List.AddRange有一些无效的参数

Question

我想创建一个符合预定义的IFlower接口的花的列表（例如），如下所示。

public interface IFlower 
{ 
    string colour { get; } 
    int petals { get; } 
} 

public class Rose : IFlower 
{ 
    public Rose() 
    { 
     string[] colours = new string[]{ "Pink", "Orange", "Red", "Crimson", "Cerise" }; 
     Random random = new Random(); 
     colour = colours[random.Next(0, 4)]; 
    } 

    public string colour { get; set; } 

    public int petals 
    { 
     get { return 8; } 
    } 
} 

public class Daisy : IFlower{ 
    public Daisy() 
    { 
     string[] colours = new string[]{ "White", "Yellow", "Purple" }; 
     Random random = new Random(); 
     colour = colours[random.Next(0, 2)]; 
    } 

    public string colour { get; set; } 

    public int petals 
    { 
     get { return 18; } 
    } 
} 

public class Flowers 
{ 
    public List<Daisy> Daisies 
    { 
     get 
     { 
      List<Daisy> items = new List<Daisy>(); 
      items.Add(new Daisy()); 
      items.Add(new Daisy()); 
      return items; 
     } 
    } 

    public List<Rose> Roses 
    { 
     get 
     { 
      List<Rose> items = new List<Rose>(); 
      items.Add(new Rose()); 
      items.Add(new Rose()); 
      return items; 
     } 
    } 
} 

问题是，当我运行下面的代码来创建拼接列表：

public List<IFlower> Flowers 
    { 
     get 
     { 
      List<IFlower> output = new List<IFlower>(); 
      output.AddRange(Daisies); 
      output.AddRange(Roses); 
      return output; 
     } 
    } 

我得到的错误：

The best overloaded method match for 'System.Collections.Generic.List<IFlower>.AddRange(System.Collections.Generic.IEnumerable<IFlower>)' has some invalid arguments 

Answer 1

玫瑰和雏菊令牌必须在每个指到一个类的实例

IEnumerable<IFlower> 

所以我猜想其中一个或两个指的是别的东西。