
    }
}
<!-- XAML -->
<TextBox Text="{Binding Name, UpdateSourceTrigger=PropertyChanged}" />

ViewModel collections

// C# code
public class AwesomeViewModel : ViewModel
{
    public ObservableViewModelCollection<ChildViewModel> Children { get; }
    
    public AwesomeViewModel()
    {
        Children = new ObservableViewModelCollection<ChildViewModel>(this);
        Children.Add(new ChildViewModel { Nickname = "Blinky" });
        Children.Add(new ChildViewModel { Nickname = "Pinky" });
        Children.Add(new ChildViewModel { Nickname = "Inky" });
        Children.Add(new ChildViewModel { Nickname = "Clyde" });
    }
}
<!-- XAML -->
<ListView ItemsSource="{Binding Children}">
    <ListView.ItemTemplate>
        <DataTemplate>
            <TextBlock Text="{Binding Nickname}" />
        </DataTemplate>
    </ListView.ItemTemplate>
</ListView>

... and collection compositions

// C# code
public class AwesomeViewModel : ViewModel
{
    public ObservableViewModelCollection<ChildViewModel> Children { get; }

    public ObservableViewModelCollection<PersonViewModel> People { get; }

    public CompositeViewModelCollection<ViewModel> Composition { get; }
    
    public AwesomeViewModel()
    {
        Children = new ObservableViewModelCollection<ChildViewModel>(this);
        Children.Add(new ChildViewModel { Nickname = "Blinky" });
        Children.Add(new ChildViewModel { Nickname = "Pinky" });
        Children.Add(new ChildViewModel { Nickname = "Inky" });
        Children.Add(new ChildViewModel { Nickname = "Clyde" });

        People = new ObservableViewModelCollection<PersonViewModel>(this);
        People.Add(new PersonViewModel { Nickname = "Kevin" });
        People.Add(new PersonViewModel { Nickname = "Tommy" });

        Composition = new CompositeViewModelCollection<ViewModel>();
        Composition.Add(Children);
        Composition.Add(People);
    }
}
<!-- XAML -->
<ListView ItemsSource="{Binding Composition}">
    <ListView.ItemTemplate>
        <DataTemplate>
            <TextBlock Text="{Binding Nickname}" />
        </DataTemplate>
    </ListView.ItemTemplate>
</ListView>

Commands

Your command can be defined anywhere you want (as long as its assembly is referenced by the WPF application). Please note that a parameterless constructor (or none at all) is needed.

// C# code
public class AlertCommand : ViewModelCommand<AwesomeViewModel>
{
    public override void Execute(AwesomeViewModel parameter)
    {
        System.Windows.MessageBox.Show("You just clicked that button.");
    }

    public override bool CanExecute(AwesomeViewModel parameter)
    {
        return parameter.Name != "John Doe";
    }
}

The only reference needed is the x:Type in XAML. Important: Make sure to write CommandParameter before Command to avoid problems with CanExecute. Consider to create an issue for the .NET Core team (like this one) if you want this WPF bug fixed.

<!-- XAML -->
<Window x:Class="WpfApp.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:Core="clr-namespace:PresentationBase;assembly=PresentationBase"
        xmlns:local="clr-namespace:WpfApp">
        
        <Button CommandParameter="{Binding}"
                Command="{Core:CommandBinding {x:Type local:AlertCommand}}" />
</Window>

... and async commands

// C# code
public class AlertCommandAsync : ViewModelCommandAsync<AwesomeViewModel>
{
    protected override async Task ExecutionAsync(AwesomeViewModel parameter)
    {
        await Task.Run(() =>
        {
            System.Threading.Thread.Sleep(2000);
            System.Windows.MessageBox.Show("You clicked that button two seconds ago.");
        });
    }
}
<!-- XAML -->
<Window x:Class="WpfApp.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:Core="clr-namespace:PresentationBase;assembly=PresentationBase"
        xmlns:local="clr-namespace:WpfApp">
        
        <Button CommandParameter="{Binding}"
                Command="{Core:CommandBinding {x:Type local:AlertCommandAsync}}" />
</Window>

ValueConverters

<!-- XAML -->
<Window x:Class="WpfApp.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:Converters="clr-namespace:PresentationBase.Converters;assembly=PresentationBase"
        xmlns:local="clr-namespace:WpfApp">
        
        <TextBox Visibility="{Binding Name, Converter={Converters:NullToVisibilityConverter}}" />
</Window>

Release Notes

Updates coming from PresentationBase.Core 3.3.0:
- Added TrxViewModel for short-term and long-term rollbacks
- ViewModel implements INotifyPropertyChanging now

NuGet packages

This package is not used by any NuGet packages.

GitHub repositories

This package is not used by any popular GitHub repositories.

Version History

Version Downloads Last updated
3.4.0-preview 64 11/11/2020
3.3.0 226 9/20/2020
3.2.0 83 8/24/2020
3.1.0 124 6/26/2020
3.0.0 142 5/20/2020
2.3.1 127 3/24/2020
2.3.0 156 1/19/2020
2.2.1 170 1/15/2020
2.2.0 159 1/4/2020
2.1.2 126 12/25/2019
2.0.3 162 12/22/2019