Focus on EditorSeachView

using System.Windows;
using System.Windows.Input;

namespace ActiproTest
{
  public partial class MainWindow : Window
  {
    public static RoutedUICommand FindCommand = new RoutedUICommand(
      "Find",
      "Find",
      typeof(MainWindow),
      new InputGestureCollection(new KeyGesture[] { new KeyGesture(Key.F, ModifierKeys.Control, "F") }));

    public MainWindow()
    {
      InitializeComponent();
    }
    private void OnFind(object sender, RoutedEventArgs e)
    {
      if (search.IsVisible)
      {
        search.Visibility = System.Windows.Visibility.Collapsed;
      }
      else
      {
        search.Visibility = System.Windows.Visibility.Visible;
        search.Focus();
      }
      e.Handled = true;
    }
  }
}

<Window 
  x:Class="ActiproTest.MainWindow"
  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
  xmlns:acti="http://schemas.actiprosoftware.com/winfx/xaml/syntaxeditor"
  xmlns:local="clr-namespace:ActiproTest"
  Title="MainWindow" Height="350" Width="525">
  <Window.CommandBindings>
    <CommandBinding Command="local:MainWindow.FindCommand" Executed="OnFind"/>
  </Window.CommandBindings>
  <DockPanel LastChildFill="True">
    <Button 
      Command="local:MainWindow.FindCommand"
      Width="16" 
      DockPanel.Dock="Right"></Button>
    <acti:EditorSearchView 
      x:Name="search"
      DockPanel.Dock="Right"/>
    <acti:SyntaxEditor/>
  </DockPanel>
</Window>