SqlConnection con = new SqlConnection("Data Source=.;;Initial Catalog=DB_Test;User ID=sa;Password=sa");
            string sql = "backup database DB_Test to disk= ‘c:\\aVb.bak‘";
            con.Open();
            if (!File.Exists("c:\\aa.bak"))
            {
                SqlCommand com = new SqlCommand(sql, con);
                com.ExecuteNonQuery();      //执行sql语句   
                lblmessage.Text = "系统信息：备份成功！";
            }
            else
            {
                lblmessage.Text = "系统信息：文件已存在！";
            } 

            //引用SQLDMO.dll，SQLDMO由Microsoft   SQL   Server自带的SQLDMO.dll提供，SQLDMO.dll是一个COM对象
            SQLDMO.SQLServer svr = new SQLDMO.SQLServerClass();
            try
            {
                svr.Connect("192.168.89.20", "sa", "Aa123456");
                //取得所有的进程列表
                SQLDMO.QueryResults qr = svr.EnumProcesses(-1);
                int iColPIDNum = -1;
                int iColDbName = -1;
                //找到和要恢复数据库相关的进程
                for (int i = 1; i <= qr.Columns; i++)
                {
                    string strName = qr.get_ColumnName(i);
                    if (strName.ToUpper().Trim() == "SPID")
                    {
                        iColPIDNum = i;
                    }
                    else if (strName.ToUpper().Trim() == "DBNAME")
                    {
                        iColDbName = i;
                    }
                    if (iColPIDNum != -1 && iColDbName != -1)
                        break;
                }
                //将相关进程杀死
                for (int i = 1; i <= qr.Rows; i++)
                {
                    int lPID = qr.GetColumnLong(i, iColPIDNum);
                    string strDBName = qr.GetColumnString(i, iColDbName);
                    if (strDBName.ToUpper() == strDbName.ToUpper())
                        svr.KillProcess(lPID);
                }

                SQLDMO.Restore res = new SQLDMO.RestoreClass();

                res.Action = SQLDMO.SQLDMO_RESTORE_TYPE.SQLDMORestore_Database;
                res.Files = strFileName;

                res.Database = strDbName;
                res.FileNumber = 1;

                res.ReplaceDatabase = true;
                res.SQLRestore(svr);

                return true;
            }
            catch (Exception err)
            {
                //throw (new Exception("" + err.Message));
               MessageBox.Show("恢复数据库失败,请关闭所有和该数据库连接的程序！" + err.Message);
                return false;
            }
            finally
            {
                svr.DisConnect();
            }