Question

I have a.NET class that I want to use from both C# and PowerShell. Cut down to its bare bones, it’s something like this:

class Record
{
    Dictionary<string, string> _fields = new Dictionary<string, string>();
    public IDictionary<string, string> Fields { get { return _fields; } }
    //...other stuff...
}

So I get a Record from somewhere and I can do record.Fields[“foo”] = “bar” to modify/add fields from either C# or PowerShell. Works great.

But I’d like to make it a little more PowerShell-friendly. I want to do record.foo = “bar” and have it call the appropriate getters and setters. (I’d like to do the same with C# at some point, probably using dynamic, but that’s a separate fun project). Seems like I need a wrapping proxy class.

I know about add-member but I am worried that it would be slow and use a lot of memory when dealing with tens of thousands of records. I also don’t know how to have it handle record.somenewvalue = “abc”.

I’m guessing that I want to create my proxy class in C#, using the facilities in System.Management.Automation or Microsoft.PowerShell but don’t quite know where to start. Can anyone help point me in the right direction?

Answer 1

I figured out one way to do it. Just make Record itself a dictionary. Here’s some sample code:

$source = @"
    using System.Collections.Generic;
    public class Record : Dictionary<string, object>
    {
    }
"@

add-type -typedefinition $source

$x = new-object record
$x.add('abc', '1') # add
$x['def'] = '2'    # indexer
$x.ghi = 3         # "member"

$x

It outputs:

Key     Value                                                       
---     -----                                                       
abc     1                                                           
def     2                                                           
ghi     3