前面讨论了数据库部分地设计和实现，现在开始真正的用C#编码了。
这里我都是将设计和实现结合在一起写的，从层次结构上来说应该更加清晰吧。
4、 核心代码设计
核心代码主要是封装一些公用的功能，以后的数据层，商务层代码会继承核心代码，并且统一利用核心代码所提供的功能。核心代码类是抽象类，不可以实例化得。
Coofucoo.Core.DbObject：此类是所有数据层类得基类
using System;
using System.Data;
using System.Data.SqlClient;
namespace Coofucoo.Core
{
/// <summary>
/// DbObject is the class from which all classes in the Data Services
/// Tier inherit. The core functionality of establishing a connection
/// with the database and executing simple stored procedures is also
/// provided by this base class.
/// </summary>
public abstract class DbObject
{
protected SqlConnection Connection;
private string connectionString;
/// <summary>
/// A parameterized constructor, it allows us to take a connection
/// string as a constructor argument, automatically instantiating
/// a new connection.
/// </summary>
/// <param name="newConnectionString">Connection String to the associated database</param>
public DbObject( string newConnectionString )
{
connectionString = newConnectionString;
Connection = new SqlConnection( connectionString );
}
/// <summary>
/// Protected property that exposes the connection string
/// to inheriting classes. Read-Only.
/// </summary>
protected string ConnectionString
{
get
{
return connectionString;
}
}
/// <summary>
/// Private routine allowed only by this base class, it automates the task
/// of building a SqlCommand object designed to obtain a return value from
/// the stored procedure.
/// </summary>
/// <param name="storedProcName">Name of the stored procedure in the DB, eg. sp_DoTask</param>
/// <param name="parameters">Array of IDataParameter objects containing parameters to the stored proc</param>
/// <returns>Newly instantiated SqlCommand instance</returns>
private SqlCommand BuildIntCommand(string storedProcName, IDataParameter[] parameters)
{
SqlCommand command = BuildQueryCommand( storedProcName, parameters );
command.Parameters.Add( new SqlParameter ( "ReturnValue",
SqlDbType.Int,
4, /* Size */
ParameterDirection.ReturnValue,
false, /* is nullable */
0, /* byte precision */
0, /* byte scale */
string.Empty,
DataRowVersion.Default,
null ));
return command;
}
/// <summary>
/// Builds a SqlCommand designed to return a SqlDataReader, and not
/// an actual integer value.
/// </summary>
/// <param name="storedProcName">Name of the stored procedure</param>
/// <param name="parameters">Array of IDataParameter objects</param>
/// <returns></returns>
private SqlCommand BuildQueryCommand(string storedProcName, IDataParameter[] parameters)
{
SqlCommand command = new SqlCommand( storedProcName, Connection );
command.CommandType = CommandType.StoredProcedure;
foreach (SqlParameter parameter in parameters)
{
command.Parameters.Add( parameter );
}
return command;
}
/// <summary>
/// Runs a stored procedure, can only be called by those classes deriving
/// from this base. It returns an integer indicating the return value of the
/// stored procedure, and also returns the value of the RowsAffected aspect
/// of the stored procedure that is returned by the ExecuteNonQuery method.
/// </summary>
/// <param name="storedProcName">Name of the stored procedure</param>
/// <param name="parameters">Array of IDataParameter objects</param>
/// <param name="rowsAffected">Number of rows affected by the stored procedure.</param>
/// <returns>An integer indicating return value of the stored procedure</returns>
protected int RunProcedure(string storedProcName, IDataParameter[] parameters, out int rowsAffected )
{
int result;
Connection.Open();
SqlCommand command = BuildIntCommand( storedProcName, parameters );
rowsAffected = command.ExecuteNonQuery();
result = (int)command.Parameters["ReturnValue"].Value;
Connection.Close();
return result;
}
/// <summary>
/// Will run a stored procedure, can only be called by those classes deriving
/// from this base. It returns a SqlDataReader containing the result of the stored
/// procedure.
/// </summary>
/// <param name="storedProcName">Name of the stored procedure</param>
/// <param name="parameters">Array of parameters to be passed to the procedure</param>
/// <returns>A newly instantiated SqlDataReader object</returns>
protected SqlDataReader RunProcedure(string storedProcName, IDataParameter[] parameters )
{
SqlDataReader returnReader;
Connection.Open();
SqlCommand command = BuildQueryCommand( storedProcName, parameters );
command.CommandType = CommandType.StoredProcedure;
returnReader = command.ExecuteReader();
//Connection.Close();
return returnReader;
}
/// <summary>
/// Creates a DataSet by running the stored procedure and placing the results
/// of the query/proc into the given tablename.
/// </summary>
/// <param name="storedProcName"></param>
/// <param name="parameters"></param>
/// <param name="tableName"></param>
/// <returns></returns>
protected DataSet RunProcedure(string storedProcName, IDataParameter[] parameters, string tableName )
{
DataSet dataSet = new DataSet();
Connection.Open();
SqlDataAdapter sqlDA = new SqlDataAdapter();
sqlDA.SelectCommand = BuildQueryCommand( storedProcName, parameters );
sqlDA.Fill( dataSet, tableName );
Connection.Close();
return dataSet;
}
/// <summary>
/// Takes an -existing- dataset and fills the given table name with the results
/// of the stored procedure.
/// </summary>
/// <param name="storedProcName"></param>
/// <param name="parameters"></param>
/// <param name="dataSet"></param>
/// <param name="tableName"></param>
/// <returns></returns>
protected void RunProcedure(string storedProcName, IDataParameter[] parameters, DataSet dataSet, string tableName )
{
Connection.Open();
SqlDataAdapter sqlDA = new SqlDataAdapter();
sqlDA.SelectCommand = BuildIntCommand( storedProcName, parameters );
sqlDA.Fill( dataSet, tableName );
Connection.Close();
}
}
}
Coofucoo.Core.BizObject：商务层类得基类，无任何内容，以后可以添加。
using System;
namespace Coofucoo.Core
{
/// <summary>
/// The class from which all classes in the business tier
/// inherit from.
/// </summary>
public class BizObject
{
public BizObject()
{
}
}
}
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