C++开发BHO之HelloWorld



原文：

http://msdn.microsoft.com/en-us/library/bb250489(v=vs.85).aspx

开发工具VS2010。

步骤如图：

生成的HelloWorldBHO.h的代码如下：

// HelloWorldBHO.h : CHelloWorldBHO 的声明

#pragma once
#include "resource.h"       // 主符号



#include "HelloWorld_i.h"



#if defined(_WIN32_WCE) && !defined(_CE_DCOM) && !defined(_CE_ALLOW_SINGLE_THREADED_OBJECTS_IN_MTA)
#error "Windows CE 平台(如不提供完全 DCOM 支持的 Windows Mobile 平台)上无法正确支持单线程 COM 对象。定义 _CE_ALLOW_SINGLE_THREADED_OBJECTS_IN_MTA 可强制 ATL 支持创建单线程 COM 对象实现并允许使用其单线程 COM 对象实现。rgs 文件中的线程模型已被设置为“Free”，原因是该模型是非 DCOM Windows CE 平台支持的唯一线程模型。"
#endif

using namespace ATL;


// CHelloWorldBHO

class ATL_NO_VTABLE CHelloWorldBHO :
    public CComObjectRootEx,
    public CComCoClass,
    public IObjectWithSiteImpl,
    public IDispatchImpl/*wMajor =*/ 1, /*wMinor =*/ 0>
{
public:
    CHelloWorldBHO()
    {
    }

DECLARE_REGISTRY_RESOURCEID(IDR_HELLOWORLDBHO)

DECLARE_NOT_AGGREGATABLE(CHelloWorldBHO)

BEGIN_COM_MAP(CHelloWorldBHO)
    COM_INTERFACE_ENTRY(IHelloWorldBHO)
    COM_INTERFACE_ENTRY(IDispatch)
    COM_INTERFACE_ENTRY(IObjectWithSite)
END_COM_MAP()



    DECLARE_PROTECT_FINAL_CONSTRUCT()

    HRESULT FinalConstruct()
    {
        return S_OK;
    }

    void FinalRelease()
    {
    }

public:



};

OBJECT_ENTRY_AUTO(__uuidof(HelloWorldBHO), CHelloWorldBHO)

// HelloWorldBHO.h : CHelloWorldBHO 的声明

#pragma once
#include "resource.h"       // 主符号



#include "HelloWorld_i.h"



#if defined(_WIN32_WCE) && !defined(_CE_DCOM) && !defined(_CE_ALLOW_SINGLE_THREADED_OBJECTS_IN_MTA)
#error "Windows CE 平台(如不提供完全 DCOM 支持的 Windows Mobile 平台)上无法正确支持单线程 COM 对象。定义 _CE_ALLOW_SINGLE_THREADED_OBJECTS_IN_MTA 可强制 ATL 支持创建单线程 COM 对象实现并允许使用其单线程 COM 对象实现。rgs 文件中的线程模型已被设置为“Free”，原因是该模型是非 DCOM Windows CE 平台支持的唯一线程模型。"
#endif

using namespace ATL;


// CHelloWorldBHO

class ATL_NO_VTABLE CHelloWorldBHO :
	public CComObjectRootEx,
	public CComCoClass,
	public IObjectWithSiteImpl,
	public IDispatchImpl
{
public:
	CHelloWorldBHO()
	{
	}

DECLARE_REGISTRY_RESOURCEID(IDR_HELLOWORLDBHO)

DECLARE_NOT_AGGREGATABLE(CHelloWorldBHO)

BEGIN_COM_MAP(CHelloWorldBHO)
	COM_INTERFACE_ENTRY(IHelloWorldBHO)
	COM_INTERFACE_ENTRY(IDispatch)
	COM_INTERFACE_ENTRY(IObjectWithSite)
END_COM_MAP()



	DECLARE_PROTECT_FINAL_CONSTRUCT()

	HRESULT FinalConstruct()
	{
		return S_OK;
	}

	void FinalRelease()
	{
	}

public:



};

OBJECT_ENTRY_AUTO(__uuidof(HelloWorldBHO), CHelloWorldBHO)

HelloWorldBHO.cpp的代码如下：

// HelloWorldBHO.cpp : CHelloWorldBHO 的实现

#include "stdafx.h"
#include "HelloWorldBHO.h"


