C# Access 二进制文件读写

using System;
using System.Data;
using System.Configuration;
using System.Data.OleDb;
using System.Collections;
using System.Windows.Forms;

namespace AccessOperator
{
public class AccessHelper
{
#region 属性
private OleDbConnection conn;
// private OleDbCommand cmd;
#endregion

#region 打开Access
/// <summary>
/// 打开连接
/// </summary>
/// <param name="AccessPath">完整路径，//</param>
/// <param name="UserName">无用户名，则参数为""</param>
/// <param name="UserPWD">无密码，则参数为""</param>
public AccessHelper(string AccessPath, string UserName, string UserPWD)
{
try
{
//组成数据库连接字符串
string ConnStr = "Provider=Microsoft.Jet.OLEDB.4.0; Data Source=" + AccessPath + ";";
if (UserName != string.Empty && UserPWD != string.Empty)
{
ConnStr += "User Id=" + UserName + "; Password=" + UserPWD + ";";
}
conn = new OleDbConnection(ConnStr);
conn.Open();
if (conn.State != ConnectionState.Open)
{
MessageBox.Show("数据库连接异常");
}
}
catch (Exception ex)
{
MessageBox.Show("数据库连接异常，请确保Access文件存在，用户名、密码正确");
}
}
#endregion

/// <summary>
/// 返回受影响的行数
/// </summary>
/// <param name="cmdText">SQL 语句</param>
/// <returns>返回受影响的函数</returns>
public int ExecuteNonQuery(string cmdText)
{
OleDbCommand cmd = new OleDbCommand();
PrepareCommand(cmd, conn, cmdText);
try
{
int count = cmd.ExecuteNonQuery();
return count;
}
catch
{
conn.Close();
throw;
}
}

// 返回一个DataReader对象
public OleDbDataReader ExecuteReader(string cmdText)
{
//创建一个SqlCommand对象
OleDbCommand cmd = new OleDbCommand();
PrepareCommand(cmd, conn, cmdText);
try
{
OleDbDataReader reader = cmd.ExecuteReader();
return reader;
}
catch
{
conn.Close();
throw;
}
}

// 返回数据集
public DataSet ExecuteDataSet(string cmdText)
{
//创建一个SqlCommand对象，并对其进行初始化
OleDbCommand cmd = new OleDbCommand();
PrepareCommand(cmd, conn, cmdText);
OleDbDataAdapter da = new OleDbDataAdapter(cmd);
DataSet ds = new DataSet();
try
{
//填充ds
da.Fill(ds);
return ds;
}
catch
{
conn.Close();
throw;
}
}

//返回结果集的第一列
public object ExecuteScalar(string cmdText)
{
OleDbCommand cmd = new OleDbCommand();
PrepareCommand(cmd, conn, cmdText);
object val = cmd.ExecuteScalar();
return val;
}

// 执行SQL前的准备
private void PrepareCommand(OleDbCommand cmd, OleDbConnection conn, string cmdText)
{
//判断连接的状态。如果是关闭状态，则打开
if (conn.State != ConnectionState.Open)
conn.Open();
//cmd属性赋值
cmd.Connection = conn;
cmd.CommandText = cmdText;
cmd.CommandType = CommandType.Text;
//添加cmd需要的存储过程参数
}

#region - 二进制文件用，不操作文件系统时可以删除 -
//二进制文件的保存
//表的结构:三列，Title、Description、nr，类型分别为， 文本 文本 Ole对象
public void SaveBinaryData(string strFileName, string strHD, string strZH, string strPic)
{
System.IO.FileStream fs = new System.IO.FileStream(strFileName, System.IO.FileMode.Open);
System.IO.BinaryReader br = new System.IO.BinaryReader(fs);
byte[] buffer = br.ReadBytes((int)fs.Length);
OleDbCommand command = new OleDbCommand("INSERT INTO 图形绘制知识库(巷道类型,支护类型,图形类型,绘图知识)" +
"VALUES (@HDStyle,@ZHMode,@PicType,@nr)", conn);

command.Parameters.AddWithValue("@HDStyle", strHD);
command.Parameters.AddWithValue("@ZHMode",  strZH);
command.Parameters.AddWithValue("@PicType", strPic);
command.Parameters.AddWithValue("@nr", buffer);

command.ExecuteNonQuery();
br.Close();
fs.Close();
MessageBox.Show("保存完毕。");
OleDbCommand cmd = new OleDbCommand();
}

