Spread Windows Forms 13.0 Product Documentation
Spread Windows Forms 13.0 Product Documentation / Developer's Guide / Managing Data Binding / Binding to Data / Binding a Combo Box to a DataReader
In This Topic
    Binding a Combo Box to a DataReader
    In This Topic

    You can bind a combo box to a DataReader. A DataReader lets you access data in a read-only, forward-only way from a data source. Using a DataReader is often a quick way of returning results, as illustrated in the following example for populating results in a combo box.

    Example

    This example adds data to a combo cell from a data source.

    C#
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    /// Set up a connection to the database. The database name is an example.
    string dbpath = "c:\\reader.mdb";
    System.Data.OleDb.OleDbConnection dbConn = new System.Data.OleDb.OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;DATA SOURCE=" + dbpath);
    /// Open a connection and a SELECT command.
    dbConn.Open();
    System.Data.OleDb.OleDbCommand dbCommand = new System.Data.OleDb.OleDbCommand("SELECT * FROM Table1", dbConn);
    /// Open a DataReader on that connection and command.
    System.Data.OleDb.OleDbDataReader dr = dbCommand.ExecuteReader(System.Data.CommandBehavior.CloseConnection);
    /// Loop through the rows returned by the reader.
    ArrayList al = new ArrayList();
    while (dr.Read()) {
         al.Add(dr("Data"));
    }
    /// Populate combo box with data converted to strings.
    string[] s;
    s = al.ToArray(typeof(string));
    FarPoint.Win.Spread.ComboBoxCellType cb = new FarPoint.Win.Spread.ComboBoxCellType();
    cb.Items = s;
    fpSpread1.ActiveSheetView.Cells(0, 0).CellType = cb;
    /// Dispose connection.
    dbConn.Dispose();
    VB
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    ' Set up a connection to the database. The database name is an example.
    Dim dbpath As String = "c:\reader.mdb"
    Dim dbConn As New System.Data.OleDb.OleDbConnection( _
    "Provider=Microsoft.Jet.OLEDB.4.0;DATA SOURCE=" & dbpath)
    ' Open a connection and a SELECT command.
    dbConn.Open()
    Dim dbCommand As New System.Data.OleDb.OleDbCommand( _
    "SELECT * FROM Table1", dbConn)
    ' Open a DataReader on that connection and command.
    Dim dr As System.Data.OleDb.OleDbDataReader = dbCommand.ExecuteReader(System.Data.CommandBehavior.CloseConnection)
    ' Loop through the rows returned by the reader.
    Dim al As New ArrayList()
    While dr.Read()
         al.Add(dr("Data"))
    End While
    ' Populate combo box with data converted to strings.
    Dim s As String()
    s = al.ToArray(GetType(String))
    Dim cb As New FarPoint.Win.Spread.ComboBoxCellType
    cb.Items = s
    fpSpread1.ActiveSheetView.Cells(0, 0).CellType = cb
    ' Dispose connection.
    dbConn.Dispose()