// CHelloWorldBHO

// HelloWorldBHO.cpp : CHelloWorldBHO 的实现

#include "stdafx.h"
#include "HelloWorldBHO.h"


// CHelloWorldBHO

HelloWorld.cpp的代码如下：

// HelloWorld.cpp : DLL 导出的实现。


#include "stdafx.h"
#include "resource.h"
#include "HelloWorld_i.h"
#include "dllmain.h"


// 用于确定 DLL 是否可由 OLE 卸载。
STDAPI DllCanUnloadNow(void)
{
            return _AtlModule.DllCanUnloadNow();
    }

// 返回一个类工厂以创建所请求类型的对象。
STDAPI DllGetClassObject(REFCLSID rclsid, REFIID riid, LPVOID* ppv)
{
        return _AtlModule.DllGetClassObject(rclsid, riid, ppv);
}

// DllRegisterServer - 在系统注册表中添加项。
STDAPI DllRegisterServer(void)
{
    // 注册对象、类型库和类型库中的所有接口
    HRESULT hr = _AtlModule.DllRegisterServer();
        return hr;
}

// DllUnregisterServer - 在系统注册表中移除项。
STDAPI DllUnregisterServer(void)
{
    HRESULT hr = _AtlModule.DllUnregisterServer();
        return hr;
}

// DllInstall - 按用户和计算机在系统注册表中逐一添加/移除项。
STDAPI DllInstall(BOOL bInstall, LPCWSTR pszCmdLine)
{
    HRESULT hr = E_FAIL;
    static const wchar_t szUserSwitch[] = L"user";

    if (pszCmdLine != NULL)
    {
        if (_wcsnicmp(pszCmdLine, szUserSwitch, _countof(szUserSwitch)) == 0)
        {
            ATL::AtlSetPerUserRegistration(true);
        }
    }

    if (bInstall)
    {
        hr = DllRegisterServer();
        if (FAILED(hr))
        {
            DllUnregisterServer();
        }
    }
    else
    {
        hr = DllUnregisterServer();
    }

    return hr;
}

// HelloWorld.cpp : DLL 导出的实现。


#include "stdafx.h"
#include "resource.h"
#include "HelloWorld_i.h"
#include "dllmain.h"


// 用于确定 DLL 是否可由 OLE 卸载。
STDAPI DllCanUnloadNow(void)
{
			return _AtlModule.DllCanUnloadNow();
	}

// 返回一个类工厂以创建所请求类型的对象。
STDAPI DllGetClassObject(REFCLSID rclsid, REFIID riid, LPVOID* ppv)
{
		return _AtlModule.DllGetClassObject(rclsid, riid, ppv);
}

// DllRegisterServer - 在系统注册表中添加项。
STDAPI DllRegisterServer(void)
{
	// 注册对象、类型库和类型库中的所有接口
	HRESULT hr = _AtlModule.DllRegisterServer();
		return hr;
}

// DllUnregisterServer - 在系统注册表中移除项。
STDAPI DllUnregisterServer(void)
{
	HRESULT hr = _AtlModule.DllUnregisterServer();
		return hr;
}

// DllInstall - 按用户和计算机在系统注册表中逐一添加/移除项。
STDAPI DllInstall(BOOL bInstall, LPCWSTR pszCmdLine)
{
	HRESULT hr = E_FAIL;
	static const wchar_t szUserSwitch[] = L"user";

	if (pszCmdLine != NULL)
	{
		if (_wcsnicmp(pszCmdLine, szUserSwitch, _countof(szUserSwitch)) == 0)
		{
			ATL::AtlSetPerUserRegistration(true);
		}
	}

	if (bInstall)
	{	
		hr = DllRegisterServer();
		if (FAILED(hr))
		{
			DllUnregisterServer();
		}
	}
	else
	{
		hr = DllUnregisterServer();
	}

	return hr;
}

dllmain.cpp的代码如下：

// dllmain.cpp : DllMain 的实现。

#include "stdafx.h"
#include "resource.h"
#include "HelloWorld_i.h"
#include "dllmain.h"

CHelloWorldModule _AtlModule;

// DLL 入口点
extern "C" BOOL WINAPI DllMain(HINSTANCE hInstance, DWORD dwReason, LPVOID lpReserved)
{
    hInstance;
    return _AtlModule.DllMain(dwReason, lpReserved);
}

