//這個方法是瀏覽文件對象    private void button1_Click(object sender, EventArgs e)    {      //用戶打開文件瀏覽      using (OpenFileDialog dialog = new OpenFileDialog())      {        //只能單選一個文件        dialog.Multiselect = false;        //選擇一個文件        if (dialog.ShowDialog() == DialogResult.OK)        {          try          {            //把選擇的文件路徑給txtPath            this.textBox1.Text = dialog.FileName;          }          catch (Exception ex)          {            //拋出異常            throw (ex);          }        }      }    }    //關閉    private void button3_Click(object sender, EventArgs e)    {      this.Close();    }    //把文件轉成二進制流出入數據庫    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('測試文件',@file)";      SqlCommand mycomm = new SqlCommand(str, myconn);      mycomm.Parameters.Add("@file", SqlDbType.Binary, byData.Length);      mycomm.Parameters["@file"].Value = byData;      mycomm.ExecuteNonQuery();      myconn.Close();    }    //從數據庫中把二進制流讀出寫入還原成文件    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='測試文件' ";      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();           }