COM+ Web 服务：通过复选框路由到 XML Web Services(2) （微软中国）

事务性组件示例
简单的计算器远算不上工作量繁重的业务应用程序，因此我们现在考虑带有对象池的适于 COM+ 事务性组件的应用程序。
最容易管理和配置的组件是由 ServicedComponent 导出的托管代码组件，如以下 C# 示例所示：using System;using System.Reflection;using System.Runtime.InteropServices;using System.EnterpriseServices;using System.Data;using System.Data.SqlClient;[assembly: ApplicationName("SCTrans")][assembly: ApplicationActivation(ActivationOption.Server,    SoapVRoot="SCTrans")][assembly: AssemblyKeyFile("SCTrans.snk")]namespace SCTrans{    public interface ISCTrans    {     string CountUp (string Key);    }    [ObjectPooling(MinPoolSize=0, MaxPoolSize=25)]    [JustInTimeActivation(true)]    [ClassInterface(ClassInterfaceType.AutoDual)]    [TransactionAttribute(TransactionOption.RequiresNew)]    public class SCTransSQLNC : ServicedComponent, ISCTrans    {     [AutoComplete]     public string CountUp (string Key)     {        _command = new SqlCommand("", _connection);        _command.CommandType = CommandType.Text;        _command.Connection.Open();     _command.CommandText = "UPDATE CallCount WITH (ROWLOCK) SET    CallCount = CallCount + 1 WHERE Machine='" + Key + "'";     _command.ExecuteNonQuery();        _command.Connection.Close();     _numcalls++;     return (_numcalls + " NC " + _guid);     }    protected override bool CanBePooled()     {     return true;    }     private int _numcalls = 0;     private string _guid = Guid.NewGuid().ToString();     private SqlConnection _connection =    new SqlConnection("user id=MyUser;password=My!Password;     database=SoapTest;server=MyServer");     private SqlCommand _command;        }}