// dllmain.cpp : DllMain 的实现。

#include "stdafx.h"
#include "resource.h"
#include "HelloWorld_i.h"
#include "dllmain.h"

CHelloWorldModule _AtlModule;

// DLL 入口点
extern "C" BOOL WINAPI DllMain(HINSTANCE hInstance, DWORD dwReason, LPVOID lpReserved)
{
	hInstance;
	return _AtlModule.DllMain(dwReason, lpReserved); 
}

HelloWorld.rgs的内容如下：

HKCR
{
}

HKCR
{
}

HelloWorldBHO.rgs的内容如下：

HKCR
{
    NoRemove CLSID
    {
        ForceRemove {22024CC8-9043-49C7-AC80-A803A2912BF6} = s 'HelloWorldBHO Class'
        {
            ForceRemove Programmable
            InprocServer32 = s '%MODULE%'
            {
                val ThreadingModel = s 'Apartment'
            }
            TypeLib = s '{D05D8B0F-8126-4FE2-BC3D-D5A5248E7025}'
            Version = s '1.0'
        }
    }
}

HKCR
{
	NoRemove CLSID
	{
		ForceRemove {22024CC8-9043-49C7-AC80-A803A2912BF6} = s 'HelloWorldBHO Class'
		{
			ForceRemove Programmable
			InprocServer32 = s '%MODULE%'
			{
				val ThreadingModel = s 'Apartment'
			}
			TypeLib = s '{D05D8B0F-8126-4FE2-BC3D-D5A5248E7025}'
			Version = s '1.0'
		}
	}
}

HelloWorld.idl的内容：

// HelloWorld.idl : HelloWorld 的 IDL 源
//

// 此文件将由 MIDL 工具处理以
// 产生类型库(HelloWorld.tlb)和封送处理代码。

import "oaidl.idl";
import "ocidl.idl";

[
    object,
    uuid(9C44C518-EEBE-4126-B368-5B901F840255),
    dual,
    nonextensible,
    pointer_default(unique)
]
interface IHelloWorldBHO : IDispatch{
};
[
    uuid(D05D8B0F-8126-4FE2-BC3D-D5A5248E7025),
    version(1.0),
]
library HelloWorldLib
{
    importlib("stdole2.tlb");
    [
        uuid(22024CC8-9043-49C7-AC80-A803A2912BF6)
    ]
    coclass HelloWorldBHO
    {
        [default] interface IHelloWorldBHO;
    };
};

// HelloWorld.idl : HelloWorld 的 IDL 源
//

// 此文件将由 MIDL 工具处理以
// 产生类型库(HelloWorld.tlb)和封送处理代码。

import "oaidl.idl";
import "ocidl.idl";

[
	object,
	uuid(9C44C518-EEBE-4126-B368-5B901F840255),
	dual,
	nonextensible,
	pointer_default(unique)
]
interface IHelloWorldBHO : IDispatch{
};
[
	uuid(D05D8B0F-8126-4FE2-BC3D-D5A5248E7025),
	version(1.0),
]
library HelloWorldLib
{
	importlib("stdole2.tlb");
	[
		uuid(22024CC8-9043-49C7-AC80-A803A2912BF6)		
	]
	coclass HelloWorldBHO
	{
		[default] interface IHelloWorldBHO;
	};
};

HelloWorld.idl中的CLSID是22024CC8-9043-49C7-AC80-A803A2912BF6

其他的文件，暂时不重要。

修改HelloWorldBHO.h：

1、增加头文件

#include
#include

#include 
#include 

2、增加一个公有的SetSite方法：

public:

    STDMETHOD(SetSite)(IUnknown *pUnkSite);

public:

	STDMETHOD(SetSite)(IUnknown *pUnkSite);

3、增加私有的成员变量：

private:

    CComPtr  m_spWebBrowser;
    BOOL m_fAdvised;

private:

    CComPtr  m_spWebBrowser;
	BOOL m_fAdvised;

4、多继承一个类：

public IDispEventImpl<1, CHelloWorldBHO, &DIID_DWebBrowserEvents2, &LIBID_SHDocVw, 1, 1>

public IDispEventImpl<1, CHelloWorldBHO, &DIID_DWebBrowserEvents2, &LIBID_SHDocVw, 1, 1>

