Using enum in ConverterParameter

Leonid picture Leonid · Feb 9, 2011 · Viewed 26k times · Source

I am building an application that can be used by many users. Each user is classified to one of the next Authentication levels:

public enum AuthenticationEnum
{
    User,
    Technitian,     
    Administrator,
    Developer
}

Some controls (such as buttons) are exposed only to certain levels of users. I have a property that holds the authentication level of the current user:

public AuthenticationEnum CurrentAuthenticationLevel { get; set; }

I want to bind this property to the 'Visibilty' property of some controls and pass a parameter to the Converter method, telling it what is the lowest authentication level that is able to see the control. For example:

<Button Visibility="{Binding Path=CurrentAuthenticationLevel, Converter={StaticResource AuthenticationToVisibility}, ConverterParameter="Administrator"}"/>

means that only 'Administrator' and 'Developer' can see the button. Unfortunately, the above code passes "Administrator" as a string. Of course I can user Switch-Case inside the converter method and convert the string to AuthenticationEnum. But this is ugly and prone to maintenance errors (each time the enum changes - the converter method should change).

Is there a better way to pass not trivial object as a parameter?

Answer

Fredrik Hedblad picture Fredrik Hedblad · Feb 9, 2011

ArsenMkrt's answer is correct,

Another way of doing this is to use the x:Static syntax in the ConverterParameter

<Button ...
        Visibility="{Binding Path=CurrentAuthenticationLevel,
            Converter={StaticResource AuthenticationToVisibility},
            ConverterParameter={x:Static local:AuthenticationEnum.Administrator}}"/>

And in the converter

public class AuthenticationToVisibility : IValueConverter
{
    public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
    {
        AuthenticationEnum authenticationEnum = (AuthenticationEnum)parameter;
        //...
    }
}