确定列表中的嵌套对象属性是否相等。

Question

我有两个班，物业和经理。

public class Property
{
    public Manager Manager {get;set;}
}

public class Manager {
    public int ID { get; set; }
    public string Fullname {get; set;}
}

Property p1 = new  Property{
    Manager = new Manager {
        ID = 1,
        Fullname = "John  Doe"
    }
}

Property p2 = new  Property{
    Manager = new Manager {
        ID = 1,
        Fullname = "John  Doe"
    }
}

Property p3 = new  Property{
    Manager = new Manager {
        ID = 2,
        Fullname = "John  Doe"
    }
}

List<Property> properties = new List{ p1, p2, p3 }

在这个 List 的 properties我如何确定每个物业都有相同的管理人？ID? 如果一个或多个没有，那么我想返回 false.

Answer 1

你可以使用一点 System.Linq 以确定 All 项目具有相同 Id 作为 First 项。

bool allHaveSameId = properties.All(p => p.Manager.ID == properties.First().Manager.ID);

Answer 2

你只需覆盖属性和经理人的Equals就可以了

public class Manager{
    public int ID { get; set; }
    public string Fullname {get; set;}

    public override bool Equals(Manager that){
        if ((obj == null) || ! this.GetType().Equals(obj.GetType())){
            return false;
        }else {
            return this.ID == that.ID;
        }
    }
}

public class Property{
    public Manager Manager {get;set;}

    public override bool Equals(Property that){
        if ((obj == null) || ! this.GetType().Equals(obj.GetType())){
            return false;
        }else {
            return this.manager.Equals(that.Manager);
        }
    }
}

Answer 3

我想我会选择评论里链接的那种东西。

  return properties.Any() && properties.All(p=>p.Manager.ID == properties[0].Manager.Id);

Answer 4

return properties.Select(p => p.Manager.ID).Distinct().Count() == 1;