Creación de un proveedor de Automatización de la interfaz de usuario de Client-Side (proxy)

  • Artículo

Este tema contiene código de ejemplo que muestra cómo implementar un lado cliente, o proxy, proveedor de Microsoft Automatización de la interfaz de usuario.

Ejemplo 1: Enumeración de la tabla de generador de proxy

En el código de ejemplo siguiente se enumeran las entradas de la tabla de generador de proxy y se muestra el nombre de clase del control admitido. En el caso de los servidores proxy que no se proporcionan con el sistema operativo, se muestra el nombre de la imagen.

HRESULT GetProxyTable()
{
    IUIAutomationProxyFactoryMapping* pMap;
    IUIAutomationProxyFactoryEntry* pEntry;
    UINT count;
    BSTR className;
    BSTR imageName;

    HRESULT hr = g_pAutomation->get_ProxyFactoryMapping(&pMap);
    if (SUCCEEDED(hr))
    {
        if (SUCCEEDED(pMap->get_Count(&count)))
        {
            for (UINT x = 0; x < count; x++)
            {
                if (SUCCEEDED(pMap->GetEntry(x, &pEntry)))
                {
                    pEntry->get_ClassName(&className);
                    if (className)
                    {
                        std::wcout << className << L"\t";
                        SysFreeString(className);
                    }
                    if (SUCCEEDED(pEntry->get_ImageName(&imageName)))
                    {
                        if (imageName)
                        {
                            std::wcout << imageName;
                            SysFreeString(imageName);
                        }
                        std::wcout << L"\n";
                    }
                }
                pEntry->Release();
            }
        }
        pMap->Release();
    }

    return hr;
}

Ejemplo 2: Implementar un proxy simple para controles de botón

El código de ejemplo siguiente implementa un proxy simple para los controles que tienen el nombre de clase "Button" y agrega una entrada para el proxy a la tabla de generador de proxy. En este ejemplo se usa el cuadro de diálogo Fuente del Bloc de notas para mostrar el proxy.

// Registers a proxy for controls with the class name "BUTTON" and
// demonstrates it on the Font dialog of Notepad (which should be
// open when running this code).
#include "stdafx.h"
#include <stdio.h>
#include <tchar.h>

#include <windows.h>
#include <UIAutomation.h>

template <class T> void SafeRelease(T **ppT)
{
    if (*ppT)
    {
        (*ppT)->Release();
        *ppT = NULL;
    }
}

// A simple proxy for the proxy factory to create.
class ReallySimpleProxy : public IRawElementProviderSimple
{
public:
    ReallySimpleProxy(HWND hwnd):_refCount(1), _hWnd(hwnd) { }
    virtual ~ReallySimpleProxy() {}

    // IUnknown methods.
    IFACEMETHODIMP_(ULONG) AddRef() 
    { 
        return InterlockedIncrement(&_refCount);
    }
    IFACEMETHODIMP_(ULONG) Release()
    {
        long val = InterlockedDecrement(&_refCount);
        if(val == 0)
        {
            delete this;
        }
        return val;
    }

    IFACEMETHODIMP QueryInterface(REFIID riid, void** ppInterface)
    {
        if(riid == __uuidof(IUnknown))
            *ppInterface =(IUnknown*)((IRawElementProviderSimple*)this);
        else if(riid == __uuidof(IRawElementProviderSimple))
            *ppInterface =(IRawElementProviderSimple*)this;
        else
        {
            *ppInterface = NULL;
            return E_NOINTERFACE;
        }

        ((IUnknown*)(*ppInterface))->AddRef();
        return S_OK;
    }

    // IRawElementProviderSimple methods.
    IFACEMETHODIMP get_ProviderOptions(ProviderOptions * pRetVal)
    {
        *pRetVal = ProviderOptions_ClientSideProvider;
        return S_OK;
    }

    IFACEMETHODIMP GetPatternProvider(PATTERNID patternId, IUnknown ** pRetVal)
    {
        *pRetVal = NULL;
        return S_OK;
    }

    IFACEMETHODIMP GetPropertyValue(PROPERTYID propertyId, VARIANT * pRetVal)
    {
        pRetVal->vt = VT_EMPTY;

        // A String value to test
        if(propertyId == UIA_NamePropertyId)
        {
            pRetVal->vt = VT_BSTR;
            pRetVal->bstrVal = SysAllocString( L"ReallySimpleProxy Control" );
        }

        // Provider Id
        if(propertyId == UIA_ProviderDescriptionPropertyId)
        {
            pRetVal->vt = VT_BSTR;
            pRetVal->bstrVal = SysAllocString( L"Sample: ReallySimpleProxy" );
        }

        return S_OK;
    }

    IFACEMETHODIMP get_HostRawElementProvider(
        IRawElementProviderSimple ** pRetVal)
    {
        return UiaHostProviderFromHwnd(_hWnd, pRetVal); 
    }

private:
    ULONG _refCount;

    HWND _hWnd; // Window handle for this object.
};

// A simple proxy factory that creates a simple proxy.
class SimpleProxyFactory : public IUIAutomationProxyFactory
{
public:
    SimpleProxyFactory():_refCount(1) {}
    virtual ~SimpleProxyFactory() {}

    // IUnknown methods.
    IFACEMETHODIMP_(ULONG) AddRef() 
    { 
        return InterlockedIncrement(&_refCount);
    }
    IFACEMETHODIMP_(ULONG) Release()
    {
        long val = InterlockedDecrement(&_refCount);
        if(val == 0)
        {
            delete this;
        }
        return val;
    }

