NetUserEnum API 的封装问题

[Spacesoft]

这个API 的原型如下：

NET_API_STATUS NetUserEnum(
LPCWSTR servername,
DWORD level,
DWORD filter,
LPBYTE *bufptr,
DWORD prefmaxlen,
LPDWORD entriesread,
LPDWORD totalentries,
LPDWORD resume_handle
);

我翻译成这样：

TFnNetUserEnum = function(ServerName: PWideChar;
Level: DWORD;
Filter: DWORD;
Bufptr: PByte;
prefmaxlen: DWORD;
entriesread: PDWORD;
totalentries: PDWORD;
resume_handle: PDWORD
): DWORD; stdcall;

然后是这样使用的：
var
fnNetUserEnum: TFnNetUserEnum;
hNetAPI32: THandle;
wszBuff: array[1..256] of WideChar;
nStatus: Integer;
pBuffer: PUSER_INFO_1;
dwPrefMaxLen: DWORD;
dwEntriesRead: DWORD;
dwTotalEntries: DWORD;
dwResumeHandle: DWORD;
begin
hNetAPI32 := LoadLibrary('NETAPI32.DLL');

@fnNetApiBufferFree := GetProcAddress(hNetAPI32, 'NetApiBufferFree');

nStatus := fnNetUserEnum(@wszBuff, 1, FILTER_NORMAL_ACCOUNT,
PByte(pBuffer),
dwPrefMaxLen,
@dwEntriesRead,
@dwTotalEntries,
@dwResumeHandle
);
end;

结果调用到nStatus := fnNetUserEnum(...)这句时一直说我
"Write of address 0000000"，是NETAPI32.DLL 出错。

请问是怎么回事呢？

[aiirii]

function NetUserEnum(ServerName: PWideChar;
Level,
Filter: DWord;
var Buffer: Pointer;
PrefMaxLen: DWord;
var EntriesRead,
TotalEntries,
ResumeHandle: DWord): LongWord;stdcall;

@wszBuff 如果是没有赋值, 就用nil;
后面的, 不要用 @;

[Spacesoft]

哦哦哦，多谢提醒^_^

原来LPBYTE *bufptr是Pointer of Pointer，没注意到，谢谢了^_^