Avalonia/samples/ControlCatalog/Pages/AutoCompleteBoxPage.xaml

<UserControl x:Class="ControlCatalog.Pages.AutoCompleteBoxPage"
             xmlns="https://github.com/avaloniaui"
             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:sys="clr-namespace:System;assembly=netstandard"
             d:DesignHeight="600"
             d:DesignWidth="400">
  <StackPanel Orientation="Vertical"
              Spacing="4"
              MaxWidth="660">
    <TextBlock Classes="h2">A control into which the user can input text</TextBlock>

    <UniformGrid Margin="-8,0"
                 Columns="2">
      <UniformGrid.Styles>
        <Style Selector="StackPanel">
          <Setter Property="Margin" Value="8" />
        </Style>
      </UniformGrid.Styles>
      <StackPanel>
        <TextBlock Text="MinimumPrefixLength: 1" />
        <AutoCompleteBox MinimumPrefixLength="1" />
      </StackPanel>
      <StackPanel>
        <TextBlock Text="MinimumPrefixLength: 3" />
        <AutoCompleteBox MinimumPrefixLength="3" />
      </StackPanel>
      <StackPanel>
        <TextBlock Text="MinimumPopulateDelay: 1s" />
        <AutoCompleteBox MinimumPopulateDelay="1" />
      </StackPanel>
      <StackPanel>
        <TextBlock Text="MaxDropDownHeight: 60" />
        <AutoCompleteBox MaxDropDownHeight="60" />
      </StackPanel>
      <StackPanel>
        <TextBlock Text="Watermark" />
        <AutoCompleteBox Watermark="Hello World" />
      </StackPanel>
      <StackPanel>
        <TextBlock Text="Disabled" />
        <AutoCompleteBox IsEnabled="False" />
      </StackPanel>

      <StackPanel>
        <TextBlock Text="ValueMemberBinding" />
        <AutoCompleteBox ValueMemberBinding="{Binding Capital}" />
      </StackPanel>
      <StackPanel>
        <TextBlock Text="Multi-Binding" />
        <AutoCompleteBox Name="MultiBindingBox" FilterMode="Contains" />
      </StackPanel>
      <StackPanel>
        <TextBlock Text="Async Populate" />
        <AutoCompleteBox Name="AsyncBox" FilterMode="None" />
      </StackPanel>
      <StackPanel>
        <TextBlock Text="Custom Autocomplete" />
        <AutoCompleteBox Name="CustomAutocompleteBox" FilterMode="None" />
      </StackPanel>
    </UniformGrid>
    <StackPanel>
      <TextBlock Text="With Validation Errors" />
      <AutoCompleteBox Name="ValidationErrors" FilterMode="None">
        <DataValidationErrors.Error>
          <sys:Exception />
        </DataValidationErrors.Error>
      </AutoCompleteBox>
    </StackPanel>
  </StackPanel>
</UserControl>