枚举网络资源

项目
06/13/2023

以下示例演示枚举网络上所有资源的应用程序定义的函数 (EnumerateFunc) 。此示例为指向 NETRESOURCE 结构的指针指定 NULL，因为当 WNetOpenEnum 收到 NULL 指针时，它会检索到网络根的句柄。

若要开始枚举网络容器资源，应用程序应执行以下步骤：

将表示资源的 NETRESOURCE 结构的地址传递给 WNetOpenEnum 函数。
分配一个足够大的缓冲区，以保存 WNetEnumResource 函数返回的 NETRESOURCE 结构的数组，以及其成员指向的字符串。
将 WNetOpenEnum 返回的资源句柄传递给 WNetEnumResource 函数。
通过调用 WNetCloseEnum 函数，在不再需要资源句柄时关闭资源句柄。

可以继续枚举 WNetEnumResource 检索的 NETRESOURCE 结构数组中所述的容器资源。如果 NETRESOURCE 结构的 dwUsage 成员等于 RESOURCEUSAGE_CONTAINER，请将结构的地址传递给 WNetOpenEnum 函数，以打开容器并继续枚举。如果 dwUsage 等于 RESOURCEUSAGE_CONNECTABLE，则应用程序可以将结构的地址传递给 WNetAddConnection2 函数或 WNetAddConnection3 函数以连接到资源。

首先，此示例调用 WNetOpenEnum 函数以开始枚举。该示例调用 GlobalAlloc 函数来分配所需的缓冲区，然后调用 ZeroMemory 函数将缓冲区内容设置为零。然后，该示例调用 WNetEnumResource 函数以继续枚举。每当 WNetEnumResource 检索到的 NETRESOURCE 结构的 dwUsage 成员等于 RESOURCEUSAGE_CONTAINER时，EnumerateFunc 函数以递归方式调用自身，并在调用 WNetOpenEnum 时使用指向该结构的指针。最后，示例调用 GlobalFree 函数以释放分配的内存，并调用 WNetCloseEnum 以结束枚举。

#ifndef UNICODE
#define UNICODE
#endif
#pragma comment(lib, "mpr.lib")

#include <windows.h>
#include <stdio.h>
#include <winnetwk.h>

BOOL WINAPI EnumerateFunc(LPNETRESOURCE lpnr);
void DisplayStruct(int i, LPNETRESOURCE lpnrLocal);

int main()
{

    LPNETRESOURCE lpnr = NULL;

    if (EnumerateFunc(lpnr) == FALSE) {
        printf("Call to EnumerateFunc failed\n");
        return 1;
    } else
        return 0;

}

BOOL WINAPI EnumerateFunc(LPNETRESOURCE lpnr)
{
    DWORD dwResult, dwResultEnum;
    HANDLE hEnum;
    DWORD cbBuffer = 16384;     // 16K is a good size
    DWORD cEntries = -1;        // enumerate all possible entries
    LPNETRESOURCE lpnrLocal;    // pointer to enumerated structures
    DWORD i;
    //
    // Call the WNetOpenEnum function to begin the enumeration.
    //
    dwResult = WNetOpenEnum(RESOURCE_GLOBALNET, // all network resources
                            RESOURCETYPE_ANY,   // all resources
                            0,  // enumerate all resources
                            lpnr,       // NULL first time the function is called
                            &hEnum);    // handle to the resource

    if (dwResult != NO_ERROR) {
        printf("WnetOpenEnum failed with error %d\n", dwResult);
        return FALSE;
    }
    //
    // Call the GlobalAlloc function to allocate resources.
    //
    lpnrLocal = (LPNETRESOURCE) GlobalAlloc(GPTR, cbBuffer);
    if (lpnrLocal == NULL) {
        printf("WnetOpenEnum failed with error %d\n", dwResult);
//      NetErrorHandler(hwnd, dwResult, (LPSTR)"WNetOpenEnum");
        return FALSE;
    }

    do {
        //
        // Initialize the buffer.
        //
        ZeroMemory(lpnrLocal, cbBuffer);
        //
        // Call the WNetEnumResource function to continue
        //  the enumeration.
        //
        dwResultEnum = WNetEnumResource(hEnum,  // resource handle
                                        &cEntries,      // defined locally as -1
                                        lpnrLocal,      // LPNETRESOURCE
                                        &cbBuffer);     // buffer size
        //
        // If the call succeeds, loop through the structures.
        //
        if (dwResultEnum == NO_ERROR) {
            for (i = 0; i < cEntries; i++) {
                // Call an application-defined function to
                //  display the contents of the NETRESOURCE structures.
                //
                DisplayStruct(i, &lpnrLocal[i]);

