Question

I have code similar to this:

class Foo {        Dictionary<Type, Object> _dict;    void Create(string myType, string myValue)   {     var instance = Type.Instanciate(myType)  // How do I do this?     if (var.IsPrimitive)     {       var.GetType().Parse(myValue)   // I know this is there...how to invoke?       Dictionary[instance.GetType()] = instance;     }   }    T GetValue<T>(T myType) { return (T)_dict[T]; } }  // Populate with values foo.Create('System.Int32', '15'); foo.Create('System.String', 'My String'); foo.Create('System.Boolean', 'False');  // Access a value bool b = GetValue(b); 

So my questions are:
a) How do I instantiate the type
b) Parse the type value from a string when Parse is supported.

Answer 1

• Getting a type: Type.GetType()
• Instantiating a type from a Type object: Activator.CreateInstance (You don’t actually need this in your code.)
• Converting from a string: Convert.ChangeType

Note that if the type isn’t in mscorlib or the currently executing assembly, you’ll need to include the assembly name (and version information if it’s strongly named).

Here’s a complete example using your original code. Note that GetValue doesn’t need a normal parameter, as you’ve already given the type parameter (T).

using System; using System.Collections.Generic;  public class Foo {        Dictionary<Type, Object> _dict = new Dictionary<Type, Object>();    public void Create(string myType, string myValue)   {       Type type = Type.GetType(myType);       object value = Convert.ChangeType(myValue, type);       _dict[type] = value;   }    public T GetValue<T>() { return (T)_dict[typeof(T)]; } }   class Test {     static void Main()     {         Foo foo = new Foo();          // Populate with values         foo.Create('System.Int32', '15');         foo.Create('System.String', 'My String');         foo.Create('System.Boolean', 'False');          Console.WriteLine(foo.GetValue<int>());         Console.WriteLine(foo.GetValue<string>());         Console.WriteLine(foo.GetValue<bool>());     } }