convert .net 4.0 syntax OfType to .net 3.5

Question

I have this .NET 4.0 code:

var myTable = tables[1];
myTable = tables.Item["Table1"];
myTable = tables.OfType<Excel.ListObject>().FirstOrDefault(t => t.Name == "Table1");

I am trying to compile with .NET 3.5 and getting a bunch of errors:

Error 23 Property, indexer, or event 'Item' is not supported by the language; try directly calling accessor method 'Microsoft.Office.Interop.Excel.ListObjects.get_Item(object)'

and

Error 24 'Microsoft.Office.Interop.Excel.ListObjects' does not contain a definition for 'OfType' and the best extension method overload 'System.Linq.Queryable.OfType(System.Linq.IQueryable)' has some invalid arguments

and

Error 25 Instance argument: cannot convert from 'Microsoft.Office.Interop.Excel.ListObjects' to 'System.Linq.IQueryable'

Can you please guide me on exactly what these errors mean so that I can try to convert this to .NET 3.5?

Thank you so much for your advice.

Answer 1

This question refers to an answer given for This command requires at least two rows of source data; the code is showing 3 different ways of accessing a table/listobject in code.

This was the code I posted:

    var myTable = tables[1];
    var myTable = tables.Item["Table1"];
    var myTable = tables.OfType<Excel.ListObject>().FirstOrDefault(t => t.Name == "Table1");

I meant to illustrate that there are different ways of accessing a table in code.

To put it in context, I have created a Ribbon with a single button called "TestButton". Here is the entire code, should work with 3.5:

using Excel = Microsoft.Office.Interop.Excel;


    private void TestButton_Click(object sender, RibbonControlEventArgs e)
    {
        var worksheet = (Excel.Worksheet) Globals.ThisAddIn.Application.ActiveSheet;
        var tables = worksheet.ListObjects;
        var table = tables.Item["Table1"]; // this is the line you are referring to

        //do something with table
    }