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 = "恢復(fù)成功！<br>已經(jīng)把備份"+path+"恢復(fù)到數(shù)據(jù)庫(kù)";

    }
    catch(exception ex)
    {
                    infolabel.text = "恢復(fù)失敗！<br>出錯(cuò)信息如下：<br>" + ex.tostring();
    }
    finally
    {
     mycommand.connection.close();

    }
   }