学步园

很多时候，我们需要将对象序列化成字符串保存到内存、磁盘或者 Page.ViewState 中。基于种种原因，我们希望序列化结果尽可能小，尽可能简单，即便用其他的方法(比如正则表达式)也能解析出数据。BinaryFormatter 的结果转换成字符串(或者Base64)长度太大，而 XmlSerializer 对数据类型支持有限，显然内置的序列化引擎不足以满足我们的需求，还是自己丰衣足食。

下面的代码可能还不完善，仅供参考，内容比较简单，不做详述。

/// <summary>
/// 序列化
/// </summary>
public static string SerializeObject(object o)
{
  char sep1 = '|';
  char sep2 = ',';
  char sep3 = '=';

  StringBuilder sb = new StringBuilder();

  FieldInfo[] fields = o.GetType().GetFields(BindingFlags.Instance | BindingFlags.Public |
    BindingFlags.NonPublic);

  foreach (FieldInfo field in fields)
  {
    object value = field.GetValue(o);

    if (value != null)
    {
      if (field.FieldType.GetInterface("IDictionary") != null)
      {
        foreach (object key in (value as IDictionary).Keys)
        {
          sb.AppendFormat("{0}{3}{1}{2}", key, (value as IDictionary)[key], sep2, sep3);
        }

        if (sb[sb.Length - 1] == sep2) sb.Remove(sb.Length - 1, 1);
      }
      else if (field.FieldType.GetInterface("IList") != null)
      {
        foreach (object v in (value as IList))
        {
          sb.AppendFormat("{0}{1}", v, sep2);
        }

        if (sb[sb.Length - 1] == sep2) sb.Remove(sb.Length - 1, 1);
      }
      else if (field.FieldType == typeof(Boolean))
      {
        sb.Append((bool)value ? "T" : "");
      }
      else
      {
        sb.Append(value);
      }
    }

    sb.Append(sep1);
  }

  if (sb[sb.Length - 1] == sep1) sb.Remove(sb.Length - 1, 1);
  return sb.ToString();
}

/// <summary>
/// 反序列化
/// </summary>
public static T DeserializeObject<T>(string s)
  where T : new()
{
  char sep1 = '|';
  char sep2 = ',';
  char sep3 = '=';

  T o = new T();

  FieldInfo[] fields = o.GetType().GetFields(BindingFlags.Instance | BindingFlags.Public |
    BindingFlags.NonPublic);

  string[] values = s.Split(sep1);

  for (int i = 0; i < fields.Length; i++)
  {
    FieldInfo field = fields[i];
    if (String.IsNullOrEmpty(values[i])) continue;

    if (field.FieldType.GetInterface("IDictionary") != null)
    {
      string[] vs = values[i].Split(sep2);

      IDictionary dictionary = field.GetValue(o) as IDictionary;

      Type key = field.FieldType.IsGenericType ?
        field.FieldType.GetGenericArguments()[0] : typeof(Object);
      Type value = field.FieldType.IsGenericType ?
        field.FieldType.GetGenericArguments()[1] : typeof(Object);

      if (dictionary == null)
      {
        dictionary = (IDictionary)Activator.CreateInstance(field.FieldType);
        field.SetValue(o, dictionary);
      }

      foreach (string v in vs)
      {
        string[] ns = v.Split(sep3);
        dictionary.Add(Convert.ChangeType(ns[0], key), Convert.ChangeType(ns[1], value));
      }
    }
    else if (field.FieldType.GetInterface("IList") != null)
    {
      string[] vs = values[i].Split(sep2);

      if (field.FieldType.IsArray)
      {
        Type t = field.FieldType.GetElementType();
        Array array = Array.CreateInstance(t, vs.Length);

        for (int x = 0; x < vs.Length; x++)
        {
          array.SetValue(Convert.ChangeType(vs[x], t), x);
        }

        field.SetValue(o, array);
      }
      else
      {
        IList list = field.GetValue(o) as IList;

        Type t = field.FieldType.IsGenericType ?
          field.FieldType.GetGenericArguments()[0] : typeof(Object);

        if (list == null)
        {
          list = (IList)Activator.CreateInstance(field.FieldType);
          field.SetValue(o, list);
        }

        foreach (string v in vs)
        {
          list.Add(Convert.ChangeType(v, t));
        }
      }
    }
    else if (field.FieldType == typeof(Boolean))
    {
      field.SetValue(o, values[i] == "T" ? true : false);
    }
    else if (field.FieldType.IsEnum)
    {
      field.SetValue(o, Enum.Parse(field.FieldType, values[i], true));
    }
    else
    {
      field.SetValue(o, Convert.ChangeType(values[i], field.FieldType));
    }
  }

  return o;
}

测试代码

[Serializable]
public class MyClass
{
  private int valueType;

  public int ValueType
  {
    get { return valueType; }
    set { valueType = value; }
  }

  private object obj;

  public object Object
  {
    get { return obj; }
    set { obj = value; }
  }

  private bool boolean;

  public bool Boolean
  {
    get { return boolean; }
    set { boolean = value; }
  }

  private string[] array;

  public string[] Array
  {
    get { return array; }
    set { array = value; }
  }

  private List<string> list;

  public List<string> List
  {
    get { return list; }
    set { list = value; }
  }

  private ArrayList arrayList;

  public ArrayList ArrayList
  {
    get { return arrayList; }
    set { arrayList = value; }
  }

  private Hashtable hashtable;

  public Hashtable Hashtable
  {
    get { return hashtable; }
    set { hashtable = value; }
  }

  private Dictionary<string, int> dictionary;

  public Dictionary<string, int> Dictionary
  {
    get { return dictionary; }
    set { dictionary = value; }
  }
}

class Program
{
  static void Main(string[] args)
  {
    //Test();

    MyClass o = new MyClass();
    o.List = new List<string>();
    o.Dictionary = new Dictionary<string, int>();
    o.ArrayList = new ArrayList();
    o.Hashtable = new Hashtable();

    o.ValueType = 123456;
    o.Object = DateTime.Now;
    o.Boolean = true;

    o.Dictionary.Add("dict1", 1);
    o.Dictionary.Add("dict2", 2);
    
    o.Array = new string[] { "array1", "array2", "array3" };
    
    o.List.Add("list1");
    o.List.Add("list2");
    
    o.ArrayList.Add("ArrayList1");
    o.ArrayList.Add("ArrayList2");
    
    o.Hashtable.Add("Hashtable1", 1);
    o.Hashtable.Add("Hashtable2", 2);

    // SerializeObject

    string s = SerializeObject(o);
    Console.WriteLine(s);

    MyClass m = DeserializeObject<MyClass>(s);
    Console.WriteLine(SerializeObject(m));

    // BinaryFormatter

    BinaryFormatter binary = new BinaryFormatter();
    MemoryStream stream = new MemoryStream();
    binary.Serialize(stream, o);
    s = Convert.ToBase64String(stream.ToArray());
    Console.WriteLine(s);
  }
}