Question

我有几个数据类，想要从列表中选择一个项目。我们想使用lambda表达式来实现。但是当select属性在基类中时，似乎没有按预期工作。基类

public class BaseData 
{
   public bool isSelected;
   public int distance;
}

派生类

public class PlayerData: BaseData 
{
   public string nickname
}

一些逻辑

public class SelectData 
{
   public PlayerData GetPlayer()
   {
       List<PlayerData> playerdata = new List<PlayerData>();
       // this list gets its data from a JSON file and is populated as expected.
       // now we want to select the player data for processing.

       PlayerData player = playerdata.Find(x => x.isSelected);

       // on this part we unexpected results, when i move the isSelected to the class PlayerData it works perfect but than it is not possible to write a generic extensions with these Data classes.
      return player;
  }
}

我们想要使用类似

的扩展名

public static int AddToDropDown<T>(this Dropdown dropdown,
                                       List<T> baseDataList,
                                       string displayText,
                                       string iconName,
                                       bool isSelected) where T : new() {
enter code here --- add to dropdown and add the item to PlayerData or ...
}

没有编译器错误......出了什么问题？

Answer 1

对我来说它运作正常：在这里看到这个例子，可能还有其他原因导致了这个问题：

public void Main()
{
  List<PlayerData> playerdata = new List<PlayerData>
  {
    new PlayerData
    {
       isSelected = true,
       distance = 3,
       nickname = "First",

    },
    new PlayerData
    {
        isSelected = true,
        distance = 3,
         nickname = "Second",
    },
    new PlayerData
    {
       isSelected = true,
       distance = 3,
       nickname = "Third",
    }
  };

  PlayerData player = playerdata.Find(x => x.isSelected);
  Console.WriteLine(player);

}
public class BaseData 
{
   public bool isSelected;
   public int distance;
}
public class PlayerData: BaseData 
{
   public string nickname;
   public override string ToString() { return this.nickname;}
}

结果是'First'，因为它是列表中的第一个玩家。

具有基类属性的Lambda表达式

1 个答案: