Casting data in a data table returns string rather than type inserted

Question

I have a custom class that holds the value of a cell which is put into a data table using the following command:

table.Rows.Add(error[i].GetValues());

GetValues() returns an array of a generic class: DataParcel<KeyType, DataType, ParentType>. In this particular case, the class instance is DataParcel<string, string, Record>. When I turn around and try to get the data of a particular cell using this command:

DataParcel<string, string, Record> parcel = (StudentDataParcel)table.Rows[e.RowIndex].ItemArray[0];     

This causes an invalid cast exception... what am I missing? It says that the data is of the string class instead of the class I tried to put in the table.

Answer 1

Probably you did not specify the type of columns. Try something like this:

var table = new DataTable( );
table.Columns.Add( "Col1", typeof( DataParcel<string, string, Record> ) );
table.Columns.Add( "Col2", typeof( DataParcel<string, string, Record> ) );
table.Columns.Add( "Col3", typeof( DataParcel<string, string, Record> ) );
//...

DataParcel<string, string, Record> parcel = (DataParcel<string, string, Record>)table.Rows[e.Rowndex].ItemArray[0];

Specify enough number of columns. If you want to keep the array in a single, first column, then use table.Rows.Add((object)error[i].GetValues()) and make other obvious adjustments. (ItemArray[0] will represent an array).