读取 attributeSchema 和 classSchema 对象

本主题提供了直接从架构容器中的 attributeSchemaclassSchema 对象读取数据的代码示例和指南。 请注意,在大多数编程情况下,当必须读取有关类或属性定义的数据时,从抽象架构中读取数据会更有效,如读取抽象架构中所述。

用于读取架构容器的接口和技术与用于读取 Active Directory 域服务中任何对象的接口和技术相同。 准则包括:

  • 要绑定到架构容器,可通过绑定到 rootDSE 并读取 schemaNamingContext 属性来获取其可分辨名称,如服务器绑定和 RootDSE 中所述。
  • 使用架构容器的 IADsContainer 指针来枚举 attributeSchemaclassSchema 对象。
  • 使用 IADsIDirectoryObject 接口来检索 attributeSchemaclassSchema 对象的属性。
  • 使用 ADsOpenObjectADsGetObject 函数直接绑定到 attributeSchemaclassSchema 对象。
  • 如果要读取多个 attributeSchemaclassSchema 对象,可以绑定到架构容器上的 IADsContainer 指针,并使用 IADsContainer.GetObject 方法绑定到各个类和属性对象,从而提高性能。 这比重复调用 ADsOpenObjectADsGetObject 来绑定各个类和属性对象更为有效。 使用 cn 属性为 IADsContainer.GetObject 调用建立相对路径(例如,“cn=user”表示用户类的 classSchema 对象)。
  • 使用架构容器的 IDirectorySearch 指针来查询架构中与搜索筛选器匹配的属性或类。

有关演示搜索架构对象的不同方法的代码示例,请参阅搜索架构对象的示例代码

以下 C++ 代码示例绑定到架构容器上的 IADsContainer 指针,然后使用 ADsBuildEnumeratorADsEnumerateNext 函数来枚举其内容。 请注意,该枚举包括所有 attributeSchemaclassSchema 对象,以及单个 subSchema 对象,即抽象架构。

对于每个枚举对象,代码示例使用 IADs.Class 属性来确定它是 attributeSchema 还是 classSchema 对象。 代码示例展示了如何从抽象架构中读取不可用的属性。

//  Add activeds.lib to the project.
//  Add adsiid.lib to the project.

#include "stdafx.h"
#include <windows.h>
#include <stdio.h>
#include <ole2.h>
#include <activeds.h>
#include <atlbase.h>

//  Forward declarations.
void ProcessAttribute(IADs *pChild);
void ProcessClass(IADs *pChild);

//  Entry point for the application.
int wmain(int argc, WCHAR* argv[])
{
    HRESULT hr;

    hr = CoInitialize(NULL);
    if(SUCCEEDED(hr))
    {
        CComBSTR sbstrDSPath;
        CComVariant svar;
        IADs *pRootDSE = NULL;
        IADsContainer *pSchema = NULL;  
        IEnumVARIANT *pEnum = NULL;
        ULONG lFetch;
        CComBSTR sbstrClass; 
        DWORD dwClasses = 0, dwAttributes = 0, dwUnknownClass = 0;

        //  Bind to rootDSE to get the schemaNamingContext property.
        hr = ADsGetObject(L"LDAP://rootDSE", IID_IADs, (void**)&pRootDSE);
        if (FAILED(hr)) 
        {
            wprintf(L"ADsGetObject failed: 0x%x\n", hr);
            goto cleanup;
        }

        hr = pRootDSE->Get(CComBSTR("schemaNamingContext"), &svar);
        sbstrDSPath = "LDAP://";
        sbstrDSPath += svar.bstrVal;

        //  Bind to the actual schema container.
        wprintf(L"Binding to %s\n", sbstrDSPath);
        hr = ADsGetObject(sbstrDSPath, IID_IADsContainer, (void**) &pSchema);
        if (FAILED(hr)) 
        {
            wprintf(L"ADsGetObject to schema failed: 0x%x\n", hr);
            goto cleanup;
        }

