如何从主类循环子类属性

public class GroupA
{
  public string FullName = "", BirthDay = "";
}
public class GroupB
{
  public string Email = "";
}
public class GroupC
{
  public string Phone;
}
public class MainGroup
{
  public GroupA GroupA;
  public GroupB GroupB;
  public GroupC GroupC;
}

    protected void Page_Load(object sender, EventArgs e)
    {
      GroupA  NewGroupA = new GroupA();
              NewGroupA.FullName="TEST MASTER";
              NewGroupA.BirthDay="02/20/1984";
      GroupB  NewGroupB = new GroupB();
              NewGroupB.Email="noreply@test.com"; 
      GroupC  NewGroupC=new GroupC();
              NewGroupC.Phone="555 123 4567";
      //Assign new class instances to the main class
      MainGroup NewMainGroup= new MainGroup();
                NewMainGroup.GroupA=NewGroupA;
                NewMainGroup.GroupB=NewGroupB;                 
                NewMainGroup.GroupC=NewGroupC;
      //Loop through the main class
      foreach (var Group in typeof(MainGroup).GetFields())
      {
        Response.Write("<BR>MainGroupName=  " + Group.Name + " Value=  " + Group.GetValue(NewMainGroup).ToString());
        //PROBLEM IS HERE. Can't loop through the subclass We need to display the GroupA, GroupB, GroupC below.
        foreach (var SubGroup in Group)
        {
          Response.Write("<BR>");
        }

      }
}

如果我理解你的问题，我认为这段代码就是你的答案：

foreach (var group in NewMainGroup.GetType().GetFields())
{
    var groupInstance = group.GetValue(NewMainGroup);
    foreach (var subGroup in groupInstance.GetType().GetFields())
    {
        Response.Write("<br />" + subGroup.Name + " = " + subGroup.GetValue(groupInstance));
    }
}

您应该存储对组变量（而不仅仅是类型）的引用。所以，如果你拿着你的代码做这样的事情：

foreach (var GroupType in typeof(MainGroup).GetFields())
{
    object Group = GroupType.GetValue(NewMainGroup);
    Response.Write("<BR>MainGroupName=  " + GroupType.Name + " Value=  " + Group.ToString());
    foreach(var SubGroupType in Group.GetType().GetFields()) {
        object SubGroup = SubGroupType.GetValue(Group);
        Response.Write("<BR>SubGroupName= " + SubGroupType.Name + " Value= " + SubGroup.ToString());
    }
}

我还没有测试过，但我认为这应该是关于工作的。至少让你开始吧。

哦，顺便说一句，我想我有一个更好的方法给你，试试这个：

public Dictionary<string, object> GetObjectFields(object obj) {
    var dict = new Dictionary<string, object>();
    var t = obj.GetType();
    foreach(var f in t.GetFields()) {
        dict[f.Name] = f.GetValue(obj);
    }
    return dict;
}

然后你可以简单地这样做：

var groupVars = GetObjectFields(NewMainGroup);
foreach(var gv in groupVars) {
    Response.Write(<BR>MainGroupName=  " + gv.Key + " Value=  " + gv.Value.ToString());
    var subGroupVars = GetObjectFields(gv.Value);
    foreach(var sgv in subGroupVars) {
        Response.Write(<BR>SubGroupName=  " + sgv.Key + " Value=  " + sgv.Value.ToString());
    }
}

首先，GroupA、GroupB和GroupC不是MainGroup的子类。您正在使用组合，并且具有GroupA、GroupB和GroupC类型的成员。

当你已经知道自己的类型时，不知道为什么要重新映射类型。你可以使用MainGroup.GroupA.Name等等。你发布的代码可能只是一个例子吗？

以下方法应反映基本结构并适合您的目的。

        static String Reflect(Object data)
        {
            StringBuilder stringBuilder = new StringBuilder();
            foreach (PropertyInfo propertyInfo in data.GetType().GetProperties())
            {
                if (propertyInfo.PropertyType.IsClass && propertyInfo.PropertyType != typeof(String))
                {
                    stringBuilder.AppendFormat("{0} : {1} {2}", propertyInfo.Name, Environment.NewLine 
                        , Reflect(propertyInfo.GetValue(data, null)));
                }
                else
                {
                   stringBuilder.AppendFormat("{0} = {1}, {2}", propertyInfo.Name,  propertyInfo.GetValue(data, null), Environment.NewLine);
                }
            }
            return stringBuilder.ToString();
        }

用法：

            MainGroup main = new MainGroup
            {
                A = new GroupA { Name = "GroupA", ID = 1 },
                B = new GroupB { Date = DateTime.UtcNow },
                C = new GroupC { HasData = false }
            };
            Reflect(main);