Auto Suggest ComboBox - MVVM - wpf

Question

When I add to combobox the property IsEditable="True" it automatically receive the "Auto Complete" behavior.
Is there a way to add to this combobox the "Auto Suggest" behavior?
I mean, when writing in the combobox opens a list of options with the above caption.
(If possible = without destroying the MVVM)

Answer 1

Here you go
I tried to add the auto suggest kind of behavior using standard combobox and animation
<ComboBox IsEditable="True">
<ComboBoxItem>Orange</ComboBoxItem>
<ComboBoxItem>Apple</ComboBoxItem>
<ComboBoxItem>Banana</ComboBoxItem>
<ComboBoxItem>Cherry</ComboBoxItem>
<ComboBox.Triggers>
<EventTrigger RoutedEvent="TextBoxBase.TextChanged">
<BeginStoryboard>
<Storyboard>
<BooleanAnimationUsingKeyFrames Storyboard.TargetProperty="IsDropDownOpen">
<DiscreteBooleanKeyFrame Value="True" KeyTime="0:0:0"/>
</BooleanAnimationUsingKeyFrames>
</Storyboard>
</BeginStoryboard>
</EventTrigger>
</ComboBox.Triggers>
</ComboBox>
Give this a try and let me know if this is what you are looking for, more sophisticated behavior might need some extra efforts
Add suggestion filter for combo Items
xaml
<ComboBox IsEditable="True"
ItemsSource="{Binding ComboItems}"
Text="{Binding ComboText,Mode=OneWayToSource}">
<ComboBox.Triggers>
<EventTrigger RoutedEvent="TextBoxBase.TextChanged">
<BeginStoryboard>
<Storyboard>
<BooleanAnimationUsingKeyFrames Storyboard.TargetProperty="IsDropDownOpen">
<DiscreteBooleanKeyFrame Value="True"
KeyTime="0:0:0" />
</BooleanAnimationUsingKeyFrames>
</Storyboard>
</BeginStoryboard>
</EventTrigger>
</ComboBox.Triggers>
</ComboBox>
view model
public ICollectionView ComboItems{ get; set; }
public string ComboText
{
get
{
throw new NotImplementedException();
}
set
{
ComboItems.Filter = item => item.ToString().ToLower().Contains(value.ToLower());
}
}
you may need to filter based on your items types, above is for string values
to init the ComboItems
var myItems = new[] { "Apple", "Orange", "Cherry", "Banana" };
ComboItems = CollectionViewSource.GetDefaultView(myItems);
replace my items with your collection