C#实现文件与二进制互转并存入数据库

//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();
       
    }