怎样做sqlserver数据库的还原

以下为引用的内容：
  void restoreButton_Click(object sender, System.EventArgs e)
   {
    string path = pathTextBox.Text;
    string dbname = dbDropDownList.SelectedValue;

    string restoreSql = "use master;";
    restoreSql = "restore database @dbname from disk = @path;";
                string pai = "use master;ALTER DATABASE Wy SET OFFLINE WITH ROLLBACK IMMEDIATE;ALTER DATABASE Wy SET ONLINE WITH ROLLBACK IMMEDIATE";
                SqlConnection cOnn= new SqlConnection(ConnStr);
                SqlCommand com1 = new SqlCommand(pai, conn);

    SqlCommand myCommand = new SqlCommand(restoreSql, new SqlConnection(ConnStr));

    myCommand.Parameters.Add("@dbname", SqlDbType.Char);
    myCommand.Parameters["@dbname"].Value = dbname;
    myCommand.Parameters.Add("@path", SqlDbType.Char);
    myCommand.Parameters["@path"].Value = path;

    try
    {
                    conn.Open();
                    com1.ExecuteNonQuery();
                    conn.Close();
                    myCommand.Connection.Open();
     myCommand.ExecuteNonQuery();
                    infoLabel.Text = "恢复成功！
已经把备份" path "恢复到数据库";

    }
    catch(Exception ex)
    {
                    infoLabel.Text = "恢复失败！
出错信息如下：
" ex.ToString();
    }
    finally
    {
     myCommand.Connection.Close();

    }
   }