/// <summary>
/// Converts a value into an object of type targetType.
/// </summary>
/// <param name="value">The value produced by the binding source.</param>
/// <param name="targetType">The type of the binding target property.</param>
/// <param name="parameter">The converter parameter, used as default value.</param>
/// <param name="culture">The culture to use in the converter.</param>
/// <returns>
/// A converted value. If the method returns null, the valid null value is used.
/// Returns Binding.DoNothing for unsupported targetType
/// Returns DependencyProperty.UnsetValue if conversion fails.
/// </returns>
public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
if (targetType == typeof(bool))
{
return(ConvertToBool(value, parameter));
}
else if (targetType == typeof(bool?))
{
return(ConvertToNullableBool(value, parameter));
}
else if (typeof(IConvertible).IsAssignableFrom(targetType))
{
bool?boolValue = NullableBooleanConverter.ConvertToNullableBool(value, parameter);
try
{
return(System.Convert.ChangeType(boolValue, targetType, culture));
}
catch (InvalidCastException)
{
System.Diagnostics.Debug.WriteLine("{0}:ConvertBack failed '{1}' to '{2}', falling back to default '{3}'", this.GetType().Name, value, targetType, parameter);
if (parameter == null)
{
return(DependencyProperty.UnsetValue);
}
else
{
return(this.Convert(parameter, targetType, null, culture));
}
}
}
else
{
return(Binding.DoNothing);
}
}
/// <summary>
/// Converts a value with boolean representation to Visibility.
/// </summary>
/// <param name="value">The value produced by the binding source.</param>
/// <param name="targetType">The type of the binding target property. Only Visibility allowed.</param>
/// <param name="parameter">The Visibility used if value has no boolean representation.</param>
/// <param name="culture">This parameter is ignored.</param>
/// <returns>The value converted to Visibility.</returns>
public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
Debug.Assert(typeof(Visibility).IsAssignableFrom(targetType), this.GetType().Name + " Convert() supports only 'Visibility' as target type");
bool?result = NullableBooleanConverter.ConvertToNullableBool(value, null);
if (result != null && result.HasValue)
{
return(result.Value ? Visibility.Visible : InvisibleVisibility(ParseVisibility(parameter)));
}
else
{
return(ParseVisibility(parameter));
}
}
/// <summary>
/// Converts multiple values with boolean representation to Visibility.
/// </summary>
/// <param name="values">The values to convert</param>
/// <param name="targetType">The type of the binding target property. Only Visibility allowed.</param>
/// <param name="parameter">
/// A string specifying the operator used in this conversion and the default value for invalid boolean values. "'operator'(,'default value')"
/// Supported operators are: "AND", "OR", default is "AND,Hidden"</param>
/// <param name="culture">This parameter is ignored.</param>
/// <returns>The Visibility value calculated from values</returns>
public object Convert(object[] values, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
Debug.Assert(typeof(Visibility).IsAssignableFrom(targetType), "Only Visibility allowed as type of the binding target property");
Visibility defaultVisibility = ParseVisibility(parameter);
if (NullableBooleanConverter.Convert(values, defaultVisibility == Visibility.Visible, ParseOrOperator(parameter)))
{
return(Visibility.Visible);
}
else
{
return(InvisibleVisibility(ParseVisibility(parameter)));
}
}