Programmatic definition of typeof from correlation DataTable

Question

Friends, I'm building a simple foreach loop that gets information from a DataTable (tblCORR) and creates 3 other DTs with it (tblCEMVALVE, tblLOG, tblNUMBER). The caveat is that it must use different column types according to what is provided in tblCORR, but of course typeof won't allow row.ItemArray[2] as the type.

tblCORR looks like this:

LAS.V342.B.REM.ST   V342_REM    bool    tblLOG      tblVALVE
CEM.CV44.B.REM.ST   CV44_REM    bool    tblCEMVALVE tblVALVE
CEM.FRT01.PTO06.ST  FR_PTO06    bool    tblLOG      tblSTATUS
CEM.GB02.GEAR.CTR   RR_GEAR_SEL byte    tblLOG      tblSTATUS
CEM.PT21.I_PRES.PSI PT21_PRESS  Short   tblNUMBER   tblDATA
RCP.ADD1.NAME.TXT   LAS_ADD1    string  tblNUMBER   tblLAS

Is there a way to do it without having to put a bunch of IFs in each case?

Thanks in advance!

foreach (DataRow row in tblCORR.Rows)
{
    switch (row.ItemArray[3].ToString())
    {
        case "tblCEMVALVE":
        {
            tblCEMVALVE.Columns.Add(row.ItemArray[1].ToString(), typeof(row.ItemArray[2]));
            break;
        }
        case "tblLOG":
        {
            tblLOG.Columns.Add(row.ItemArray[1].ToString(), typeof(row.ItemArray[2]));
            break;
        }
        case "tblNUMBER":
        {
            tblNUMBER.Columns.Add(row.ItemArray[1].ToString(), typeof(row.ItemArray[2]));
            break;
        }
    }
}

Answer 1

With that type names (they're not name of classes/structs in System namespace) one possible solution is to use a Dictionary. For example (verbose code for illustration purposes):

Dictionary<object, Type> knownTypes = new Dictionary<object, Type>();
knownTypes.Add("bool", typeof(bool));
knownTypes.Add("byte", typeof(byte));
knownTypes.Add("Short", typeof(short));
knownTypes.Add("string", typeof(string));

To be used as:

tblLOG.Columns.Add(row.ItemArray[1].ToString(), knownTypes[row.ItemArray[2]]);

Some changes you may/should consider:

• Make dictionary a static and private class member.
• Use a typed key for dictionary (using row.ItemArray[2].ToString()).
• Use a case insensitive comparer StringComparer.InvariantCultureIgnoreCase for dictionary key (if string) so short and Short will be equivalent.
• Use a similar technique for tables too (tblLOG, tblNUMBER and tblCEMVALVE) or directly search them using their TableName inside DataSet.