private ValueAccessorChangingEventArgs RaiseValueChanging(IDataContext context, object penultimateValue,
IBindingMemberInfo lastMember, object oldValue, object newValue)
{
var valueChanging = ValueChanging;
if (valueChanging == null)
return null;
var args = new ValueAccessorChangingEventArgs(context, penultimateValue, lastMember, oldValue, newValue);
valueChanging(this, args);
return args;
}
public void RaiseValueChanging(ValueAccessorChangingEventArgs e)
{
var handler = ValueChanging;
if (handler != null) handler(this, e);
}
private void SourceOnValueChanging(IBindingSourceAccessor sender, ValueAccessorChangingEventArgs args)
{
if (args.Cancel)
return;
object value = Binding.TargetAccessor.Source.GetPathMembers(false).PenultimateValue;
if (value != null && !value.IsUnsetValue())
args.Cancel = (bool)_member.GetValue(value, null);
}