C# 文件与二进制互转数据库写入读出

 //这个方法是浏览文件对象
        private void button1_Click(object sender, EventArgs e)
        {
            //用户打开文件浏览
            using (OpenFileDialog dialog = new OpenFileDialog())
            {
                //只能单选一个文件
                dialog.Multiselect = false;
                //选择一个文件
                if (dialog.ShowDialog() == DialogResult.OK)
                {
                    try
                    {
                        //把选择的文件路径给txtPath
                        this.textBox1.Text = dialog.FileName;
                    }
                    catch (Exception ex)
                    {
                        //抛出异常
                        throw (ex);
                    }
                }
            }
        }

        //关闭
        private void button3_Click(object sender, EventArgs e)
        {
            this.Close();
        }

        //把文件转成二进制流出入数据库
        private void button2_Click(object sender, EventArgs e)
        {
            FileStream fs = new FileStream(textBox1.Text, FileMode.Open);
            BinaryReader br = new BinaryReader(fs);
            Byte[] byData = br.ReadBytes((int)fs.Length);
            fs.Close();
            string conn = "server=.;database=testDB;Uid=sa;Pwd=sa ";
            SqlConnection myconn = new SqlConnection(conn);
            myconn.Open();
            string str = "insert into pro_table (pro_name,pro_file) values('测试文件',@file)";
            SqlCommand mycomm = new SqlCommand(str, myconn);
            mycomm.Parameters.Add("@file", SqlDbType.Binary, byData.Length);
            mycomm.Parameters["@file"].Value = byData;
            mycomm.ExecuteNonQuery();
            myconn.Close();
        }

        //从数据库中把二进制流读出写入还原成文件
        private void button4_Click(object sender, EventArgs e)
        {
            string conn = "server=.;database=testDB;Uid=sa;Pwd=sa ";
            string str = "select pro_file from pro_table where pro_name='测试文件' ";
            SqlConnection myconn = new SqlConnection(conn);
            SqlDataAdapter sda = new SqlDataAdapter(str, conn);
            DataSet myds = new DataSet();
            myconn.Open();
            sda.Fill(myds);
            myconn.Close();
            Byte[] Files = (Byte[])myds.Tables[0].Rows[0]["pro_file"]; 
            BinaryWriter bw = new BinaryWriter(File.Open("D:\2.rdlc",FileMode.OpenOrCreate));
            bw.Write(Files);
            bw.Close();
              
        }