类型：转载 责任编辑：asp.net 日期：2007/05/23
热门软件下载：
在vc中用ado虽然不是很麻烦但是由于vc没有提供对ado的包装类，象数据感知控件,ADO事件（如记录集的移动事件）等机制都难以在vc下运用和实现，于是乎我在delphi下习惯了的一些运用在vc下都无法做到。。。开发进度非常缓慢，痛苦啊。。。。在网上download 的一些vc运用数据库的例子都做得不伦不类。。。。各位有什么感受也说说啊
网友回答：
资料是满大街都有，看你怎么找了。不太清楚“数据感知”是什么概念，帮不到你，ADO Event倒是多的很。
(以下的例子由 PlatForm SDK 中摘录，请注意。)
// eventmodel.cpp : Defines the entry point for the console application.
//
#import "c:\Program Files\Common Files\System\ADO\msado15.dll" \
no_namespace rename("EOF", "EndOfFile")
#include <comdef.h>
#include <stdio.h>
//----The Connection events----------------------------------------------
class CConnEvent : public ConnectionEventsVt
{
private:
ULONG m_cRef;
public:
CConnEvent() { m_cRef = 0; };
~CConnEvent() {};
STDMETHODIMP QueryInterface(REFIID riid, void ** ppv);
STDMETHODIMP_(ULONG) AddRef(void);
STDMETHODIMP_(ULONG) Release(void);
STDMETHODIMP raw_InfoMessage(
struct Error *pError,
EventStatusEnum *adStatus,
struct _Connection *pConnection);
STDMETHODIMP raw_BeginTransComplete(
LONG TransactionLevel,
struct Error *pError,
EventStatusEnum *adStatus,
struct _Connection *pConnection);
STDMETHODIMP raw_CommitTransComplete(
struct Error *pError,
EventStatusEnum *adStatus,
struct _Connection *pConnection);
STDMETHODIMP raw_RollbackTransComplete(
struct Error *pError,
EventStatusEnum *adStatus,
struct _Connection *pConnection);
STDMETHODIMP raw_WillExecute(
BSTR *Source,
CursorTypeEnum *CursorType,
LockTypeEnum *LockType,
long *Options,
EventStatusEnum *adStatus,
struct _Command *pCommand,
struct _Recordset *pRecordset,
struct _Connection *pConnection);
STDMETHODIMP raw_ExecuteComplete(
LONG RecordsAffected,
struct Error *pError,
EventStatusEnum *adStatus,
struct _Command *pCommand,
struct _Recordset *pRecordset,
struct _Connection *pConnection);
STDMETHODIMP raw_WillConnect(
BSTR *ConnectionString,
BSTR *UserID,
BSTR *Password,
long *Options,
EventStatusEnum *adStatus,
struct _Connection *pConnection);
STDMETHODIMP raw_ConnectComplete(
struct Error *pError,
EventStatusEnum *adStatus,
struct _Connection *pConnection);
STDMETHODIMP raw_Disconnect(
EventStatusEnum *adStatus,
struct _Connection *pConnection);
};
//-----The Recordset events----------------------------------------------
class CRstEvent : public RecordsetEventsVt
{
private:
ULONG m_cRef;
public:
CRstEvent() { m_cRef = 0; };
~CRstEvent() {};
STDMETHODIMP QueryInterface(REFIID riid, void ** ppv);
STDMETHODIMP_(ULONG) AddRef(void);
STDMETHODIMP_(ULONG) Release(void);
STDMETHODIMP raw_WillChangeField(
LONG cFields,
VARIANT Fields,
EventStatusEnum *adStatus,
struct _Recordset *pRecordset);
STDMETHODIMP raw_FieldChangeComplete(
LONG cFields,
VARIANT Fields,
struct Error *pError,
EventStatusEnum *adStatus,
struct _Recordset *pRecordset);
STDMETHODIMP raw_WillChangeRecord(
EventReasonEnum adReason,
LONG cRecords,
EventStatusEnum *adStatus,
struct _Recordset *pRecordset);
STDMETHODIMP raw_RecordChangeComplete(
EventReasonEnum adReason,
LONG cRecords,
struct Error *pError,
EventStatusEnum *adStatus,
struct _Recordset *pRecordset);
STDMETHODIMP raw_WillChangeRecordset(
EventReasonEnum adReason,
EventStatusEnum *adStatus,
struct _Recordset *pRecordset);
STDMETHODIMP raw_RecordsetChangeComplete(
EventReasonEnum adReason,
struct Error *pError,
EventStatusEnum *adStatus,
struct _Recordset *pRecordset);
STDMETHODIMP raw_WillMove(
EventReasonEnum adReason,
EventStatusEnum *adStatus,
struct _Recordset *pRecordset);
STDMETHODIMP raw_MoveComplete(
EventReasonEnum adReason,
struct Error *pError,
EventStatusEnum *adStatus,
struct _Recordset *pRecordset);
STDMETHODIMP raw_EndOfRecordset(
VARIANT_BOOL *fMoreData,
EventStatusEnum *adStatus,
struct _Recordset *pRecordset);
STDMETHODIMP raw_FetchProgress(
long Progress,
long MaxProgress,
EventStatusEnum *adStatus,
struct _Recordset *pRecordset);
STDMETHODIMP raw_FetchComplete(
struct Error *pError,
EventStatusEnum *adStatus,
struct _Recordset *pRecordset);
};
对于要实现事件功能，那的写一个自己的函数了，你可以写一个CADoEvent类在你操作记录的 时候 ，和 数据库连接的时候你发送一个registered message,然后在message 处理函数作你想要做的事情，这样在你移动记录，代开recorder的时候就会触发这个message，你就可以在 message handle 函数中完成你自己的事件，当然你的可以把你的 message handle 函数做成一虚函数，这样你在子类中还可以完成子类的特定函数功能。