继承DWebBrowserEvents2,IWebBrowser2控件窗口类如何得到Javascript事件，执行Javascript事件

[iery]

继承DWebBrowserEvents2,IWebBrowser2控件窗口类如何得到Javascript事件，执行Javascript事件

[kalakala]

up

[grantchan]

up

[cjwn]

gz

[蒋晟]

IWebBrowser2是接口不是控件
可以得到元素事件的接口，但是Javascript本身没有事件
事件不能被执行，只能被触发。触发条件随元素和事件而异。

[天限天空]

试一试 active script 技术

[cjwn]

俺 找到了一个相关的例子。我发给你。
楼主email地址多少？

[atEleven]

我以前写过,用了一个BT 的方法实现.

javascript是在网页中的.事件发生的时候,就设置document.location到一个定义的字符串
当事件发生的时候,WebBrowser会企图Navigate到那个网址

在IWebBrowser2 的BeforeNavigate 事件中根据Navigate URL
判断是发生了哪些脚本事件并执行事件代码.同时Cancel掉该 Navigate 动作.

[cjwn]

我找到一个例子。搂主要的话留个email
我忘了在那个网站下的了。所以无法贴出地址。

[grantchan]

[e-mail]

[histimes]

这是CodeGuru上的一片文章，对你有用：
Introduction
Sometimes, when we are using the IE Browser Control inside of a C++ application, we need to access the HTML elements. We can do it by using standard COM objects such as IWebBrowser2, IHTMLDocument2, and so forth. By doing this, we easily can implement features such as click button, click anchor, get input string, get HTML text, and so on. Unfortunately, Microsoft did not provide similar objects for JavaScript. In any case, it is possible to make a control for the JavaScript object inside an HTML page by using a traditional COM approach. This article describes the class CWebPage that allows you to do it and a technique to call a JavaScript function from C++ code.

How to Do This
As the result of using the presented class, it will be easy to call any JavaScript function from C++ code. To implement this feature, we should get a pointer to the IHTMLDocument2 interface. If we are using the CHtmlView class from MFC, we can get one by using member function CHtmlView::GetHtmlDocument(). In the case of using the IWebBrowser or IWebBrowser2 components, the function get_Document will bring us the desired interface. Here is an example:

CComPtr<IDispatch> spDisp = CHtmlView::GetHtmlDocument();
m_webPage.SetDocument(spDisp);
从IWebBrowser得到IHTMLDocument2

The rest of the things will be done by the CWebPage class. Here is an example of a JavaScript call without parameters.

m_webPage.CallJScript("Welcome");

The example of the JavaScript call with two parameters will look like this:

m_webPage.CallJScript("Miltiply","2.34","3.32");

The Class Implementation
class CWebPage
{
public:
CWebPage();
virtual ~CWebPage();

bool SetDocument(IDispatch* pDisp);
LPDISPATCH GetHtmlDocument() const;
const CString GetLastError() const;
bool GetJScript(CComPtr<IDispatch>& spDisp);
bool GetJScripts(CComPtr<IHTMLElementCollection>& spColl);
CString ScanJScript(CString& strAText,CStringArray& args);

bool CallJScript(const CString strFunc);
bool CallJScript(const CString strFunc,const CString strArg1);
bool CallJScript(const CString strFunc,const CString strArg1,
const CString strArg2);
bool CallJScript(const CString strFunc,const CString strArg1,
const CString strArg2,const CString strArg3);
bool CallJScript(const CString strFunc,const
CStringArray& paramArray);

protected

CComPtr<IHTMLDocument2> m_spDoc;

};

Calling Technique
The previously mentioned technique splits the following steps:

Getting a pointer to the IHTMLDocument2 interface.
Getting IDispatch for a JavaScript object in an HTML document.
Getting DISPID for a given name of a JavaScript function.
Putting parameters to the DISPPARAM structure.
Calling a JavaScript function by using the Invoke method of the IDispatch interface.
Here is an example of getting a IDispatch pointer to the Java Scripts objects:

bool CWebPage::GetJScript(CComPtr<IDispatch>& spDisp)
{
HRESULT hr = m_spDoc->get_Script(&spDisp);
ATLASSERT(SUCCEEDED(hr));
return SUCCEEDED(hr);
}

And here is the final function to call JavaScript:

CComVariant CWebPage::CallJScript(const CString strFunc,
const CStringArray&
paramArray)
{
//Getting IDispatch for Java Script objects
CComPtr<IDispatch> spScript;
if(!GetJScript(spScript))
{
ShowError("Cannot GetScript");
return false;
}
//Find dispid for given function in the object
CComBSTR bstrMember(strFunc);
DISPID dispid = NULL;
HRESULT hr = spScript->GetIDsOfNames(IID_NULL,&bstrMember,1,
LOCALE_SYSTEM_DEFAULT,&dispid);
if(FAILED(hr))
{
ShowError(GetSystemErrorMessage(hr));
return false;
}

const int arraySize = paramArray.GetSize();
//Putting parameters
DISPPARAMS dispparams;
memset(&dispparams, 0, sizeof dispparams);
dispparams.cArgs = arraySize;
dispparams.rgvarg = new VARIANT[dispparams.cArgs];
dispparams.cNamedArgs = 0;

for( int i = 0; i < arraySize; i++)
{
CComBSTR> bstr = paramArray.GetAt(arraySize - 1 - i);
// back reading
bstr.CopyTo(&dispparams.rgvarg[i].bstrVal);
dispparams.rgvarg[i].vt = VT_BSTR;
}
EXCEPINFO excepInfo;
memset(&excepInfo, 0, sizeof excepInfo);
CComVariant vaResult;
UINT nArgErr = (UINT)-1; // initialize to invalid arg
//Call JavaScript function
hr = spScript->Invoke(dispid,IID_NULL,0,
DISPATCH_METHOD,&dispparams,
&vaResult,&excepInfo,&nArgErr);
delete [] dispparams.rgvarg;
if(FAILED(hr))
{
ShowError(GetSystemErrorMessage(hr));
return false;
}
return vaResult;
}

Notes About the Demo
To call a JavaScript function from the demo, you should select the function in the tree of the left window. After this, press the ! button on the menu bar.

Downloads
Download demo project - 34 Kb
Download source - 3 Kb

History
Date Posted: October 25, 2002


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