WPF and initial focus
I had the bright idea to dig through Reflector to see where the Focusable property is used, and found my way to this solution. I just need to add the following code to my Window's constructor:
Loaded += (sender, e) =>
MoveFocus(new TraversalRequest(FocusNavigationDirection.First));
This will automatically select the first control in the tab order, so it's a general solution that should be able to be dropped into any window and Just Work.
This works, too:
<Window FocusManager.FocusedElement="{Binding ElementName=SomeElement}">
<DataGrid x:Name="SomeElement">
...
</DataGrid>
</Window>
Based on the accepted answer implemented as an attached behavior:
using System.Windows;
using System.Windows.Controls;
using System.Windows.Input;
namespace UI.Behaviors
{
public static class FocusBehavior
{
public static readonly DependencyProperty FocusFirstProperty =
DependencyProperty.RegisterAttached(
"FocusFirst",
typeof(bool),
typeof(FocusBehavior),
new PropertyMetadata(false, OnFocusFirstPropertyChanged));
public static bool GetFocusFirst(Control control)
{
return (bool)control.GetValue(FocusFirstProperty);
}
public static void SetFocusFirst (Control control, bool value)
{
control.SetValue(FocusFirstProperty, value);
}
static void OnFocusFirstPropertyChanged(
DependencyObject obj, DependencyPropertyChangedEventArgs args)
{
Control control = obj as Control;
if (control == null || !(args.NewValue is bool))
{
return;
}
if ((bool)args.NewValue)
{
control.Loaded += (sender, e) =>
control.MoveFocus(new TraversalRequest(FocusNavigationDirection.Next));
}
}
}
}
Use it like this:
<Window xmlns:Behaviors="clr-namespace:UI.Behaviors"
Behaviors:FocusBehavior.FocusFirst="true">