        //  Enumerate the attribute and class objects in the schema container.
        hr = ADsBuildEnumerator(pSchema, &pEnum);
        if (FAILED(hr)) 
        {
            wprintf(L"ADsBuildEnumerator failed: 0x%x\n", hr);
            goto cleanup;
        }

        hr = ADsEnumerateNext(pEnum, 1, &svar, &lFetch);
        while(S_OK == hr && 1 == lFetch)
        {
            IADs *pChild = NULL;

            //  Get an IADs pointer on the child object.
            hr = V_DISPATCH(&svar)->QueryInterface(IID_IADs, (void**) &pChild);
            if (SUCCEEDED(hr)) 
            {
                //  Verify that this is a class, attribute, or subSchema object.
                hr = pChild->get_Class(&sbstrClass);
                if (SUCCEEDED(hr)) 
                {
                    //  Get data. This depends on type of schema element.
                    if (_wcsicmp(L"classSchema", sbstrClass) == 0)
                    {
                        dwClasses++;
                        wprintf(L"%s\n", sbstrClass);
                        ProcessClass(pChild);
                        wprintf(L"\n");
                    }
                    else if (_wcsicmp(L"attributeSchema", sbstrClass) == 0)
                    {
                        dwAttributes++;
                        wprintf(L"%s\n", sbstrClass);
                        ProcessAttribute(pChild);
                        wprintf(L"\n");
                    }
                    else if (_wcsicmp(L"subSchema", sbstrClass) == 0) 
                    {
                        wprintf(L"abstract schema");
                        wprintf(L"\n");
                    }
                    else
                    {
                        dwUnknownClass++;
                    }
                }

                pChild->Release();
            }

            hr = ADsEnumerateNext(pEnum, 1, &svar, &lFetch);
        }

        wprintf(L"Classes: %u\nAttributes: %u\nUnknown: %u\n", dwClasses, dwAttributes, dwUnknownClass);

cleanup:
        if (pRootDSE)
        {
            pRootDSE->Release();
        }

        if (pEnum)
        {
            ADsFreeEnumerator(pEnum);
        }

        if (pSchema)
        {
            pSchema->Release();
        }

    }    

    CoUninitialize();

    return 0;
}


//  PrintGUIDFromVariant
//  Prints a GUID in string format.
void PrintGUIDFromVariant(VARIANT varGUID)
{
    HRESULT hr;
    void HUGEP *pArray;
    WCHAR szGUID[40];
    LPGUID pGUID;

    DWORD dwLen = sizeof(GUID);

    hr = SafeArrayAccessData(V_ARRAY(&varGUID), &pArray);
    if(SUCCEEDED(hr))
    {
        pGUID = (LPGUID)pArray;

        //  Convert GUID to string.
        StringFromGUID2(*pGUID, szGUID, 40); 

        //  Print GUID.
        wprintf(L",%s",szGUID);

        SafeArrayUnaccessData(V_ARRAY(&varGUID));
    }
}


// PrintADSPropertyValue
void PrintADSPropertyValue(VARIANT var, BSTR bstrPropName, HRESULT hr) 
{
    if (E_ADS_PROPERTY_NOT_FOUND == hr)
    {
        wprintf(L"-- not set --\n");
    }
    else if (FAILED(hr))
    {
        wprintf(L"get %s failed: 0x%x\n", bstrPropName, hr);
    }
    else 
    {
        switch (var.vt) 
        {
        case VT_BSTR:
            wprintf(L"%s\n", var.bstrVal);
            break;

        case VT_I4:
            wprintf(L"%u\n", var.iVal);
            break;

        case VT_BOOL:
            wprintf(L"%s\n", var.boolVal ? L"TRUE" : L"FALSE");
            break;

        default:
            wprintf(L"-- ??? --\n");
        }
    }
}

//  ProcessAttribute
//  Gets information about an attributeClass object.
void ProcessAttribute(IADs *pChild)
{
    HRESULT hr;
    CComVariant svar;
    CComBSTR sbstrPropName;

    //  Get the attribute Common-Name (cn) property. 
    sbstrPropName = "cn";
    hr = pChild->Get(sbstrPropName, &svar);
    PrintADSPropertyValue(svar, sbstrPropName, hr);