    IFACEMETHODIMP QueryInterface(REFIID riid, void** ppInterface)
    {
        if(riid == __uuidof(IUnknown))
            *ppInterface =(IUnknown*)((IUIAutomationProxyFactory*)this);
        else if(riid == __uuidof(IUIAutomationProxyFactory))
            *ppInterface =(IUIAutomationProxyFactory*)this;
        else
        {
            *ppInterface = NULL;
            return E_NOINTERFACE;
        }

        ((IUnknown*)(*ppInterface))->AddRef();
        return S_OK;
    }

    // IUIAutomationProxyFactory methods.
    IFACEMETHODIMP CreateProvider (UIA_HWND hwnd, LONG idObject, LONG idChild,
        IRawElementProviderSimple **ppRetVal )
    {
        *ppRetVal = new ReallySimpleProxy((HWND)hwnd);
        return S_OK;
    }

    IFACEMETHODIMP get_ProxyFactoryId ( BSTR *pRetVal )
    {
        *pRetVal = SysAllocString(L"Simple Proxy Factory");
        return S_OK;
    }

private:
    ULONG _refCount;
};


HRESULT CheckElement(IUIAutomation *uia, HWND hwnd)
{
    IUIAutomationElement * buttonEl = NULL;
    BSTR name = NULL;
    BSTR providerDescription = NULL;

    wprintf( L"Getting AutomationElement for the button...\n" );
    HRESULT hr = uia->ElementFromHandle(hwnd, &buttonEl);
    if (FAILED(hr))
        goto cleanup;
    if (buttonEl == NULL)
    {
        hr = E_FAIL;
        goto cleanup;
    }

    hr = buttonEl->get_CurrentName(&name);
    if (FAILED(hr))
        goto cleanup;

    hr = buttonEl->get_CurrentProviderDescription(&providerDescription);
    if (FAILED(hr))
        goto cleanup;

    wprintf( L"Got Element:\n  %s\n  %s\n\n", name, providerDescription);
cleanup:
    SysFreeString(providerDescription);
    SysFreeString(name);
    SafeRelease(&buttonEl);

    return hr;
}


int _tmain(int argc, _TCHAR* argv[])
{
    IUIAutomation * uia = NULL;
    IUIAutomationProxyFactoryMapping * proxyMapping = NULL;
    IUIAutomationProxyFactoryEntry * simpleEntry = NULL;
    IUIAutomationProxyFactory *simpleFactory = NULL;
    BSTR bstrClassName = NULL;

    wprintf( L"Initializing COM...\n" );
    HRESULT hr = CoInitializeEx( NULL, COINIT_APARTMENTTHREADED );
    if (FAILED(hr))
        goto cleanup;

    wprintf( L"CoCreating Automation Object...\n" );
    hr = CoCreateInstance(__uuidof(CUIAutomation), NULL, CLSCTX_INPROC_SERVER,
        __uuidof(IUIAutomation), (void **)&uia);
    if (FAILED(hr))
        goto cleanup;


    wprintf( L"Finding Notepad Font Window...\n" );
    HWND fontHwnd = FindWindow(NULL,L"Font");
    if (fontHwnd == NULL)
        goto cleanup;

    wprintf( L"Finding the OK button in Font Window...\n" );
    HWND buttonHwnd = FindWindowEx(fontHwnd, NULL, L"BUTTON", L"OK");
    if (buttonHwnd == NULL)
        goto cleanup;

    wprintf( L"Checking Name and Provider Description without our Proxy:\n" );
    CheckElement(uia, buttonHwnd);

    wprintf( L"Getting the Proxy Factory Mapping Object...\n" );
    hr = uia->get_ProxyFactoryMapping(&proxyMapping);
    if (FAILED(hr))
        goto cleanup;
    if (proxyMapping == NULL)
        goto cleanup;

    wprintf( L"Creating the Proxy Factory...\n" );
    simpleFactory = new SimpleProxyFactory();
    if (simpleFactory == NULL)
        goto cleanup;

    wprintf( L"Creating the Proxy Factory Entry...\n" );
    hr = uia->CreateProxyFactoryEntry(simpleFactory, &simpleEntry);
    if (FAILED(hr))
        goto cleanup;
   bstrClassName = SysAllocString(L"BUTTON");
    if (bstrClassName == NULL)
        goto cleanup;

    // Match HWNDs with Button class name.
    hr = simpleEntry->put_ClassName(bstrClassName);   
    if (FAILED(hr))
        goto cleanup;

    // Match any process ImageName.
    hr = simpleEntry->put_ImageName(NULL);            
    if (FAILED(hr))
        goto cleanup;

    // Do not allow substring matching.
    hr = simpleEntry->put_AllowSubstringMatch(FALSE); 
    if (FAILED(hr))
        goto cleanup;

    // Enter it into the mapping.
    hr = proxyMapping->InsertEntry(0, simpleEntry);
    if (FAILED(hr))
        goto cleanup;

    wprintf( L"Checking Name and Provider Description with our Proxy:\n" );
    CheckElement(uia, buttonHwnd);

cleanup:

    SafeRelease(&simpleEntry);
    SafeRelease(&simpleFactory);
    SafeRelease(&proxyMapping);
    SafeRelease(&uia);
    SysFreeString(bstrClassName);
    CoUninitialize();

    return 0;
}

Conceptual

Implementación de un proveedor de Client-Side Automatización de la interfaz de usuario

Temas de procedimientos para proveedores de Automatización de la interfaz de usuario