让Dictionary key 支持自定义对象

让Dictionary key 支持自定义对象，则对象必须继承IEquatable，重写GetHashCode、Equals

 

class Foo : IEquatable<Foo> { 
    public string Name { get; set;} 
    public int FooID {get; set;} 
 
    public override int GetHashCode() { 
        return Name.GetHashCode()+FooID.GetHashCode(); 
    } 
    public override bool Equals(object obj) { 
        return Equals(obj as Foo); 
    } 
    public bool Equals(Foo obj) { 
        return obj != null && obj.FooID == this.FooID; 
    } 
}