Следуйте приведенному ниже фрагменту кода, который поможет вам подключиться к Crystal Report из кода C #.
CrystalReport1 myReport;
string connectionString = @"<Give your Connection String To Connect Access Database>(Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\4.accdb)";
string selectSQL = "<Provide the Query here to Retrieve Data>(Select ProductID,ProductName,ProductSpec From Products)";
OleDbConnection connection = new OleDbConnection(connectionString);
OleDbDataAdapter da = new OleDbDataAdapter(selectSQL, connection);
DataSet ds = new DataSet();
da.Fill(ds, "Test");
myReport = new CrystalReport1();
myReport.SetDataSource(ds);
myReportViewer1.ReportSource = myReport;
ds.Dispose();
connection.Close();