删除"if"语句时出现问题

Question

嗨,

我正试图找到如何改进此代码的方法.我想从CreateAttributes方法中删除"if"语句.如果此属性满足某些条件,则此方法的主要思想是将属性添加到列表

  internal class FildMap
  {
    public string ExactTargetFild { get; set; }
    public string DbFild { get; set; }     
    public Type Type { get; set; }
  }

  internal static class FildMapProcessor
  {
    private static readonly List<FildMap> Map = new List<FildMap>();

    static FildMapProcessor()
    {
      if(Map.Count == 0)
      {
      Map.Add(new FildMap {ExactTargetFild = "Address 1", DbFild = "Address1", Type = typeof (string)});
      Map.Add(new FildMap { ExactTargetFild = "Date of birth", DbFild = "DateOfBirth", Type = typeof(DateTime) });
      Map.Add(new FildMap { ExactTargetFild = "Wine Beer", DbFild = "pref_WineBeerSpirits", Type = typeof(bool) });
      .........
      }
    }

    public static Attribute[] CreateAttributes(this DataRow row)
    {
      var attributes = new List<Attribute>();
      foreach (var item in Map)
      {
        if (item.Type == typeof(string))
        {
          var value = row.Get<string>(item.DbFild);
          if (value != null)
            attributes.Add(new Attribute{Name = item.ExactTargetFild, Value = value});
        }

        if (item.Type == typeof(DateTime))
        {
          var value = row.Get<DateTime>(item.DbFild);
          if (value != DateTime.MinValue)
            attributes.Add(new Attribute { Name = item.ExactTargetFild, Value = value.ToString("dd/MM/yyyy") });
        }

        if (item.Type == typeof(bool))
        {
          if (row.Contains(item.DbFild))
          {
            var value = row.Get<bool>(item.DbFild);
            attributes.Add(new Attribute { Name = item.ExactTargetFild, Value = value.ToString() });
          }
        }
      }

      return attributes.ToArray();
    }
  }

谢谢,

Answer 1

你可以在这里使用多态

  internal abstract class FildMap
  {
    public string ExactTargetFild { get; set; }
    public string DbFild { get; set; }     
    public abstract List<Attributes> GetAttributes(DataRow row);
  }

  internal class StringFildMap : FildMap
  { 
    public override List<Attributes> GetAttributes(DataRow row)
    {
      //string specific stuff
    }
  }

为其他类型创建其他类

public static Attribute[] CreateAttributes(this DataRow row)
{
  var attributes = new List<Attribute>();
  foreach (var item in Map)
  {
    attributes.AddRange(item.GetAttributes(row)); 
  }

  return attributes.ToArray();
}