Semi.Avalonia/demo/Semi.Avalonia.Demo/Pages/DataValidationErrorsDemo.axaml

<UserControl
    x:Class="Semi.Avalonia.Demo.Pages.DataValidationErrorsDemo"
    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:system="clr-namespace:System;assembly=netstandard"
    d:DesignHeight="450"
    d:DesignWidth="800"
    mc:Ignorable="d">
    <StackPanel HorizontalAlignment="Left">
        <AutoCompleteBox Width="300">
            <DataValidationErrors.Error>
                <system:Exception />
            </DataValidationErrors.Error>
        </AutoCompleteBox>
        <ButtonSpinner Width="300">
            <DataValidationErrors.Error>
                <system:Exception />
            </DataValidationErrors.Error>
        </ButtonSpinner>
        <CalendarDatePicker Width="300">
            <DataValidationErrors.Error>
                <system:Exception />
            </DataValidationErrors.Error>
        </CalendarDatePicker>
        <ComboBox Width="300">
            <DataValidationErrors.Error>
                <system:Exception />
            </DataValidationErrors.Error>
        </ComboBox>
        <DatePicker Width="300">
            <DataValidationErrors.Error>
                <system:Exception />
            </DataValidationErrors.Error>
        </DatePicker>
        <NumericUpDown Width="300">
            <DataValidationErrors.Error>
                <system:Exception />
            </DataValidationErrors.Error>
        </NumericUpDown>
        <Slider Width="300">
            <DataValidationErrors.Error>
                <system:Exception />
            </DataValidationErrors.Error>
        </Slider>
        <TimePicker Width="300">
            <DataValidationErrors.Error>
                <system:Exception />
            </DataValidationErrors.Error>
        </TimePicker>
        <TextBox
            Width="300"
            InnerLeftContent="http://"
            InnerRightContent=".com">
            <DataValidationErrors.Error>
                <system:Exception />
            </DataValidationErrors.Error>
        </TextBox>
    </StackPanel>
</UserControl>