northwinddata.cs

用VS。NET基于wince

using System;
using System.Text;
using System.Windows.Forms;
using System.Data;
using System.Data.SqlServerCe;

namespace Microsoft.Sql.SqlCe.Samples.Cs.NorthwindCe {

    /// <summary>
    /// Summary description for NorthwindData.
    /// </summary>
    internal class NorthwindData {
        static NorthwindData     northwind = null;

        private readonly string  localDatabaseFile;
        private readonly string  localConnString;

        private SqlCeConnection  cnNorthwind;
        private DataSet          dsNorthwind;


        private NorthwindData() {
            localDatabaseFile = @"My Documents\NorthwindDemo.sdf";

            // Construct the local connecting string.
            //
            localConnString = @"Data Source= " + localDatabaseFile;

            cnNorthwind = new SqlCeConnection(localConnString);
            dsNorthwind = new DataSet("Northwind");
        }

        ~NorthwindData() {
        }

        public SqlCeConnection NorthwindConnection {
            get {
                return cnNorthwind;
            }
        }

        public DataSet NorthwindDataSet {
            get {
                return dsNorthwind;
            }
        }

        public string LocalDatabaseFile {
            get {
                return localDatabaseFile;
            }
        }

        public string LocalConnString {
            get {
                return localConnString;
            }
        }

        public static NorthwindData GetInstance() {
            if (null == northwind)
                northwind = new NorthwindData();

            return northwind;
        }

        public void Close() {
            if (ConnectionState.Open == cnNorthwind.State) {
                cnNorthwind.Close();
            }
        }

        internal static void ShowErrors(SqlCeException e) {
            // Show SQL Server CE error information. 
            //
            SqlCeErrorCollection errorCollection = e.Errors;

            StringBuilder bld = new StringBuilder();
            Exception   inner = e.InnerException;

            if (null != inner) {
                MessageBox.Show("Inner Exception: " + inner.ToString(), "Northwind");
            }

            foreach (SqlCeError err in errorCollection) {
                bld.Append("\n Error Code: " + err.HResult.ToString("X"));
                bld.Append("\n Message   : " + err.Message);
                bld.Append("\n Minor Err.: " + err.NativeError);
                bld.Append("\n Source    : " + err.Source);
                
                foreach (int numPar in err.NumericErrorParameters) {
                    if (0 != numPar) bld.Append("\n Num. Par. : " + numPar);
                }
                
                foreach (string errPar in err.ErrorParameters) {
                    if (String.Empty != errPar) bld.Append("\n Err. Par. : " + errPar);
                }

                MessageBox.Show(bld.ToString(), "Northwind");
                bld.Remove(0, bld.Length);
            }
        }
    }
}