从Excel文件读取

Question

I have seen many examples of this around but something isn't working for me.

What I am looking to do is to read an Excel sheet, given a sheet and store those values into Lists.

For example, say I have an excel file that looks like:

First   Second  Third
f1      s1      t1
f2      s2      t2
f3      s3      t3

Each row is to be considered a set of values.

This is what I have doing so far:

List<string> ColumnNames= GetColumnNames();

        using (OleDbConnection OleDbConn = new OleDbConnection(Path))
        {
            OleDbConn.Open();
            String cmdString = "SELECT * FROM [" + sheetName+ "]";
            OleDbCommand cmd = new OleDbCommand(cmdString, OleDbConn);
            DataTable dt = new DataTable();
            List<ValueSet> sets = new List<ValueSet>();
            Dictionary<string, Value> values = new Dictionary <string,value>()
            ValueSet valueset = new ValueSet(null);
            using (OleDbDataReader oleRdr = cmd.ExecuteReader())
            {
                while (oleRdr.Read())
                {
                    for (int i = 0; i < ColumnNames.Count; i++)
                    {
                        ColumnName cn = new ColumnName(columnNames[i]);

                        string data= oleRdr[f.Name].ToString();
                        Value value = new Value(data, f);

                        if (!values.ContainsKey(ColumnNames[i]))
                        {
                            values.Add(ColumnNames[i], value);
                        }
                        else
                        {
                            values[ColumnNames[i]] = value;
                        }
                    }
                    valueSet= new ValueSet(values);
                    sets.Add(valueSet);
                }
                return sets;;
            }

Answer 1

I've gotten weird results with certain files using an OleDbConnection .

I suggest http://www.codeproject.com/Articles/11698/A-Portable-and-Efficient-Generic-Parser-for-Flat-F

With this you can read your CSV into a datatable and parse it into a list as follows:

DataTable dtPrereg;

using (GenericParserAdapter gp = new GenericParserAdapter(Server.MapPath("prereg.csv"), Encoding.UTF8))
{
    gp.FirstRowHasHeader = true;
    dtPrereg = gp.GetDataTable();
}

I haven't tested this on tab delimited files, but it should work the same (or you could convert your file to CSV)

Answer 2

If you really have a spreadsheet with a known number of named columns and you want to project them into a List<List<string>> it's a lot easier to just do it with Linq.

eg

List<List<string>> data;

using (OleDbDataReader rdr = cmd.ExecuteReader())
{
    data = (from row in rdr.Cast<DbDataRecord>()
            select new List<string>
            {
                row["First"].ToString(),
                row["Second"].ToString(),
                row["Third"].ToString()
            }).ToList();

}

Answer 3

try changing

 ValueSet= new ValueSet(values);
 sets.Add(ValueSet);

to

valueset = new ValueSet(values);
sets.Add(valueset );