public void FocusNextTextBox(bool reverse = false)
{
var textBoxes = VisualTreeHelperEx.GetChildren(mUnitPriceItemsControl, true)
.OfType <TextBox>()
.Where(textbox => !textbox.IsReadOnly && textbox.IsEnabled);
if (reverse)
{
textBoxes = textBoxes.Reverse();
}
TextBox first = null;
var lastTextBoxIsFocused = false;
var focusChanged = false;
foreach (var textBox in textBoxes)
{
if (first == null)
{
first = textBox;
}
if (lastTextBoxIsFocused)
{
textBox.Focus();
focusChanged = true;
break;
}
else
{
lastTextBoxIsFocused = ReferenceEquals(FocusManager.GetFocusedElement(), textBox);
}
}
if (!focusChanged && first != null)
{
first.Focus();
}
}