How to create properties and collections at run time?

Provide some code. where you want to do this? At what stage you are now?

Meanwhile,

You can add properties dynamically in two ways,

1. using ExpandoObject

   var dynamicObject = new ExpandoObject();
   dynamicObject.YourPro1 = "Your Value 1";
   dynamicObject.YourPro1 = 1234;

2. using Dictionary

    public class MyClass
   {
       public string Template { get; set; }
       public string Term { get; set; }
       public Dictionary Properties{ get; private set; }

      public MyClass()
      {
          Properties= new Dictionary();
      }

      public void AddProperty(string key, string value)
      {
             Properties.Add(key, value);
      }
   }

    // to be used like this:
    MyClass instance = new MyClass();
    instance.AddProperty("Email", "[email protected]");
    instance.AddProperty("Phone", "976856734");

3. using Reflection Emit

    Please read here with Example.