> Beside what the rest said, I would advise you to prefer a generic collection
> always, as the non-generic once can be slowly phased out as versions pass.
> Indeed, the .NET framework for Silverlight doesn't have them available
> anymore. Generics are also better type-safe and performance wise, and lead
> to much cleaner code in general in my opinion.
For performance, there's one exception: binary serialization of a
Dictionary<T, U>. This is tremendously slow compared to a Hashtable. For
serialization purposes use something like this:
/// <summary>
/// Utility class which can be used instead of a normal Dictionary class when
the Dictionary class is serialized. This class is faster and
/// has much less overhead than the normal dictionary class, as it doesn't use
generic types. Has no additional value for CF.NET
/// </summary>
/// <typeparam name="TKey">Key type</typeparam>
/// <typeparam name="TValue">Value type</typeparam>
[Serializable]
public class FastDictionary<TKey, TValue> : Dictionary<TKey, TValue>
{
#region Class Member Declarations
[NonSerialized]
private SerializationInfo _info;
#endregion
/// <summary>
/// CTor
/// </summary>
/// <param name="capacity"></param>
public FastDictionary( int capacity )
: base( capacity )
{
}
/// <summary>
/// CTor
/// </summary>
public FastDictionary() : base()
{
}
/// <summary>
/// CTor
/// </summary>
/// <param name="d"></param>
public FastDictionary(IDictionary<TKey, TValue> d)
: base( d )
{
}
/// <summary>
/// Deserialization CTor
/// </summary>
/// <param name="info"></param>
/// <param name="context"></param>
protected FastDictionary(SerializationInfo info, StreamingContext
context)
{
_info = info;
}
/// <summary>
/// Implements the <see
cref="T:System.Runtime.Serialization.ISerializable"></see> interface and
returns the data needed to serialize the <see
cref="T:System.Collections.Generic.Dictionary`2"></see> instance.
/// </summary>
/// <param name="info">A <see
cref="T:System.Runtime.Serialization.SerializationInfo"></see> object that
contains the information required to serialize the <see
cref="T:System.Collections.Generic.Dictionary`2"></see> instance.</param>
/// <param name="context">A <see
cref="T:System.Runtime.Serialization.StreamingContext"></see> structure that
contains the source and destination of the serialized stream associated with
the <see cref="T:System.Collections.Generic.Dictionary`2"></see>
instance.</param>
/// <exception cref="T:System.ArgumentNullException">info is
null.</exception>
public override void
GetObjectData(System.Runtime.Serialization.SerializationInfo info,
System.Runtime.Serialization.StreamingContext context)
{
object[] keys = new object[base.Count];
object[] values = new object[base.Count];
int i = 0;
foreach(KeyValuePair<TKey, TValue> pair in this)
{
keys[i] = pair.Key;
values[i] = pair.Value;
i++;
}
info.AddValue("keys", keys);
info.AddValue("values", values);
}
/// <summary>
/// Implements the <see
cref="T:System.Runtime.Serialization.ISerializable"></see> interface and
raises the deserialization event when the deserialization is complete.
/// </summary>
/// <param name="sender">The source of the deserialization
event.</param>
/// <exception
cref="T:System.Runtime.Serialization.SerializationException">The <see
cref="T:System.Runtime.Serialization.SerializationInfo"></see> object
associated with the current <see
cref="T:System.Collections.Generic.Dictionary`2"></see> instance is
invalid.</exception>
public override void OnDeserialization(object sender)
{
object[] keys = (object[])_info.GetValue("keys",
typeof(object[]));
object[] values = (object[])_info.GetValue("values",
typeof(object[]));
for(int i = 0; i < keys.Length; i++)
{
base.Add((TKey)keys[i], (TValue)values[i]);
}
}
}
FB
>
> Regards,
> --
> Martín Salías
> www.Salias.com.ar
> Agile Alliance Member - Microsoft MVP
>
>
> On 7/3/07, Russell Collins <[EMAIL PROTECTED]> wrote:
> >
> > I am trying to determine if I should use a generic List<T> or a
> > HashTable to hold some data objects. The main thing is that I want to
> > know if there is general knowledge that one just performs better than
> > the other. Any feedback would be greatly appreciated.
> >
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