5、增加公有的方法OnDocumentComplete：

BEGIN_SINK_MAP(CHelloWorldBHO)
    SINK_ENTRY_EX(1, DIID_DWebBrowserEvents2, DISPID_DOCUMENTCOMPLETE, OnDocumentComplete)
END_SINK_MAP()

    // DWebBrowserEvents2
    void STDMETHODCALLTYPE OnDocumentComplete(IDispatch *pDisp, VARIANT *pvarURL);

BEGIN_SINK_MAP(CHelloWorldBHO)
    SINK_ENTRY_EX(1, DIID_DWebBrowserEvents2, DISPID_DOCUMENTCOMPLETE, OnDocumentComplete)
END_SINK_MAP()

    // DWebBrowserEvents2
    void STDMETHODCALLTYPE OnDocumentComplete(IDispatch *pDisp, VARIANT *pvarURL);

修改HelloWorldBHO.cpp，实现那两个方法：

STDMETHODIMP CHelloWorldBHO::SetSite(IUnknown* pUnkSite)
{
    if (pUnkSite != NULL)
    {
        // Cache the pointer to IWebBrowser2.
        HRESULT hr = pUnkSite->QueryInterface(IID_IWebBrowser2, (void **)&m_spWebBrowser);
        if (SUCCEEDED(hr))
        {
            // Register to sink events from DWebBrowserEvents2.
            hr = DispEventAdvise(m_spWebBrowser);
            if (SUCCEEDED(hr))
            {
                m_fAdvised = TRUE;
            }
        }
    }
    else
    {
        // Unregister event sink.
        if (m_fAdvised)
        {
            DispEventUnadvise(m_spWebBrowser);
            m_fAdvised = FALSE;
        }

        // Release cached pointers and other resources here.
        m_spWebBrowser.Release();
    }

    // Call base class implementation.
    return IObjectWithSiteImpl::SetSite(pUnkSite);
}

void STDMETHODCALLTYPE CHelloWorldBHO::OnDocumentComplete(IDispatch *pDisp, VARIANT *pvarURL)
{
    // Retrieve the top-level window from the site.
    HWND hwnd;
    HRESULT hr = m_spWebBrowser->get_HWND((LONG_PTR*)&hwnd);
    if (SUCCEEDED(hr))
    {
        // Output a message box when page is loaded.
        MessageBox(hwnd, L"Hello World!", L"BHO", MB_OK);
    }
}

STDMETHODIMP CHelloWorldBHO::SetSite(IUnknown* pUnkSite)
{
    if (pUnkSite != NULL)
    {
        // Cache the pointer to IWebBrowser2.
        HRESULT hr = pUnkSite->QueryInterface(IID_IWebBrowser2, (void **)&m_spWebBrowser);
        if (SUCCEEDED(hr))
        {
            // Register to sink events from DWebBrowserEvents2.
            hr = DispEventAdvise(m_spWebBrowser);
            if (SUCCEEDED(hr))
            {
                m_fAdvised = TRUE;
            }
        }
    }
    else
    {
        // Unregister event sink.
        if (m_fAdvised)
        {
            DispEventUnadvise(m_spWebBrowser);
            m_fAdvised = FALSE;
        }

        // Release cached pointers and other resources here.
        m_spWebBrowser.Release();
    }

    // Call base class implementation.
    return IObjectWithSiteImpl::SetSite(pUnkSite);
}

void STDMETHODCALLTYPE CHelloWorldBHO::OnDocumentComplete(IDispatch *pDisp, VARIANT *pvarURL)
{
    // Retrieve the top-level window from the site.
    HWND hwnd;
    HRESULT hr = m_spWebBrowser->get_HWND((LONG_PTR*)&hwnd);
    if (SUCCEEDED(hr))
    {
        // Output a message box when page is loaded.
        MessageBox(hwnd, L"Hello World!", L"BHO", MB_OK);
    }
}

dllmain.cpp的DllMain修改成：

extern "C" BOOL WINAPI DllMain(HINSTANCE hInstance, DWORD dwReason, LPVOID lpReserved)
{
    if (dwReason == DLL_PROCESS_ATTACH)
    {
        DisableThreadLibraryCalls(hInstance);
    }
    return _AtlModule.DllMain(dwReason, lpReserved);
}

extern "C" BOOL WINAPI DllMain(HINSTANCE hInstance, DWORD dwReason, LPVOID lpReserved)
{
    if (dwReason == DLL_PROCESS_ATTACH)
    {
        DisableThreadLibraryCalls(hInstance);
    }
    return _AtlModule.DllMain(dwReason, lpReserved); 
}

