尝试从文件服务器检索大量打开文件会返回ERROR_MORE_DATA值(错误号234),但在处理一小部分文件时似乎工作正常(似乎返回大约84个条目)。此代码基于以下示例:http://pinvoke.net/default.aspx/netapi32/NetFileEnum.html
我发现的大多数示例都没有涉及如何处理大量文件。根据我的理解,这与resume_handle有关,但是我不确定需要做什么。我是否需要以某种方式在循环中调用此方法?
代码如下:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading.Tasks;
namespace OpenFiles
{
class Program
{
public static string computername = "computername";
static void Main(string[] args)
{
List<string> theFileList = NativeMethods.GetFiles(computername);
foreach (string file in theFileList)
{
Console.WriteLine(file);
}
}
}
static class NativeMethods
{
[DllImport("netapi32.dll", SetLastError = true, CharSet = CharSet.Unicode)]
static extern int NetFileEnum(
string servername,
string basepath,
string username,
int level,
ref IntPtr bufptr,
int prefmaxlen,
out int entriesread,
out int totalentries,
IntPtr resume_handle
);
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
struct FILE_INFO_3
{
public int fi3_id;
public int fi3_permission;
public int fi3_num_locks;
[MarshalAs(UnmanagedType.LPWStr)]
public string fi3_pathname;
[MarshalAs(UnmanagedType.LPWStr)]
public string fi3_username;
}
[DllImport("Netapi32.dll", SetLastError = true)]
static extern int NetApiBufferFree(IntPtr Buffer);
public static List<string> GetFiles(string Computername)
{
const int MAX_PREFERRED_LENGTH = -1;
int dwReadEntries;
int dwTotalEntries;
IntPtr pBuffer = IntPtr.Zero;
FILE_INFO_3 pCurrent = new FILE_INFO_3();
List<string> fileList = new List<string>();
int dwStatus = NetFileEnum(Computername, null, null, 3, ref pBuffer, MAX_PREFERRED_LENGTH, out dwReadEntries, out dwTotalEntries, IntPtr.Zero);
if (dwStatus == 0)
{
for (int dwIndex = 0; dwIndex < dwReadEntries; dwIndex++)
{
IntPtr iPtr = new IntPtr(pBuffer.ToInt32() + (dwIndex * Marshal.SizeOf(pCurrent)));
pCurrent = (FILE_INFO_3)Marshal.PtrToStructure(iPtr, typeof(FILE_INFO_3));
string fileInfo = pCurrent.fi3_id + "," +
pCurrent.fi3_num_locks + "," +
pCurrent.fi3_pathname + "," +
pCurrent.fi3_permission + "," +
pCurrent.fi3_username;
fileList.Add(fileInfo);
}
NetApiBufferFree(pBuffer);
}
else
{
Console.WriteLine("error: " + dwStatus);
}
return fileList;
}
}
}
答案 0 :(得分:0)
在我有限的经验中,大量的结果可能比最大缓冲区大。在这种情况下,会给出更多的数据响应,并指示我们使用提供的简历句柄再次调用。在您的示例中,不会更改resume句柄,因为DllImport签名未将其定义为out参数。使用第一次调用的恢复句柄结果(传递零意味着第一次调用)允许您接收下一批次。循环直到收到成功回复或其他错误。
请务必解决定义NetFileEnum签名的问题。 恢复句柄未定义为out,因此无法通过被调用函数进行更改。
请尝试使用以下DLL导入签名:
[DllImport("netapi32.dll", SetLastError = true, CharSet = CharSet.Unicode)]
static extern int NetFileEnum(
string servername,
string basepath,
string username,
int level,
ref IntPtr bufptr,
int prefmaxlen,
out int entriesread,
out int totalentries,
out IntPtr resume_handle
);
当您获得更多数据响应时,您应该能够多次使用生成的简历句柄重新调用NetFileEnum。