Creating public properties in sandboxed webpart solutions

Question

I'm trying to port a farm solution to a sandboxed one, and I can't figure out how to port this piece of code:

[ToolboxItem(false)]
public partial class vClockPartSB : System.Web.UI.WebControls.WebParts.WebPart
{
    [Personalizable(PersonalizationScope.User)]
    public Collection<String> ClockTimeZones { get; set; }
    [Personalizable(PersonalizationScope.User)]
    public int NumberOfClocks { get; set; }
    [Personalizable(PersonalizationScope.User)]
    public string DdlMain { get; set; }
    [Personalizable(PersonalizationScope.User)]
    public string DdlSubOne { get; set; }
    [Personalizable(PersonalizationScope.User)]
    public string DdlSubTwo { get; set; }
    [Personalizable(PersonalizationScope.User)]
    public string DdlSubThree { get; set; }
    [Personalizable(PersonalizationScope.User)]
    public string DdlSubFour { get; set; }



    protected override void OnInit(EventArgs e)
    {
        ClockTimeZones = new Collection<string>();
        base.OnInit(e);
        InitializeControl();
    }

I get the following error:

Web Part Error: Unhandled exception was thrown by the sandboxed code wrapper's Execute method in the partial trust app domain: Web part property 'ClockTimeZones' uses unsupported type (System.Collections.ObjectModel.Collection`1[[System.String, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]]), and cannot be run as a sandboxed code web part.

How should I approach it?

Answer 1

I would be tempted just to store a string - rather than a collection of strings - and perform my own serialisation/deserialisation. Probably using the string.Split() function and a suitable delimiter.

Answer 2

The System.Collections.ObjectModel namespace is not allowed in the Sandbox.

For your scenario, could you use the List< string > instead?

Answer 3

Apparently, only the following types are supported as the properties of the web part in the sandbox solution:

• string
• bool
• Enum
• short
• int
• Guid
• Uri
• byte
• char
• long
• float
• decimal
• double

Here is a link to Alan Dahl's blog article where Alan Dahls' blog did the search.