MemberShip中对用户资料的序列化

MemberShip中对用户资料的序列化

前面在《Asp.Net Forums中对.Net中序列化和反序列化的应用》一文中讲了，对于一些扩展属性，可以将字符串集合序列化为二进制，也可以从二进制反序列化为字符串集合。其实我一直有个疑问，对于asp.net中可以很容易实现，但是在asp中该如何？

在CS和DNN3中都采用了asp.net2.0的新特性MemberShip，今天研究了一下CSBeta2，特地研究了一下MemberShip中对于用户资料的序列化保存。发现在aspnet_Profile表中有三个特殊字段PropertyNames、PropertyValuesString和PropertyValuesBinary，其中的PropertyValuesBinary十之八九就是保存序列化为二进制后的内容。对于PropertyNames、PropertyValuesString这两个字段倒是不知道，打开查看，发现其中一条记录这两个字段的内容分别为下面两行的内容：

publicEmail:S:0:0:yahooIM:S:0:0:timezone:S:0:1:birthdate:B:0:-1:gender:S:1:6:location:S:7:0:fontsize:S:7:1:signature:S:8:0:dateFormat:S:8:10:webLog:S:18:7:enablePostPreviewPopup:B:0:-1:language:S:25:5:interests:S:30:0:occupation:S:30:0:webAddress:S:30:7:icqIM:S:37:0:aolIM:S:37:0:signatureFormatted:S:37:0:msnIM:S:37:0:

8NotSet0MM-dd-yyyyhttp://zh-CNhttp://

借助Reflector分析了一下源码，终于明白了，原来在PropertyNames字段中，由“:”分割为若干个数组，其中每个属性占数组的4项（如publicEmail:S:0:0:为一个属性的整体）：
第1项为属性名称
第2项有两种可能值，B表示该属性值为null，S表示不为null
第3项表示在PropertyValuesString字段中字符串的起始位置
第4项表示长度
那么publicEmail:S:0:0:就表示为空值，timezone:S:0:1:表示“8NotSet0MM-dd-yyyyhttp://zh-CNhttp://“中从0开始取1个字符长度为“8”，birthdate:B:0:-1:就表示为null，dateFormat:S:8:10:就表示取“8NotSet0MM-dd-yyyyhttp://zh-CNhttp://”中第8位开始取10个字符为“MM-dd-yyyy”……

通过这种序列化为字符串的方式，即使是一些弱语言，如vbscript,jscript都可以实现序列化和反序列化了，那么在asp中也就可以共享asp.net的MemberShip了。

贴两段核心代码参考一下：

internal static void PrepareDataForSaving(ref string allNames, ref string allValues, ref byte[] buf, bool binarySupported, SettingsPropertyValueCollection properties, bool userIsAuthenticated)
{
      StringBuilder builder1 = new StringBuilder();
      StringBuilder builder2 = new StringBuilder();
      MemoryStream stream1 = binarySupported ? new MemoryStream() : null;
      try
      {
            bool flag1 = false;
            foreach (SettingsPropertyValue value1 in properties)
            {
                  if (!value1.IsDirty)
                  {
                        continue;
                  }
                  if (userIsAuthenticated || ((bool) value1.Property.Attributes["AllowAnonymous"]))
                  {
                        flag1 = true;
                        break;
                  }
            }
            if (!flag1)
            {
                  return;
            }
            foreach (SettingsPropertyValue value2 in properties)
            {
                  if (!userIsAuthenticated && !((bool) value2.Property.Attributes["AllowAnonymous"]))
                  {
                        continue;
                  }
                  if (value2.IsDirty || !value2.UsingDefaultValue)
                  {
                        int num1 = 0;
                        int num2 = 0;
                        string text1 = null;
                        if (value2.Deserialized && (value2.PropertyValue == null))
                        {
                              num1 = -1;
                        }
                        else
                        {
                              object obj1 = value2.SerializedValue;
                              if (obj1 == null)
                              {
                                    num1 = -1;
                              }
                              else
                              {
                                    if (!(obj1 is string) && !binarySupported)
                                    {
                                          obj1 = Convert.ToBase64String((byte[]) obj1);
                                    }
                                    if (obj1 is string)
                                    {
                                          text1 = (string) obj1;
                                          num1 = text1.Length;
                                          num2 = builder2.Length;
                                    }
                                    else
                                    {
                                          byte[] buffer1 = (byte[]) obj1;
                                          num2 = (int) stream1.Position;
                                          stream1.Write(buffer1, 0, buffer1.Length);
                                          stream1.Position = num2 + buffer1.Length;
                                          num1 = buffer1.Length;
                                    }
                              }
                        }
                        string[] textArray1 = new string[8] { value2.Name, ":", (text1 != null) ? "S" : "B", ":", num2.ToString(CultureInfo.InvariantCulture), ":", num1.ToString(CultureInfo.InvariantCulture), ":" } ;
                        builder1.Append(string.Concat(textArray1));
                        if (text1 != null)
                        {
                              builder2.Append(text1);
                        }
                  }
            }
            if (binarySupported)
            {
                  buf = stream1.ToArray();
            }
      }
      catch
      {
            throw;
      }
      finally
      {
            if (stream1 != null)
            {
                  stream1.Close();
            }
      }
      allNames = builder1.ToString();
      allValues = builder2.ToString();
}
internal static void ParseDataFromDB(string[] names, string values, byte[] buf, SettingsPropertyValueCollection properties)
{
      for (int num1 = 0; num1 < (names.Length / 4); num1++)
      {
            string text1 = names[num1 * 4];
            SettingsPropertyValue value1 = properties[text1];
            if (value1 != null)
            {
                  int num2 = int.Parse(names[(num1 * 4) + 2], CultureInfo.InvariantCulture);
                  int num3 = int.Parse(names[(num1 * 4) + 3], CultureInfo.InvariantCulture);
                  if (num3 == -1)
                  {
                        if (!value1.Property.PropertyType.IsValueType)
                        {
                              value1.PropertyValue = null;
                              value1.IsDirty = false;
                              value1.Deserialized = true;
                        }
                  }
                  else
                  {
                        if (((names[(num1 * 4) + 1] == "S") && (num2 >= 0)) && ((num3 > 0) && (values.Length >= (num2 + num3))))
                        {
                              value1.SerializedValue = values.Substring(num2, num3);
                        }
                        if (((names[(num1 * 4) + 1] == "B") && (num2 >= 0)) && ((num3 > 0) && (buf.Length >= (num2 + num3))))
                        {
                              byte[] buffer1 = new byte[num3];
                              Buffer.BlockCopy(buf, num2, buffer1, 0, num3);
                              value1.SerializedValue = buffer1;
                        }
                  }
            }
      }
}