                // If the NETRESOURCE structure represents a container resource, 
                //  call the EnumerateFunc function recursively.

                if (RESOURCEUSAGE_CONTAINER == (lpnrLocal[i].dwUsage
                                                & RESOURCEUSAGE_CONTAINER))
//          if(!EnumerateFunc(hwnd, hdc, &lpnrLocal[i]))
                    if (!EnumerateFunc(&lpnrLocal[i]))
                        printf("EnumerateFunc returned FALSE\n");
//            TextOut(hdc, 10, 10, "EnumerateFunc returned FALSE.", 29);
            }
        }
        // Process errors.
        //
        else if (dwResultEnum != ERROR_NO_MORE_ITEMS) {
            printf("WNetEnumResource failed with error %d\n", dwResultEnum);

//      NetErrorHandler(hwnd, dwResultEnum, (LPSTR)"WNetEnumResource");
            break;
        }
    }
    //
    // End do.
    //
    while (dwResultEnum != ERROR_NO_MORE_ITEMS);
    //
    // Call the GlobalFree function to free the memory.
    //
    GlobalFree((HGLOBAL) lpnrLocal);
    //
    // Call WNetCloseEnum to end the enumeration.
    //
    dwResult = WNetCloseEnum(hEnum);

    if (dwResult != NO_ERROR) {
        //
        // Process errors.
        //
        printf("WNetCloseEnum failed with error %d\n", dwResult);
//    NetErrorHandler(hwnd, dwResult, (LPSTR)"WNetCloseEnum");
        return FALSE;
    }

    return TRUE;
}

void DisplayStruct(int i, LPNETRESOURCE lpnrLocal)
{
    printf("NETRESOURCE[%d] Scope: ", i);
    switch (lpnrLocal->dwScope) {
    case (RESOURCE_CONNECTED):
        printf("connected\n");
        break;
    case (RESOURCE_GLOBALNET):
        printf("all resources\n");
        break;
    case (RESOURCE_REMEMBERED):
        printf("remembered\n");
        break;
    default:
        printf("unknown scope %d\n", lpnrLocal->dwScope);
        break;
    }

    printf("NETRESOURCE[%d] Type: ", i);
    switch (lpnrLocal->dwType) {
    case (RESOURCETYPE_ANY):
        printf("any\n");
        break;
    case (RESOURCETYPE_DISK):
        printf("disk\n");
        break;
    case (RESOURCETYPE_PRINT):
        printf("print\n");
        break;
    default:
        printf("unknown type %d\n", lpnrLocal->dwType);
        break;
    }

    printf("NETRESOURCE[%d] DisplayType: ", i);
    switch (lpnrLocal->dwDisplayType) {
    case (RESOURCEDISPLAYTYPE_GENERIC):
        printf("generic\n");
        break;
    case (RESOURCEDISPLAYTYPE_DOMAIN):
        printf("domain\n");
        break;
    case (RESOURCEDISPLAYTYPE_SERVER):
        printf("server\n");
        break;
    case (RESOURCEDISPLAYTYPE_SHARE):
        printf("share\n");
        break;
    case (RESOURCEDISPLAYTYPE_FILE):
        printf("file\n");
        break;
    case (RESOURCEDISPLAYTYPE_GROUP):
        printf("group\n");
        break;
    case (RESOURCEDISPLAYTYPE_NETWORK):
        printf("network\n");
        break;
    default:
        printf("unknown display type %d\n", lpnrLocal->dwDisplayType);
        break;
    }

    printf("NETRESOURCE[%d] Usage: 0x%x = ", i, lpnrLocal->dwUsage);
    if (lpnrLocal->dwUsage & RESOURCEUSAGE_CONNECTABLE)
        printf("connectable ");
    if (lpnrLocal->dwUsage & RESOURCEUSAGE_CONTAINER)
        printf("container ");
    printf("\n");

    printf("NETRESOURCE[%d] Localname: %S\n", i, lpnrLocal->lpLocalName);
    printf("NETRESOURCE[%d] Remotename: %S\n", i, lpnrLocal->lpRemoteName);
    printf("NETRESOURCE[%d] Comment: %S\n", i, lpnrLocal->lpComment);
    printf("NETRESOURCE[%d] Provider: %S\n", i, lpnrLocal->lpProvider);
    printf("\n");
}

有关使用应用程序定义的错误处理程序的详细信息，请参阅检索网络错误。

枚举网络资源

反馈

反馈

其他资源