CODEWITHSUNDEEP
c#.nettypes
André Haupt
André Haupt

Reputation: 3524

Generic type casting method (.Net)

I'm trying to create a generic method to cast an object, but can't seem to crack that chestnut. (It's Friday 3pm, been a long week)

Ok, so I have this scenario:

// We have a value (which .net sets as a double by default)
object obj = 1.0;

// We have the target type as a string, which could be anything:
// say string sometType = "System.Decimal"
Type type = Type.GetType(someType);

// I need a generic way of casting this
object castedObj = (xxx) obj;

How can I cast that object generically without creating an endless number of if-else-staments?

Upvotes: 12

Views: 9199

Answers (4)

Mark Coleman
Mark Coleman

Reputation: 40863

You can do something like the following:

    Type underlyingType = Type.GetType(someType);


    if (underlyingType.IsGenericType && underlyingType.GetGenericTypeDefinition().Equals(typeof (Nullable<>)))
    {
        var converter = new NullableConverter(underlyingType);
        underlyingType = converter.UnderlyingType;
    }

    // Try changing to Guid  
    if (underlyingType == typeof (Guid))
    {
        return new Guid(value.ToString());
    }
    return Convert.ChangeType(value, underlyingType);

Kudos to Monsters Go My.net for the change type function

Upvotes: 0

Pop Catalin
Pop Catalin

Reputation: 62940

You can use Convert.ChangeType method, if the types you use implement IConvertible (all primitive types do).

    Convert.ChangeType(value, targetType);

Upvotes: 18

pgb
pgb

Reputation: 25001

You can't cast it to a type you specify dynamically.

You may consider using generics instead, but I would need more code to see how it can help you.

Upvotes: 0

Jamie Ide
Jamie Ide

Reputation: 49261

Have a look at the Convert.ChangeType method, I think it will meet your needs.

Upvotes: 3

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