Version: 0.10.x

Avalonia is in general very similar to WPF, but you will find differences. Here are the most common:

Dispatcher changes

If you use Application.Current.Dispatcher, you should use Dispatcher.UIThread instead which provide similar facilities.

WPF

Application.Current.Dispatcher.InvokeAsync(handler, DispatcherPriority.Background);

Avalonia

Dispatcher.UIThread.InvokeAsync(handler, DispatcherPriority.Background);

If you previously access dispatcher on the control itself, you should use global static instance Dispatcher.UIThread too.

WPF

this.Dispatcher.InvokeAsync(handler, DispatcherPriority.Background);

Avalonia

Dispatcher.UIThread.InvokeAsync(handler, DispatcherPriority.Background);

In more details, it's explained in the Accessing the UI thread article.

Visibility of elements

WPF has uses Visibility property which can be Collapsed, Hidden or Visible. Avalonia uses simpler and more intuitive model bool IsVisible.

Binding

WPF

<TextBox Name="MyTextbox" Text="{Binding ElementName=searchTextBox, Path=Text}"" />

Avalonia

<TextBox Name="MyTextbox" Text="{Binding #searchTextBox.Text}" />

Handling attachment to visual tree

There no events like Loaded/Unloaded in Avalonia, but you can override OnAttachedToVisualTree/OnDetachedFromVisualTree on the control, to know when control attached to virtual tree, or detatched from it. Alternatively you can use TemplateApplied instead of Loaded event.

WPF

Unloaded += OnControl_Unloaded;
Loaded += OnControl_Loaded;

private void OnControl_Loaded(object sender, RoutedEventArgs e)
{
    // Handle control loaded event.
}

private void OnControl_Unloaded(object sender, RoutedEventArgs e)
{
    // Handle control unload event.
}

Avalonia

TemplateApplied += OnControl_Loaded;
private void OnControl_Loaded(object sender, RoutedEventArgs e)
{

}
// or
protected override void OnAttachedToVisualTree(VisualTreeAttachmentEventArgs e)
{
    // Handle control loaded event.
}

// Use this instead of Unloaded event.
protected override void OnDetachedFromVisualTree(VisualTreeAttachmentEventArgs e)
{
    // Handle control unload event.
}

That mean that you cannot subscribe to tree attachment/detachment events for other controls.

Tooltips

Avalonia controls does not have ToolTip property like WPF. Instead you should use ToolTip.Tip

WPF

<Button ToolTip="Save file as..." />

Avalonia

<Button ToolTip.Tip="Save file as..." />

TextRun decorations

WPF

TextRunProperties.SetTextDecorations(TextDecorations.Underline);

Avalonia

TextRunProperties.Underline = true;