How to select text at entering to cell

I have a Grid, and when I'm walking by cells of it, I enter to cell, but whithout selecting text. It's annoying because, when I need to change a value, 开发者_如何学运维I need firstly use Backspace key.

What can I do to after entering to cell have selected content of that cell?

I would recommend the use of a behavior for this purpose. Below I have included a minimal implementation that provides the functionality I think you're looking for:

/// <summary>
/// <see cref="Behavior{T}"/> of <see cref="TextBox"/> for selecting all text when the text box is focused
/// </summary>
public class TextBoxSelectOnFocusBehavior : Behavior<TextBox>
{
    private void AssociatedObject_GotFocus(object sender, RoutedEventArgs e)
    {
        TextBox textBox = (sender as TextBox);

        if (textBox != null)
            textBox.SelectAll();
    }

    /// <summary>
    /// React to the behavior being attached to an object
    /// </summary>
    protected override void OnAttached()
    {
        base.OnAttached();

        AssociatedObject.GotFocus += AssociatedObject_GotFocus;
    }

    /// <summary>
    /// React to the behavior being detached from an object
    /// </summary>
    protected override void OnDetaching()
    {
        base.OnDetaching();

        AssociatedObject.GotFocus -= AssociatedObject_GotFocus;
    }
}

Hope this helps.