c#继承类问题

Question

public virtual ADODB.Properties ADODB.Properties { [return: MarshalAs(UnmanagedType.Interface)] [MethodImpl(MethodImplOptions.InternalCall, MethodCodeType=MethodCodeType.Runtime), DispId(500)] get; }为什么c#编译的时候报告：修饰符“public”对该项无效
急，在线等

Answer 1

namespace ADODB
{
    using System;
    using System.Reflection;
    using System.Runtime.CompilerServices;
    using System.Runtime.InteropServices;    [ComImport, Guid("00000514-0000-0010-8000-00AA006D2EA4"), ClassInterface((short) 0), ComSourceInterfaces("ADODB.ConnectionEvents\0"), TypeLibType((short) 6), DefaultMember("ConnectionString")]
    public class ConnectionClass : _Connection, Connection, ConnectionEvents_Event
    {
     public event ConnectionEvents_BeginTransCompleteEventHandler BeginTransComplete;        public event ConnectionEvents_CommitTransCompleteEventHandler CommitTransComplete;        public event ConnectionEvents_ConnectCompleteEventHandler ConnectComplete;        public event ConnectionEvents_DisconnectEventHandler Disconnect;        public event ConnectionEvents_ExecuteCompleteEventHandler ExecuteComplete;        public event ConnectionEvents_InfoMessageEventHandler InfoMessage;        public event ConnectionEvents_RollbackTransCompleteEventHandler RollbackTransComplete;        public event ConnectionEvents_WillConnectEventHandler WillConnect;        public event ConnectionEvents_WillExecuteEventHandler WillExecute;        [MethodImpl(MethodImplOptions.InternalCall, MethodCodeType=MethodCodeType.Runtime), DispId(7)]
        public virtual extern int BeginTrans();
        [MethodImpl(MethodImplOptions.InternalCall, MethodCodeType=MethodCodeType.Runtime), DispId(0x15)]
        public virtual extern void Cancel();
        [MethodImpl(MethodImplOptions.InternalCall, MethodCodeType=MethodCodeType.Runtime), DispId(5)]
        public virtual extern void Close();
        [MethodImpl(MethodImplOptions.InternalCall, MethodCodeType=MethodCodeType.Runtime), DispId(8)]
        public virtual extern void CommitTrans();
        [return: MarshalAs(UnmanagedType.Interface)]
        [MethodImpl(MethodImplOptions.InternalCall, MethodCodeType=MethodCodeType.Runtime), DispId(6)]
        public virtual extern Recordset Execute([In, MarshalAs(UnmanagedType.BStr)] string CommandText, [Optional, MarshalAs(UnmanagedType.Struct)] out object RecordsAffected, [In, Optional, DefaultParameterValue(-1)] int Options);
        [MethodImpl(MethodImplOptions.InternalCall, MethodCodeType=MethodCodeType.Runtime), DispId(10)]
        public virtual extern void Open([In, Optional, DefaultParameterValue(""), MarshalAs(UnmanagedType.BStr)] string ConnectionString, [In, Optional, DefaultParameterValue(""), MarshalAs(UnmanagedType.BStr)] string UserID, [In, Optional, DefaultParameterValue(""), MarshalAs(UnmanagedType.BStr)] string Password, [In, Optional, DefaultParameterValue(-1)] int Options);
        [return: MarshalAs(UnmanagedType.Interface)]
        [MethodImpl(MethodImplOptions.InternalCall, MethodCodeType=MethodCodeType.Runtime), DispId(0x13)]
        public virtual extern Recordset OpenSchema([In] SchemaEnum Schema, [In, Optional, MarshalAs(UnmanagedType.Struct)] object Restrictions, [In, Optional, MarshalAs(UnmanagedType.Struct)] object SchemaID);
        [MethodImpl(MethodImplOptions.InternalCall, MethodCodeType=MethodCodeType.Runtime), DispId(9)]
        public virtual extern void RollbackTrans();[DispId(4)]
        public virtual string ADODB._Connection.Version { [return: MarshalAs(UnmanagedType.BStr)] [MethodImpl(MethodImplOptions.InternalCall, MethodCodeType=MethodCodeType.Runtime), DispId(4)] get; }    //修饰符public对该项无效
[DispId(0x3e8)]
        public virtual PositionEnum ADODB._Recordset.AbsolutePosition { [MethodImpl(MethodImplOptions.InternalCall, MethodCodeType=MethodCodeType.Runtime), DispId(0x3e8)] get; [param: In] [MethodImpl(MethodImplOptions.InternalCall, MethodCodeType=MethodCodeType.Runtime), DispId(0x3e8)] set; }   //修饰符public对该项无效   ....     
        
 [DispId(500)]
        public virtual ADODB.Properties Properties { [return: MarshalAs(UnmanagedType.Interface)] [MethodImpl(MethodImplOptions.InternalCall, MethodCodeType=MethodCodeType.Runtime), DispId(500)] get; }    //正常... 
      }
    }
}

Answer 2

public  ConnectionClass()
{
}
加多这句上去看看!

Answer 3

你的意思是把 public class ConnectionClass : _Connection, Connection, ConnectionEvents_Event
{
}
换成 public ConnectionClass : _Connection, Connection, ConnectionEvents_Event
{
}
？