修改HelloWorld.rgs：

修改成：

HKLM {
  NoRemove SOFTWARE {
    NoRemove Microsoft {
      NoRemove Windows {
        NoRemove CurrentVersion {
          NoRemove Explorer {
            NoRemove 'Browser Helper Objects' {
              ForceRemove '{D2F7E1E3-C9DC-4349-B72C-D5A708D6DD77}' = s 'HelloWorldBHO' {
                val 'NoExplorer' = d '1'
              }
            }
          }
        }
      }
    }
  }
}

HKLM {
  NoRemove SOFTWARE {
    NoRemove Microsoft {   
      NoRemove Windows {
        NoRemove CurrentVersion {
          NoRemove Explorer {
            NoRemove 'Browser Helper Objects' {
              ForceRemove '{D2F7E1E3-C9DC-4349-B72C-D5A708D6DD77}' = s 'HelloWorldBHO' {
                val 'NoExplorer' = d '1'
              }
            }
          }
        }
      }
    }
  }
}

其中的{D2F7E1E3-C9DC-4349-B72C-D5A708D6DD77}，需要改成HelloWorld.idl中的CLSID，当前文件的CLSID是

{22024CC8-9043-49C7-AC80-A803A2912BF6}

修改完后：

HelloWorldBHO.h：

// HelloWorldBHO.h : CHelloWorldBHO 的声明

#pragma once
#include "resource.h"       // 主符号

#include
#include

#include "HelloWorld_i.h"



#if defined(_WIN32_WCE) && !defined(_CE_DCOM) && !defined(_CE_ALLOW_SINGLE_THREADED_OBJECTS_IN_MTA)
#error "Windows CE 平台(如不提供完全 DCOM 支持的 Windows Mobile 平台)上无法正确支持单线程 COM 对象。定义 _CE_ALLOW_SINGLE_THREADED_OBJECTS_IN_MTA 可强制 ATL 支持创建单线程 COM 对象实现并允许使用其单线程 COM 对象实现。rgs 文件中的线程模型已被设置为“Free”，原因是该模型是非 DCOM Windows CE 平台支持的唯一线程模型。"
#endif

using namespace ATL;


// CHelloWorldBHO

class ATL_NO_VTABLE CHelloWorldBHO :
    public CComObjectRootEx,
    public CComCoClass,
    public IObjectWithSiteImpl,
    public IDispatchImpl/*wMajor =*/ 1, /*wMinor =*/ 0>,
    public IDispEventImpl<1, CHelloWorldBHO, &DIID_DWebBrowserEvents2, &LIBID_SHDocVw, 1, 1>
{
public:
    CHelloWorldBHO()
    {
    }

DECLARE_REGISTRY_RESOURCEID(IDR_HELLOWORLDBHO)

DECLARE_NOT_AGGREGATABLE(CHelloWorldBHO)

BEGIN_COM_MAP(CHelloWorldBHO)
    COM_INTERFACE_ENTRY(IHelloWorldBHO)
    COM_INTERFACE_ENTRY(IDispatch)
    COM_INTERFACE_ENTRY(IObjectWithSite)
END_COM_MAP()



    DECLARE_PROTECT_FINAL_CONSTRUCT()

    HRESULT FinalConstruct()
    {
        return S_OK;
    }

    void FinalRelease()
    {
    }

public:

    STDMETHOD(SetSite)(IUnknown *pUnkSite);

BEGIN_SINK_MAP(CHelloWorldBHO)
    SINK_ENTRY_EX(1, DIID_DWebBrowserEvents2, DISPID_DOCUMENTCOMPLETE, OnDocumentComplete)
END_SINK_MAP()

    // DWebBrowserEvents2
    void STDMETHODCALLTYPE OnDocumentComplete(IDispatch *pDisp, VARIANT *pvarURL);

private:

    CComPtr  m_spWebBrowser;
    BOOL m_fAdvised;
};

