/// <summary>
/// Event handler for Textbox on preview text. Called before displaying the entered text.
/// </summary>
/// <param name="e"></param>
protected override void OnPreviewTextInput(System.Windows.Input.TextCompositionEventArgs e)
{
if (IsReadOnly)
{
base.OnPreviewTextInput(e);
return;
}
if (Mask != null)
{
if (IsValid(e.Text))
{
int position = SelectionStart;
MaskTextFormatter maskProvider = MaskProvider;
if (position < maskProvider.Capacity)
{
position = maskProvider.InsertAt(e.Text, position);
}
RefreshText(maskProvider, position);
}
e.Handled = true;
}
base.OnPreviewTextInput(e);
}
/// <summary>
/// Use the mask to generate a new display string.
/// </summary>
/// <param name="maskProvider"></param>
/// <param name="position"></param>
private void RefreshText(MaskTextFormatter maskProvider, int position)
{
// Refresh string.
this.Text = maskProvider.ToString();
// Position cursor.
this.SelectionStart = position;
}
/// <summary>
/// Handler for special keys like delete.
/// </summary>
/// <param name="e"></param>
protected override void OnPreviewKeyDown(KeyEventArgs e)
{
base.OnPreviewKeyDown(e);
MaskTextFormatter maskProvider = MaskProvider;
int position = SelectionStart;
int length = SelectionLength;
bool refresh = false;
if (e.Key == Key.Delete && position < Text.Length)
{
if (length > 0)
{
refresh = maskProvider.Remove(position, length);
}
else
{
refresh = maskProvider.Remove(position);
}
e.Handled = true;
}
else if (e.Key == Key.Back)
{
if (length > 0)
{
refresh = maskProvider.Remove(position, length);
}
else
{
if (position > 0)
{
position--;
refresh = maskProvider.Remove(position);
}
}
e.Handled = true;
}
else if (e.Key == Key.Escape)
{
this.maskTextFormatter.Set(((MaskTextBox)e.OriginalSource).Text);
}
if (refresh == true)
{
RefreshText(maskProvider, position);
}
}
/// <summary>
///Force the text of the control to use the mask
/// </summary>
/// <param name="sender"></param>
/// <param name="value"></param>
/// <returns></returns>
private static object ForceText(DependencyObject sender, object value)
{
MaskTextBox textBox = (MaskTextBox)sender;
if (textBox.Mask != null && value != null)
{
MaskTextFormatter provider = new MaskTextFormatter(textBox.Mask);
provider.Validate += delegate(char character)
{ return(textBox.IsValid(character)); };
provider.Set((string)value);
return(provider.ToString());
}
else
{
return(value);
}
}
