Question

All, I am having difficulty passing a struct to a class constructor. I am in the process of multi-threading a part of an existing code. In one class the following structure is defined:

SchemaFileRec[] m_TableList;

struct SchemaFileRec
{
    public ArrayList  saFile;
    public ArrayList  saImpTab;
    public ArrayList  saSheet;
    // And others...
    public int[]      nColHead;
    public int[]      nSkipBeg;
    public int[]      nSkipEnd;
    public string     strADTFld;
};

This is used in a method (old method called ExecCmd) to do some processing. I am re-writing this method to a class; in fact a subclass of BackgroundWorker. Essentally I am taking a method that deals with some “long-running” task, and multi-thredding it. I have:

public class ExecCmdsThredded : BackgroundWorker 
{
    // Global variables and constants.
    private int nTable;
    private List<int> kPrmArray = null;
    private List<object> StructureArray = null;
    private SpreadsheetGear.IWorksheet worksheet;

    // Default constructor to handle thred properties.
    public ExecCmdsThredded()
    {
        WorkerReportsProgress = true;
        WorkerSupportsCancellation = true;
    }

    // Constructor to parse relevant parameters to worker.
    // Or as an array of objects public ExecCmdsThredded(object[] _StructArr, etc. 
    public ExecCmdsThredded(List<object> _StructArr, List<int> _kPrmArr, ArrayList[] _saCmd, 
                            int _nTable, SpreadsheetGear.IWorksheet _worksheet) : this()
    {
        this.nTable = _nTable;
        this.kPrmArray = _kPrmArr;
        this.StructureArray = _StructArr;
        this.worksheet = _worksheet;
    } 
    // ...

I now want to pass the structure from above to ExecCmdsThredded class via the constructor but I have never had to do this before and I am not sure if it is possible the way I want to do it? I could explicitly pass every componant of the struct but I want to avoid this.

Thanks for your time.

Answer 1

I feel uncomfortable whenever I start passing structs. When you have a collection of structs that you want to pass as a parameter, carefully revisit the design …”why am I using a struct?” I recommend converting the struct to a class in most cases.

There are several links to help you decide on whether to use a struct or class. Search through StackOverflow and MSDN