OBJECT_ENTRY_AUTO(__uuidof(HelloWorldBHO), CHelloWorldBHO)

// HelloWorldBHO.h : CHelloWorldBHO 的声明

#pragma once
#include "resource.h"       // 主符号

#include 
#include 

#include "HelloWorld_i.h"



#if defined(_WIN32_WCE) && !defined(_CE_DCOM) && !defined(_CE_ALLOW_SINGLE_THREADED_OBJECTS_IN_MTA)
#error "Windows CE 平台(如不提供完全 DCOM 支持的 Windows Mobile 平台)上无法正确支持单线程 COM 对象。定义 _CE_ALLOW_SINGLE_THREADED_OBJECTS_IN_MTA 可强制 ATL 支持创建单线程 COM 对象实现并允许使用其单线程 COM 对象实现。rgs 文件中的线程模型已被设置为“Free”，原因是该模型是非 DCOM Windows CE 平台支持的唯一线程模型。"
#endif

using namespace ATL;


// CHelloWorldBHO

class ATL_NO_VTABLE CHelloWorldBHO :
	public CComObjectRootEx,
	public CComCoClass,
	public IObjectWithSiteImpl,
	public IDispatchImpl,
	public IDispEventImpl<1, CHelloWorldBHO, &DIID_DWebBrowserEvents2, &LIBID_SHDocVw, 1, 1>
{
public:
	CHelloWorldBHO()
	{
	}

DECLARE_REGISTRY_RESOURCEID(IDR_HELLOWORLDBHO)

DECLARE_NOT_AGGREGATABLE(CHelloWorldBHO)

BEGIN_COM_MAP(CHelloWorldBHO)
	COM_INTERFACE_ENTRY(IHelloWorldBHO)
	COM_INTERFACE_ENTRY(IDispatch)
	COM_INTERFACE_ENTRY(IObjectWithSite)
END_COM_MAP()



	DECLARE_PROTECT_FINAL_CONSTRUCT()

	HRESULT FinalConstruct()
	{
		return S_OK;
	}

	void FinalRelease()
	{
	}
 
public:

	STDMETHOD(SetSite)(IUnknown *pUnkSite);

BEGIN_SINK_MAP(CHelloWorldBHO)
    SINK_ENTRY_EX(1, DIID_DWebBrowserEvents2, DISPID_DOCUMENTCOMPLETE, OnDocumentComplete)
END_SINK_MAP()

    // DWebBrowserEvents2
    void STDMETHODCALLTYPE OnDocumentComplete(IDispatch *pDisp, VARIANT *pvarURL);

private:

    CComPtr  m_spWebBrowser;
	BOOL m_fAdvised;
};

OBJECT_ENTRY_AUTO(__uuidof(HelloWorldBHO), CHelloWorldBHO)

HelloWorldBHO.cpp：

// HelloWorldBHO.cpp : CHelloWorldBHO 的实现

#include "stdafx.h"
#include "HelloWorldBHO.h"


// CHelloWorldBHO

STDMETHODIMP CHelloWorldBHO::SetSite(IUnknown* pUnkSite)
{
    if (pUnkSite != NULL)
    {
        // Cache the pointer to IWebBrowser2.
        HRESULT hr = pUnkSite->QueryInterface(IID_IWebBrowser2, (void **)&m_spWebBrowser);
        if (SUCCEEDED(hr))
        {
            // Register to sink events from DWebBrowserEvents2.
            hr = DispEventAdvise(m_spWebBrowser);
            if (SUCCEEDED(hr))
            {
                m_fAdvised = TRUE;
            }
        }
    }
    else
    {
        // Unregister event sink.
        if (m_fAdvised)
        {
            DispEventUnadvise(m_spWebBrowser);
            m_fAdvised = FALSE;
        }

        // Release cached pointers and other resources here.
        m_spWebBrowser.Release();
    }

    // Call base class implementation.
    return IObjectWithSiteImpl::SetSite(pUnkSite);
}

void STDMETHODCALLTYPE CHelloWorldBHO::OnDocumentComplete(IDispatch *pDisp, VARIANT *pvarURL)
{
    // Retrieve the top-level window from the site.
    HWND hwnd;
    HRESULT hr = m_spWebBrowser->get_HWND((LONG_PTR*)&hwnd);
    if (SUCCEEDED(hr))
    {
        // Output a message box when page is loaded.
        MessageBox(hwnd, L"Hello World!", L"BHO", MB_OK);
    }
}

