CODEWITHSUNDEEP
c#.netnullable
Maciej Wozniak
Maciej Wozniak

Reputation: 1174

Conversion between Nullable types

Is there a converter in .NET 4.0 that supports conversions between nullable types to shorten instructions like:

bool? nullableBool = GetSomething();
byte? nbyte = nullableBool.HasValue ? (byte?)Convert.ToByte(nullableBool.Value) : null;

Upvotes: 7

Views: 7477

Answers (2)

Darin Dimitrov
Darin Dimitrov

Reputation: 1039368

I would write an extension method:

public static class Extensions
{
    public static TDest? ConvertTo<TSource, TDest>(this TSource? source) 
        where TDest: struct 
        where TSource: struct
    {
        if (source == null)
        {
            return null;
        }
        return (TDest)Convert.ChangeType(source.Value, typeof(TDest));
    }
}

and then:

bool? nullableBool = true;
byte? nbyte = nullableBool.ConvertTo<bool, byte>();

Upvotes: 6

Daniel Hilgarth
Daniel Hilgarth

Reputation: 174447

Not that I am aware of.
You could just write a helper method like this:

public Nullable<TTarget> NullableConvert<TSource, TTarget>(
          Nullable<TSource> source, Func<TSource, TTarget> converter)
    where TTarget: struct
    where TSource: struct
{
    return source.HasValue ? 
               (Nullable<TTarget>)converter(source.Value) : 
               null;
}

Call it like this:

byte? nbyte = NullableConvert(nullableBool, Convert.ToByte);

Upvotes: 4

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