Avalonia/samples/ControlCatalog/Pages/DialogsPage.xaml

<UserControl x:Class="ControlCatalog.Pages.DialogsPage"
             xmlns="https://github.com/avaloniaui"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
  <StackPanel Margin="4"
              Orientation="Vertical"
              Spacing="4">

    <TextBlock Text="Windows:" />

    <Expander Header="Window dialogs">
      <StackPanel Spacing="4">
        <Button Name="DecoratedWindow">Decorated _window</Button>
        <Button Name="DecoratedWindowDialog">Decorated w_indow (dialog)</Button>
        <Button Name="Dialog" ToolTip.Tip="Shows a dialog">_Dialog</Button>
        <Button Name="DialogNoTaskbar">Dialog (_No taskbar icon)</Button>
        <Button Name="OwnedWindow">Own_ed window</Button>
        <Button Name="OwnedWindowNoTaskbar">Owned window (No tas_kbar icon)</Button>
      </StackPanel>
    </Expander>

    <TextBlock Margin="0,20,0,0" Text="Pickers:" />

    <CheckBox Name="UseFilters">Use filters</CheckBox>
    <Expander Header="FilePicker API">
      <StackPanel Spacing="4">
        <CheckBox Name="ForceManaged">Force managed dialog</CheckBox>
        <CheckBox Name="OpenMultiple">Open multiple</CheckBox>
        <Button Name="OpenFolderPicker">Select Fo_lder</Button>
        <Button Name="OpenFilePicker">_Open File</Button>
        <Button Name="SaveFilePicker">_Save File</Button>
        <Button Name="OpenFileFromBookmark">Open File Bookmark</Button>
        <Button Name="OpenFolderFromBookmark">Open Folder Bookmark</Button>
      </StackPanel>
    </Expander>
    <Expander Header="Legacy OpenFileDialog">
      <StackPanel Spacing="4">
        <Button Name="OpenFile">_Open File</Button>
        <Button Name="OpenMultipleFiles">Open _Multiple File</Button>
        <Button Name="SaveFile">_Save File</Button>
        <Button Name="SelectFolder">Select Fo_lder</Button>
        <Button Name="OpenBoth">Select _Both</Button>
      </StackPanel>
    </Expander>

    <TextBlock x:Name="PickerLastResultsVisible"
               Classes="h2"
               IsVisible="False"
               Text="Last picker results:" />
    <ItemsPresenter x:Name="PickerLastResults" />

    <TextBox Name="BookmarkContainer" Watermark="Bookmark" />
    <TextBox Name="OpenedFileContent"
             MaxLines="10"
             Watermark="Picked file content" />

  </StackPanel>
</UserControl>