// HelloWorldBHO.cpp : CHelloWorldBHO 的实现

#include "stdafx.h"
#include "HelloWorldBHO.h"


// CHelloWorldBHO

STDMETHODIMP CHelloWorldBHO::SetSite(IUnknown* pUnkSite)
{
    if (pUnkSite != NULL)
    {
        // Cache the pointer to IWebBrowser2.
        HRESULT hr = pUnkSite->QueryInterface(IID_IWebBrowser2, (void **)&m_spWebBrowser);
        if (SUCCEEDED(hr))
        {
            // Register to sink events from DWebBrowserEvents2.
            hr = DispEventAdvise(m_spWebBrowser);
            if (SUCCEEDED(hr))
            {
                m_fAdvised = TRUE;
            }
        }
    }
    else
    {
        // Unregister event sink.
        if (m_fAdvised)
        {
            DispEventUnadvise(m_spWebBrowser);
            m_fAdvised = FALSE;
        }

        // Release cached pointers and other resources here.
        m_spWebBrowser.Release();
    }

    // Call base class implementation.
    return IObjectWithSiteImpl::SetSite(pUnkSite);
}

void STDMETHODCALLTYPE CHelloWorldBHO::OnDocumentComplete(IDispatch *pDisp, VARIANT *pvarURL)
{
    // Retrieve the top-level window from the site.
    HWND hwnd;
    HRESULT hr = m_spWebBrowser->get_HWND((LONG_PTR*)&hwnd);
    if (SUCCEEDED(hr))
    {
        // Output a message box when page is loaded.
        MessageBox(hwnd, L"Hello World!", L"BHO", MB_OK);
    }
}

dllmain.cpp：

// dllmain.cpp : DllMain 的实现。

#include "stdafx.h"
#include "resource.h"
#include "HelloWorld_i.h"
#include "dllmain.h"

CHelloWorldModule _AtlModule;

// DLL 入口点
extern "C" BOOL WINAPI DllMain(HINSTANCE hInstance, DWORD dwReason, LPVOID lpReserved)
{
    if (dwReason == DLL_PROCESS_ATTACH)
    {
        DisableThreadLibraryCalls(hInstance);
    }
    return _AtlModule.DllMain(dwReason, lpReserved);
}

// dllmain.cpp : DllMain 的实现。

#include "stdafx.h"
#include "resource.h"
#include "HelloWorld_i.h"
#include "dllmain.h"

CHelloWorldModule _AtlModule;

// DLL 入口点
extern "C" BOOL WINAPI DllMain(HINSTANCE hInstance, DWORD dwReason, LPVOID lpReserved)
{
    if (dwReason == DLL_PROCESS_ATTACH)
    {
        DisableThreadLibraryCalls(hInstance);
    }
    return _AtlModule.DllMain(dwReason, lpReserved); 
}

HelloWorld.rgs：

HKLM {
  NoRemove SOFTWARE {
    NoRemove Microsoft {
      NoRemove Windows {
        NoRemove CurrentVersion {
          NoRemove Explorer {
            NoRemove 'Browser Helper Objects' {
              ForceRemove '{22024CC8-9043-49C7-AC80-A803A2912BF6}' = s 'HelloWorldBHO' {
                val 'NoExplorer' = d '1'
              }
            }
          }
        }
      }
    }
  }
}

HKLM {
  NoRemove SOFTWARE {
    NoRemove Microsoft {   
      NoRemove Windows {
        NoRemove CurrentVersion {
          NoRemove Explorer {
            NoRemove 'Browser Helper Objects' {
              ForceRemove '{22024CC8-9043-49C7-AC80-A803A2912BF6}' = s 'HelloWorldBHO' {
                val 'NoExplorer' = d '1'
              }
            }
          }
        }
      }
    }
  }
}

目前要修改的也就那么几个文件，然后关闭安全软件，进行build，生成的dll会自动注册到注册表里去，如图：

before：

after：

然后打开IE，如图：

也可以在IE的管理加载项中看到，工具-管理加载项：

可以启用或者禁用BHO。

这样，就完成了HelloWorld版本的BHO的开发。