    //  Get the attribute lDAPDisplayName.
    sbstrPropName = "lDAPDisplayName";
    hr = pChild->Get(sbstrPropName, &svar);
    PrintADSPropertyValue(svar, sbstrPropName, hr);

    //  Get the class linkID. 
    sbstrPropName = "linkID";
    hr = pChild->Get(sbstrPropName, &svar);
    PrintADSPropertyValue(svar, sbstrPropName, hr);

    //  Get the attribute schemaIDGUID. 
    sbstrPropName = "schemaIDGUID";
    hr = pChild->Get(sbstrPropName, &svar);
    if (E_ADS_PROPERTY_NOT_FOUND == hr)
    {
        wprintf(L"-- not set --\n");
    }
    else if(SUCCEEDED(hr))
    {
        PrintGUIDFromVariant(svar);
    }

    //  Get the attribute attributeSecurityGUID. 
    sbstrPropName = "attributeSecurityGUID";
    hr = pChild->Get(sbstrPropName, &svar);
    if (E_ADS_PROPERTY_NOT_FOUND == hr)
    {
        wprintf(L"-- not set --\n");
    }
    else if (SUCCEEDED(hr))
    {
        PrintGUIDFromVariant(svar);
    }

    //  Get the attribute attributeSyntax property. 
    sbstrPropName = "attributeSyntax";
    hr = pChild->Get(sbstrPropName, &svar);
    PrintADSPropertyValue(svar, sbstrPropName, hr);

    //  Get the attribute's oMSyntax property. 
    sbstrPropName = "oMSyntax";
    hr = pChild->Get(sbstrPropName, &svar);
    PrintADSPropertyValue(svar, sbstrPropName, hr);
}


//  ProcessClass
//  Gets information about a schema class.
void ProcessClass(IADs *pChild)
{
    HRESULT hr;
    CComVariant svar;
    CComBSTR sbstrPropName;

    //  Get the class cn.
    sbstrPropName = "cn";
    hr = pChild->Get(sbstrPropName, &svar);
    PrintADSPropertyValue(svar, sbstrPropName, hr);

    //  Get the class lDAPDisplayName.
    sbstrPropName = "lDAPDisplayName";
    hr = pChild->Get(sbstrPropName, &svar);
    PrintADSPropertyValue(svar, sbstrPropName, hr);

    //  Get the class schemaIDGUID. 
    sbstrPropName = "schemaIDGUID";
    hr = pChild->Get(sbstrPropName, &svar);
    if (FAILED(hr))
    {
        wprintf(L",get schemaIDGUID failed: 0x%x", hr);
    }
    else 
    {
        PrintGUIDFromVariant(svar);
    }

    //  Get the class adminDescription property. 
    sbstrPropName = "adminDescription";
    hr = pChild->Get(sbstrPropName, &svar);
    PrintADSPropertyValue(svar, sbstrPropName, hr);

    //  Get the class adminDisplayName property. 
    sbstrPropName = "adminDisplayName";
    hr = pChild->Get(sbstrPropName, &svar);
    PrintADSPropertyValue(svar, sbstrPropName, hr);

    //  Get the class rDNAttID. 
    sbstrPropName = "rDNAttID";
    hr = pChild->Get(sbstrPropName, &svar);
    PrintADSPropertyValue(svar, sbstrPropName, hr);

    //  Get the class defaultHidingValue. 
    sbstrPropName = "defaultHidingValue";
    hr = pChild->Get(sbstrPropName, &svar);
    PrintADSPropertyValue(svar, sbstrPropName, hr);

    //  Get the class defaultObjectCategory. 
    sbstrPropName = "defaultObjectCategory";
    hr = pChild->Get(sbstrPropName, &svar);
    PrintADSPropertyValue(svar, sbstrPropName, hr);

    //  Get the class systemOnly value.
    sbstrPropName = "systemOnly";
    hr = pChild->Get(sbstrPropName, &svar);
    PrintADSPropertyValue(svar, sbstrPropName, hr);

    //  Get the class defaultSecurityDescriptor.
    sbstrPropName = "defaultSecurityDescriptor";
    hr = pChild->Get(sbstrPropName, &svar);
    PrintADSPropertyValue(svar, sbstrPropName, hr);
}