メイン静的voidのクラスリストを表示

Question

私が作ったリストを出力するのを探していますが、通常はそれぞれのループに対してaを実行し、以下のコードのようにリストを呼び出します。コンソールはそれを修正することを望んでいますが、参照がnullのため表示されません。任意のヘルプ

class Program 
{ 
    const string FILENAME = @"royalTreeResults.xml"; 
    // THIS SECTION OF CODE IS WHAT IT SUGGESTS private static readonly IEnumerable<Family> families; 

    static void Main(string[] args) 
    { 
     XDocument doc = XDocument.Load(FILENAME); 
     Tree tree = new Tree(); 
     tree.families = doc.Descendants("family").Select(x => new Family() 
     { 
      FamilyName = (string)x.Element("name"), 
      FamilyTotalReign = (int)x.Element("totalReign"), 
      People = x.Elements("person").Select(y => Person.Recursive(y)).ToList() 
     }).ToList(); 
     foreach(Family per in families) // <--- THE ERROR IS HERE 
     { 
      Console.WriteLine(per.FamilyName + " " + per.FamilyTotalReign + " " + per.People); 
     } 
    } 
} 
public class Family 
{ 
    public string FamilyName { get; set; } 
    public int FamilyTotalReign { get; set; } 
    public List<Person> People { get; set; } 
} 
public class Person 
{ 
    public int? PersonBorn { get; set; } 
    public int? PersonCoronation { get; set; } 
    public int? PersonDied { get; set; } 
    public string PersonName { get; set; } 
    public int? PersonYinPower { get; set; } 
    public List<Person> Children { get; set; } 

    public static Person Recursive(XElement person) 
    { 
     Person newPerson = new Person(); 
     newPerson.PersonName = (string)person.Element("name"); 
     newPerson.PersonYinPower = (int?)person.Element("yearsInpower"); 
     newPerson.PersonBorn = (int?)person.Element("born"); 
     newPerson.PersonDied = (int?)person.Element("died"); 
     newPerson.PersonCoronation = (int?)person.Element("coronation"); 
     if (person.Element("children") != null) 
     { 
      newPerson.Children = person.Element("children").Elements("person").Select(y => Person.Recursive(y)).ToList(); 
     } 
     return newPerson; 
    } 
} 
public class Tree 
{ 
    public List<Family> families = new List<Family>(); 
} 

.xmlファイルのサンプルは以下であるため おかげで、しかし、私は、これが問題

<?xml version="1.0" encoding="utf-8"?> 
 
<royaltree> 
 
    <family> 
 
    <name>Wessex</name> 
 
    <totalReign>137</totalReign> 
 
    <person> 
 
     <name>Alfred the Great</name> 
 
     <yearsInpower>28</yearsInpower> 
 
     <born>849</born> 
 
     <died>899</died> 
 
     <coronation>871</coronation> 
 
     <children> 
 
     <person> 
 
      <name>Edward the Elder</name> 
 
      <yearsInpower>25</yearsInpower> 
 
      <born>879</born> 
 
      <died>924</died> 
 
      <coronation>899</coronation> 
 
      <children> 
 
      <person> 
 
       <name>Edmund I the Elder</name> 
 
       <yearsInpower>6</yearsInpower> 
 
       <born>939</born> 
 
       <died>946</died> 
 
       <coronation>940</coronation> 
 
       <children> 
 
       <person> 
 
        <name>Edger the Peaceful</name> 
 
        <yearsInpower>16</yearsInpower> 
 
        <born>944</born> 
 
        <died>975</died> 
 
        <coronation>959</coronation> 
 
        <children> 
 
        <person> 
 
         <name>Ethelred II</name> 
 
         <yearsInpower>38</yearsInpower> 
 
         <born>962</born> 
 
         <died>1016</died> 
 
         <coronation>978</coronation> 
 
         <children> 
 
         <person> 
 
          <name>Edward Confessor</name> 
 
          <yearsInpower>24</yearsInpower> 
 
          <born>1002</born> 
 
          <died>1066</died> 
 
          <coronation>1042</coronation> 
 
         </person> 
 
         <person> 
 
          <name>Edward II Ironside</name> 
 
          <yearsInpower>0</yearsInpower> 
 
          <born>1002</born> 
 
          <died>1016</died> 
 
          <coronation>1016</coronation> 
 
         </person> 
 
         </children> 
 
        </person> 
 
        </children> 
 
       </person> 
 
       </children> 
 
      </person> 
 
      </children> 
 
     </person> 
 
     </children> 
 
    </person> 
 
    </family> 
 
    <family> 
 
    <name>Norman</name> 
 
    <totalReign>69</totalReign> 
 
    <person> 
 
     <name>William I</name> 
 
     <yearsInpower>21</yearsInpower> 
 
     <born>1028</born> 
 
     <died>1087</died> 
 
     <coronation>1066</coronation> 
 
     <children> 
 
     <person> 
 
      <name>Adela</name> 
 
      <born>1050</born> 
 
      <died>1080</died> 
 
     </person> 
 
     <person> 
 
      <name>William II</name> 
 
      <yearsInpower>13</yearsInpower> 
 
      <born>1056</born> 
 
      <died>1100</died> 
 
      <coronation>1087</coronation> 
 
     </person> 
 
     <person> 
 
      <name>Henry I Beauclerc</name> 
 
      <yearsInpower>35</yearsInpower> 
 
      <born>1068</born> 
 
      <died>1135</died> 
 
      <coronation>1100</coronation> 
 
      <children> 
 
      <person> 
 
       <name>Matilda</name> 
 
       <born>1130</born> 
 
       <died>1167</died> 
 
      </person> 
 
      </children> 
 
     </person> 
 
     </children> 
 
    </person> 
 
    </family>

Answer 1

私が得れば私にはわからないではありません知っていますその通り。しかし、これが役立つといいですね。

static void Main(string[] args) 
{ 
    //... your stuff 

    //Iterate through families in tree 
    foreach (Family per in tree.families) 
    { 
     //Show the family info 
     Console.WriteLine(per.FamilyName + " " + per.FamilyTotalReign); 

     //Show the members recursively 
     ShowPeopleRecursive(per.People, 1); 
    } 
} 

//Shows the people tree. 
private static void ShowPeopleRecursive(List<Person> people, int level) 
{ 
    const string indent = ""; 
    foreach (var p in people) 
    { 
     Console.WriteLine($"{indent.PadLeft(level, ' ')} {p.PersonName} ({p.PersonBorn} - {p.PersonDied}). Years in power: {p.PersonYinPower}"); 

     if (p.Children != null) 
      ShowPeopleRecursive(p.Children, level + 1); 
    } 
} 

あなたは、あなたの家族の上をツリーで繰り返して、その人とその子供たちを再帰的に印刷します。

・ホープ、このことができます：あなたは次のように表示されるはずです！

Answer 2

このように、以下のように人のリストをループする必要があります。

foreach (Family per in tree.families) // <--- THE ERROR IS HERE 
{ 
      Console.WriteLine(per.FamilyName + " " + per.FamilyTotalReign); 
      foreach (var ppl in per.People) 
      { 
       Console.WriteLine(ppl.PersonName + " " + per.FamilyName); 
      } 
} 

しかし、私はXmlSerializerをを使用するためにあなたをお勧めしたいと思い、あなたがobject.ThisにあなたのXMLをデシリアライズすることができますがはるかにきれいなアプローチです。サンプルコードを知りたい場合は、