Problem in calling function parameter as generics dictionary from C# to vb.net

Question

I have a function written in C# which has one parameter type as Dictionary<string , string>. When i try to call this function in VB.Net it doesn't show the type as Dictionary<string , string> it shows as string. Below is my function

public bool RegisterCustomerAttribute(int CustomerId
                                          , Dictionary<string , string> dictAttribute)
    {
        try
        {

            List<string> keys = new List<string>(dictAttribute.Keys);

            foreach (string key in keys)
            {
                CustomerAttribute custattr = new CustomerAttribute();

                custattr.Customer.CustomerID = CustomerId;
                custattr.Key = key;
                custattr.Value = dictAttribute[key];

                customerattrepo.AddCustomerAttribute(custattr);

            }

            return true;
        }
        catch (Exception ex)
        {
            string strMsg = ex.Message;
            return false;
        }
    }