程序代码：

public partial class Savewendang : Form
    {
        private SqlConnection con = null;//数据库连接
        private SqlCommand cmd = null;//数据库操作
        private BinaryReader read = null;//二进制读取
        private long fileSize = 0;//文件大小
        private string fileName = null;//文件名字
        private string fileType = null;//文件类型
        private byte[] files;//文件

        SqlBaseClass G_SqlExecute = new SqlBaseClass();
[local]1[/local]
        GoodsIn f = new GoodsIn();
        public Savewendang(GoodsIn f)
        {
            this.f = f;
            InitializeComponent();
        }

        private void Savewendang_Load(object sender, EventArgs e)
        {

        }

        private void selectFileButton_Click(object sender, EventArgs e)//选择文件
        {
            try
            {
                //打开对话框
                OpenFileDialog dialog = new OpenFileDialog();
                if (dialog.ShowDialog() == DialogResult.OK)
                {
                    fileAddress.Text = dialog.FileName;
                    FileInfo info = new FileInfo(@fileAddress.Text);
                    //获得文件大小
                    fileSize = info.Length;
                    //提取文件名,三步走
                    int index = info.FullName.LastIndexOf(".");
                    fileName = info.FullName.Remove(index);
                    fileName = fileName.Substring(fileName.LastIndexOf(@"\") + 1);
                    //获得文件扩展名
                    fileType = info.Extension.Replace(".", "");
                    //把文件转换成二进制流
                    files = new byte[Convert.ToInt32(fileSize)];
                    FileStream file = new FileStream(fileAddress.Text, FileMode.Open, FileAccess.Read);
                    read = new BinaryReader(file);
                    read.Read(files, 0, Convert.ToInt32(fileSize));
                }


            }
            catch (Exception ex)
            {
                MessageBox.Show("选择文件时候发生了　　" + ex.Message);
            }
        }

        private void saveFileButton_Click(object sender, EventArgs e)//保存
        {

          try
            {
                con = G_SqlExecute.GetCon();
                cmd = con.CreateCommand();
                 = "insert into tb_wendang (ps_no,fname,wenjian) values (@ps_no,@fname,@files)";
            }
            catch (Exception ex)
            {
                MessageBox.Show("连接数据库错误" + ex.Message);
            }
            if (fileAddress.Text.Length <= 0)
            {
                MessageBox.Show(this, "请选择一个文件", "文件地址不合法", MessageBoxButtons.OK, MessageBoxIcon.Information, MessageBoxDefaultButton.Button1, MessageBoxOptions.RtlReading);
                return;
            }
            try
            {
                cmd.Parameters.Clear();
                cmd.Parameters.AddWithValue("@fname", fileName);
                cmd.Parameters.AddWithValue("@files", files);
                cmd.Parameters.AddWithValue("@ps_no", PropertyClass.GetGoodsID);
               if (fileSize > 0)
                {
                   string[] type = { "pdf" };
                    bool exists = ((IList)type).Contains(fileType.ToLower());

                    if (!exists)
                    {
                        MessageBox.Show("文档格式不对！只能为pdf格式。", "提示对话框", MessageBoxButtons.OK, MessageBoxIcon.Information);
                        return;
                    }
                }
                string strsql = "select * from tb_wendang where ps_no='" + PropertyClass.GetGoodsID + "' and fname='" + fileName + "'";
                SqlDataReader u = G_SqlExecute.GetReader(strsql);
                u.Read();
                if (u.HasRows)
                {
                    MessageBox.Show(" 已存在名为" + fileName + "的文档");
                    return;
                }
                if (cmd.ExecuteNonQuery() > 0)
                {
                    MessageBox.Show(fileName + " 保存成功!");
                }
                else
                {
                    MessageBox.Show("发生错误!!");
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show("保存 " + fileName + " 时候发生了　　" + ex.Message);
            }
        }
    }
}