Is ist possible to share viewstate properties between webparts?

Question

I have a class "Wepart A" and a class "Webpart B" which have some similiarities. So I introduced a BaseWebpart from which A and B inherit.

I want to share 2 properties (SortColumn and SortDirection) which are stored in viewstate:

protected string SortRow
{
  get
  {
    object o = ViewState["SortRow"];
    if (o == null)
    {
      return String.Empty;
    }
    return (string)o;
  }
  set
  {
    if (value == SortRow)
    {
      SortAscending = !SortAscending;
    }
    ViewState["SortRow"] = value;
  }
}

protected bool SortAscending
{
  get
  {
    object o = ViewState["SortAscending"];
    if (o == null)
    {
      return true;
    }
    return (bool)o;
  }
  set
  {
    ViewState["SortAscending"] = value;
  }
}

and put them to the BaseWebpart. Can I access them in Webpart A and B without problems? I guess the ViewState-Keys could be a problem...any suggestions?

Answer 1

I think you answered your own question in your comment:

So I better go for using getter and setter methods with different keys for the viewstate.

You can have a unique key with 'this.ID', which give you the webpart 'guid'. If you want to share similar logic between webparts or controls in general, you can also create a static 'helper' class.

Answer 2

Its better to use web part connections for this purpose. You can make one web part as Connection Provider and other as Connection Consumer and define a static connection between them.

Answer shared from this post -

http://social.msdn.microsoft.com/Forums/en/sharepointdevelopment/thread/d9bdafab-5cb1-4b2e-ae04-a63446f8404e

Answer 3

Because the ViewState property is marked as protected, you can't get a control's(or webpart) ViewState in another.

If you want to share data between page controls\webparts per-request basis(similar to viewstate), use HttpContext.Items instead.