Code Sample for Hashtable Derivative for Type conversion

[Guest]

Hello,

I am using Hashtable class in my application to store key/value pairs. It
works great except the types returned are all objects. As a result, there are
type-casts everywhere making the code very hard to read. I believe it should
be relatively easy to derive a class from Hashtable that returns appropriate
types for my application. I started writing it like this

public class PeerTable : Hashtable {
public new PeerTable Clone() {
return (PeerTable)base.Clone();
}
}

But I don't know
1. How to make it return "MyValueType" type when I use something like
myPeerTable[key].
2. How to set dictionaryentry.Key to "MyKeyType" and dictionaryentry.Value
to "MyValueType".

I appreciate your help.

Regards,
Vinay Agarwal

 

[William Stacey [MVP]]

This was what generics are great at. 2.0 has generic Dictionary collection
for strong typing to your value. If you can only use 1.1, then I think the
only way to get that behavior is by wrapping the hashtable yourself and
implement the required methods and enumerator(s).

 

[Nicholas Paldino [.NET/C# MVP]]

In .NET 1.1 and before, you would derive from the DictionaryBase class.
It provides most of the functionality you need, you just need to provide the
type-safe methods.

Hope this helps.


--
- Nicholas Paldino [.NET/C# MVP]
- (e-mail address removed)

This was what generics are great at. 2.0 has generic Dictionary
collection for strong typing to your value. If you can only use 1.1, then
I think the only way to get that behavior is by wrapping the hashtable
yourself and implement the required methods and enumerator(s).

--
William Stacey [MVP]

Hello,

I am using Hashtable class in my application to store key/value pairs. It
works great except the types returned are all objects. As a result, there
are
type-casts everywhere making the code very hard to read. I believe it
should
be relatively easy to derive a class from Hashtable that returns
appropriate
types for my application. I started writing it like this

public class PeerTable : Hashtable {
public new PeerTable Clone() {
return (PeerTable)base.Clone();
}
}

But I don't know
1. How to make it return "MyValueType" type when I use something like
myPeerTable[key].
2. How to set dictionaryentry.Key to "MyKeyType" and
dictionaryentry.Value
to "MyValueType".

I appreciate your help.

Regards,
Vinay Agarwal

 

[Guest]

Wow! I didn't know of this feature in 2.0. Since I am using 2.0, I will
simply switch to Dictionary instead of Hashtable.

I should hang out here more often to get ideas like this. Thanks a lot.

Regards,
Vinay