/// <summary>
/// 导出二进制数据
/// </summary>
/// <param name="strFileName">文件名称，表中第一个字段</param>
/// <param name="strSavePath">文件保存路径，全路径</param>
public void ExportBinaryData(string strSavePath, string strHD, string strZH, string strPic)
{
//构建数据库连接，SQL语句，创建参数
OleDbCommand command = new OleDbCommand("select top 1 * from 图形绘制知识库 where 巷道类型 = \"" + strHD + "\" and 支护类型 = \"" + strZH + "\" and 图形类型 = \"" + strPic + "\"", conn);
OleDbDataReader dr = command.ExecuteReader();
byte[] buff = null;
if (dr.Read())
{
buff = (byte[])dr["绘图知识"];
}

if (System.IO.File.Exists(strSavePath))
System.IO.File.Delete(strSavePath);

System.IO.FileStream stream = new System.IO.FileStream(strSavePath, System.IO.FileMode.CreateNew, System.IO.FileAccess.Write);
System.IO.BinaryWriter bw = new System.IO.BinaryWriter(stream);
bw.Write(buff);
bw.Close();
stream.Close();
MessageBox.Show("生成完毕。");
}
#endregion

// 关闭连接、释放资源
public void CloseConn()
{
if (conn.State == ConnectionState.Open)
{
conn.Close();
conn.Dispose();
}
}
}
}

完整代码：在Office 2007，W2k3 SP2，VS2008 SP1下测试通过

using System;
using System.ComponentModel;
using System.Data;
using System.Data.OleDb;
using System.Drawing;
using System.IO;
using System.Text;
using System.Windows.Forms;

namespace WindowsFormsApplication7
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}

private string strCnn = @"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=E:\c\WindowsFormsApplication7\aspxWeb.mdb;Persist Security Info=True";
private void button2_Click(object sender, EventArgs e)
{
if (this.openFileDialog1.ShowDialog() == DialogResult.OK)
{
this.textBox1.Text = this.openFileDialog1.FileName;
}
}

private void button1_Click(object sender, EventArgs e)
{
if (this.textBox1.Text.Equals(String.Empty))
{
MessageBox.Show("先选择文件。");
return;
}

FileStream fs = new FileStream(this.textBox1.Text, FileMode.Open);
BinaryReader br = new BinaryReader(fs);
byte[] buffer = br.ReadBytes((int)fs.Length);
OleDbConnection myConnection = new OleDbConnection(strCnn);
OleDbCommand command = new OleDbCommand("INSERT INTO TestTable (Title,Description,nr)" +
"VALUES (@Title,@Description,@nr)", myConnection);

command.Parameters.AddWithValue("@Title", "a");
command.Parameters.AddWithValue("@Description", "mengxianhui@dotnet.aspx.cc");
command.Parameters.AddWithValue("@nr", buffer);

//打开连接，执行查询
myConnection.Open();
command.ExecuteNonQuery();
myConnection.Close();
br.Close();
fs.Close();
MessageBox.Show("保存完毕。");
}

private void button3_Click(object sender, EventArgs e)
{
//构建数据库连接，SQL语句，创建参数
OleDbConnection myConnection = new OleDbConnection(strCnn);
myConnection.Open();
OleDbCommand command = new OleDbCommand("select top 1 * from TestTable Order By id DESC", myConnection);
OleDbDataReader dr = command.ExecuteReader();
byte[] buff = null;
if (dr.Read())
{
buff = (byte[])dr["nr"];
}

String p = Application.ExecutablePath;
p = p.Substring(0,p.LastIndexOf("\\"));
p +=  "\\m.doc";
this.textBox2.Text = p ;
if (File.Exists(p)) File.Delete(p);
myConnection.Close();
System.IO.FileStream stream = new System.IO.FileStream(p, System.IO.FileMode.CreateNew, System.IO.FileAccess.Write);
System.IO.BinaryWriter bw = new System.IO.BinaryWriter(stream);
bw.Write(buff);
bw.Close();
stream.Close();
MessageBox.Show("生成完毕。");
}
}
}