CODEWITHSUNDEEP
c#.netc#-4.0asp.net-4.5
Lee Atkinson
Lee Atkinson

Reputation: 2179

Cast Object to MyType<T> where T can be any type

I have some code that searches for all types of type MyType<T> in an assembly. T can be any type I use Activator.CreateInstance to create objects of these types. I need to pass these objects into a method that is expecting MyType<T> so I need to somehow cast each object from Object (returned by Activator.CreateInstance) to something of MyType<T>.

Upvotes: 1

Views: 753

Answers (1)

user287107
user287107

Reputation: 9417

what you need is a combination of GetGenericTypeDefinition - MakeGenericType combination to form your own new type. here is an example:

    public class  GenericTypeTest<T>
    {
        T value;
    }

    void MakeTest()
    {
        var newType = typeof(double);
        var customType = typeof(GenericTypeTest<object>).GetGenericTypeDefinition().MakeGenericType(newType);
        var createdObject = Activator.CreateInstance(customType);
    }

if you want to use that createdObject, it is a little complicated because you can't "hard code" anything:

    public class  GenericTypeTest<T>
    {
        public GenericTypeTest(T value)
        {
            this.value = value;
        }
        public T value {get; protected set; }
    }

    public void ShowSomething<T>(GenericTypeTest<T> genericContainer)
    {
         MessageBox.Show(genericContainer.value.ToString());
    }

    void MakeTest()
    {
        var newType = typeof(double); object newValue = 1.0;

        var customType = typeof(GenericTypeTest<object>).GetGenericTypeDefinition().MakeGenericType(newType);
        var createdObject = Activator.CreateInstance(customType, newValue);

        this.GetType().GetMethod("ShowSomething").MakeGenericMethod(newType).Invoke(this, new object[] { createdObject });
    }

Upvotes: 1

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