关于WinCE数据库API的代码问题

wdzywl

关于WinCE数据库API的代码问题 [复制链接]

HANDLE g_hDB;
CEOID g_oidDB;
int g_nLastSort = PID_NAME;


(1)
static HANDLE OpenCreateDB(HWND hWnd, int * pnRecords)
{
        int i, rc;
        CEOIDINFO oidinfo;
        SORTORDERSPEC sos[4];

        g_oidDB = 0;
        g_hDB = CeOpenDatabase(&g_oidDB, TEXT("\\Albums"), g_nLastSort, 0, hWnd);

        if(g_hDB == INVALID_HANDLE_VALUE)
        {
                rc = GetLastError();

                if(rc == ERROR_FILE_NOT_FOUND)
                {
                        i=0;
                        sos.propid = PID_NAME;
                        sos[i++].dwFlags = 0;

                        sos.propid = PID_ARTIST;
                        sos[i++].dwFlags = 0;               

                        sos.propid = PID_CATEGORY;
                        sos[i++].dwFlags = 0;               

                        g_oidDB = CeCreateDatabase(TEXT("\\Albums"), 0, 3, sos);

                        if(!g_oidDB)
                        {
                                TCHAR szErr[100];

                                wsprintf(szErr, TEXT("Database create failed. rc %d"), GetLastError());

                                MessageBox(hWnd, szErr, szAppName, MB_OK);

                                return 0;
                        }

                        g_hDB = CeOpenDatabase(&g_oidDB, NULL, g_nLastSort, 0, hWnd);
                }
        }

        CeOidGetInfo(g_oidDB, &oidinfo);
        *pnRecords = oidinfo.infDatabase.wNumRecords;

        return g_hDB;
}

上面这个函数我尝试去打开一个database,如果不存在,则创建一个.
但是在编译时却返回如下错误:
.\AlbumDB.cpp(44) : error C4995: 'CeOpenDatabase': name was marked as #pragma deprecated
.\AlbumDB.cpp(62) : error C4995: 'CeCreateDatabase': name was marked as #pragma deprecated
.\AlbumDB.cpp(75) : error C4995: 'CeOpenDatabase': name was marked as #pragma deprecated
实在弄不清楚为什么?


(2)
static LPARAM DoMainCommandEdit(HWND hWnd, WORD idItem, HWND hwndCtl, WORD wNotifyCode)
{
        PCEPROPVAL pcepv = 0;
        int nSel, rc;
        WORD wProps = 0;
        DWORD dwRecSize, dwIndex;
        CEOID oid;

        oid = CeReadRecordProps(g_hDB, CEDB_ALLOWREALLOC, &wProps, NULL, &((LPBYTE)pcepv), &dwRecSize);
        if(!oid)
        {
                TCHAR szTxt[64];

                rc = GetLastError();
                wsprintf(szTxt, TEXT("DB item not read. rc = %d(%x)."), rc, rc);

                MessageBox(hWnd, szTxt, TEXT("Error"), MB_OK);
                return 0;
        }
}

这个函数我是想编译一个数据项,只把问题代码列出了.
编译时发生如下错误:
.\AlbumDB.cpp(650) : error C2102: '&' requires l-value
不清楚为什么?



麻烦高手帮忙看看这两个问题吧! 谢谢了!!!

sje251

1\可以使用
#pragma   warning(   disable:4995   )   //   disable   deprecated   warning
来去掉warning
不过应该是需要换一个api CeOpenDatabaseEx2
2\ PCEPROPVAL pcepv = 0; 是个空指针，需要分配一个实体

bb_008

感谢
第一个问题解决了

但是第二个问题仍然存在
我查了windows mobile 6 sdk关于CeReadRecordProps()函数的说明:
lplpBuffer
[out] Pointer to a long pointer to a buffer that receives the requested properties. If the dwFlags parameter includes the CEDB_ALLOWREALLOC flag, the buffer may be reallocated if necessary. If the CEDB_ALLOWREALLOC flag is specified and this parameter is NULL, the server uses the LocalAlloc function to allocate a buffer of the appropriate size in the caller's address space and returns a pointer to the buffer. Note that if the CEDB_ALLOWREALLOC flag is specified, it is possible for the value of this pointer to change even on failure. For example, the old memory might be freed and the allocation might then fail, leaving the pointer set to NULL.


就是说允许这个参数指针是空指针,会自行调用LocalAlloc()申请内存的.
即使我在改为这样:

pcepv = (PCEPROPVAL)LocalAlloc(LPTR, sizeof(CEPROPVAL));
oid = CeReadRecordProps(g_hDB, CEDB_ALLOWREALLOC, &wProps, NULL, &((LPBYTE)pcepv), &dwRecSize);

仍然编译不过,还是那个错误.

求教!
谢谢了!!!

tuwen

try:

LPBYTE pcepv = NULL;
oid = CeReadRecordProps(g_hDB, CEDB_ALLOWREALLOC, &wProps, NULL, &pcepv, &dwRecSize);  

iqtao

谢谢
问题解决了