Serialization and hashtable

[Cederstrom]

Hello group!

I want to create a config/status object, that will contain a Hashtable. This
object I would like to save through Serialization, but im having some
trouble. My hashtable contain some objects, from a class I created myself.

I read that I need to make my own "add" method, which I hopefully did
correct. I hope someone can spot my wrongdoings, and point me in the right
direction. The code is in the bottom of this post:

Thanks

---ooo---

using System;
using System.IO;
using System.Collections;
using System.Runtime.Serialization.Formatters.Binary;
using System.Runtime.Serialization;

namespace MyTest
{
/// <summary>
/// Have all configuration options in it
/// </summary>
[Serializable]
public class Config
{
public Groups groups = new Groups();

public Config()
{
Serialize();
Deserialize();
}

private void Serialize()
{
// Create a hashtable of values that will eventually be serialized.
groups.Add(new Groups.Group("test1"));
groups.Add(new Groups.Group("test2"));
groups.Add(new Groups.Group("test3"));

// To serialize the hashtable and its key/value pairs,
// you must first open a stream for writing.
// In this case, use a file stream.
FileStream fs = new FileStream(@"C:\DataFile.dat", FileMode.Create);

// Construct a BinaryFormatter and use it to serialize the data to the
stream.
BinaryFormatter formatter = new BinaryFormatter();
try
{
formatter.Serialize(fs, groups);
}
catch (SerializationException e)
{
Console.WriteLine("Failed to serialize. Reason: " + e.Message);
throw;
}
finally
{
fs.Close();
}
}


private void Deserialize()
{
// Declare the groups reference.
groups = null;

// Open the file containing the data that you want to deserialize.
FileStream fs = new FileStream(@"C:\DataFile.dat", FileMode.Open);
try
{
BinaryFormatter formatter = new BinaryFormatter();
// Deserialize the hashtable from the file and
// assign the reference to the local variable.
groups = (Groups) formatter.Deserialize(fs);
}
catch (SerializationException e)
{
Console.WriteLine("Failed to deserialize. Reason: " + e.Message);
throw;
}
finally
{
fs.Close();
}

// To prove that the table deserialized correctly,
// display the key/value pairs.
foreach (DictionaryEntry de in groups)
{
Console.WriteLine("{0} lives at {1}.", de.Key, de.Value);
}
}

public class Groups : Hashtable
{
public virtual void Add(Group group)
{
//forward our Add method on to the standard hashtable add method
base.Add(group.getKey(),group);
}

//this is the indexer (readonly)
public virtual new Group this[object key]
{
get
{
//return the Group at IList[Index]
return (Group)base[key];
}
}
public class Group
{
string key;

public Group(string arg)
{
key = arg;
}
public string getKey()
{
return key;
}
}
}
}
}

 

[Zürcher See]

If you want to create a config/status object, why you don't use an
XmlDocument?

Hello group!

I want to create a config/status object, that will contain a Hashtable. This
object I would like to save through Serialization, but im having some
trouble. My hashtable contain some objects, from a class I created myself.

I read that I need to make my own "add" method, which I hopefully did
correct. I hope someone can spot my wrongdoings, and point me in the right
direction. The code is in the bottom of this post:

Thanks

---ooo---

using System;
using System.IO;
using System.Collections;
using System.Runtime.Serialization.Formatters.Binary;
using System.Runtime.Serialization;

namespace MyTest
{
/// <summary>
/// Have all configuration options in it
/// </summary>
[Serializable]
public class Config
{
public Groups groups = new Groups();

public Config()
{
Serialize();
Deserialize();
}

private void Serialize()
{
// Create a hashtable of values that will eventually be serialized.
groups.Add(new Groups.Group("test1"));
groups.Add(new Groups.Group("test2"));
groups.Add(new Groups.Group("test3"));

// To serialize the hashtable and its key/value pairs,
// you must first open a stream for writing.
// In this case, use a file stream.
FileStream fs = new FileStream(@"C:\DataFile.dat", FileMode.Create);

// Construct a BinaryFormatter and use it to serialize the data to the
stream.
BinaryFormatter formatter = new BinaryFormatter();
try
{
formatter.Serialize(fs, groups);
}
catch (SerializationException e)
{
Console.WriteLine("Failed to serialize. Reason: " + e.Message);
throw;
}
finally
{
fs.Close();
}
}


private void Deserialize()
{
// Declare the groups reference.
groups = null;

// Open the file containing the data that you want to deserialize.
FileStream fs = new FileStream(@"C:\DataFile.dat", FileMode.Open);
try
{
BinaryFormatter formatter = new BinaryFormatter();
// Deserialize the hashtable from the file and
// assign the reference to the local variable.
groups = (Groups) formatter.Deserialize(fs);
}
catch (SerializationException e)
{
Console.WriteLine("Failed to deserialize. Reason: " + e.Message);
throw;
}
finally
{
fs.Close();
}

// To prove that the table deserialized correctly,
// display the key/value pairs.
foreach (DictionaryEntry de in groups)
{
Console.WriteLine("{0} lives at {1}.", de.Key, de.Value);
}
}

public class Groups : Hashtable
{
public virtual void Add(Group group)
{
//forward our Add method on to the standard hashtable add method
base.Add(group.getKey(),group);
}

//this is the indexer (readonly)
public virtual new Group this[object key]
{
get
{
//return the Group at IList[Index]
return (Group)base[key];
}
}
public class Group
{
string key;

public Group(string arg)
{
key = arg;
}
public string getKey()
{
return key;
}
}
}
}
}

 

[Cederstrom]

If you want to create a config/status object, why you don't use an

XmlDocument?

Because it would be alot easier to just serialize a hashtable/object, and
deserialize it when I need to load the data.

Unless im missing something about XmlDocument's ?

 

[Zürcher See]

Config files usually have only string and number, not objects.

We use XmlDocuments as config file to run some applications, it has many
advantages:
-you can edit it with a text editor
-you can add and remove data without problem
-you can build also very complex struct
-very easy to parse, also with complex struct
-XmlDocument has Save and Load methods so that everything become simpler

If I had to save an object with the configuration,
I would save the object in a directory and add the path to the config file

I'm not sure but I think you can also serialize an object to xml,
in that case you can also add it to the xml config file