How to call a method of type T passing T As string or "T"

Question

I have something like this

public void FunctionName<T>(){

}

and to call this you need something like this

sub main(){
    FunctionName<Integer>();
}

my question is can i pass the Integer as "Integer"?

sub main(){
    FunctionName<"Integer">();
}

or is there any other way to that

Ok here is my actual code

private static T Convert<T>(DataRow row) where T : new()
{
    T model = new T();
    Type modelType = model.GetType();
    FieldInfo[] fields = null;
    FieldInfo field = default(FieldInfo);
    Type fieldType = null;
    string fieldName = null;

    fields = modelType.GetFields(BindingFlags.Public | BindingFlags.Instance | BindingFlags.NonPublic | BindingFlags.Static);

    foreach ( field in fields) {
        fieldType = field.FieldType;
        fieldName = field.Name.Replace("_", string.Empty);
        Interaction.CallByName(model, fieldName, Microsoft.VisualBasic.CallType.Set, GetValue(row, fieldName, fieldType.Name));
    }

    return model;
}


static void main(){
    Student s;

    s = Convert<Student>(DatabaseRow);
}

The problem here is I just can only get the Student as string ("Student") from somewhere that will use this code Any other solution to get this right?

Are you sure you're programming in C#? Maybe you should change the tags of your question to include the actual language ('sub' sounds like VB) — Tipx, Aug 05 '12 at 16:19
sorry for sub stuff, yup i'm coding on C# and vb, maybe i should look it more first before posting it here, my mistake. — valrecx, Aug 05 '12 at 16:30

Kirk Woll · Accepted Answer · 2012-08-05T17:29:52.043

Without seeing more of your code, it's hard to say for sure whether you have a legitimate use-case for invoking a method like this. But regardless, assuming FunctionName is contained in class Foo, then you can invoke the method using reflection:

var foo = new Foo();
var typeName = "System.Int32";
var method = typeof(Foo).GetMethod("FunctionName");
var genericMethod = method.MakeGenericMethod(Type.GetType(typeName));
genericMethod.Invoke(foo, new Type[0]);

Note that we can't use Integer since that's not the real type name. (it's either int or Int32 in C# but only Int32 is legal for GetType since int is baked into the compiler) Also, all the usual caveats about getting a type via Type.GetType apply here (there are many situations where it won't find your custom type).

score 4 · Answer 2 · answered Aug 05 '12 at 16:10

4

No, you can't do that. You should use generics only if the type is known at compile-time. That's the whole point of generics: enforce compile-time safety. If the type is not known at compile-time, as in your case, you could use Reflection or some other technique depending on what you are trying to achieve.

answered Aug 05 '12 at 16:10

Darin Dimitrov

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Thats what I'm trying to do. Use Reflections to call the function but that technique returns the classname as string instead of the actual class type – valrecx Aug 05 '12 at 16:55

score 0 · Answer 3 · answered Aug 05 '12 at 16:17

0

In additin to Darin's answer: If the function was not compiled for the specified type (simply because it's never explicitely called for this type), the code is not available at all.

answered Aug 05 '12 at 16:17

Serge Wautier

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How to call a method of type T passing T As string or "T"

3 Answers3

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