How to get an array in Excel from a C# xll?

Question

In my C# xll, I have a string array. I can read it from VB in Excel one element at a time, with the following code on c# side:

public int NumColumns()
{
    return _columns.Count;
}

public string ColumnName(int columnNumber)
{
    return _columns[columnNumber];
}

and this code in VB on Excel side:

 n = Application.Run("NumColumns")
 s = Application.Run("ColumnName", 1)

Can I transfer the whole array at once?