我们一直在使用IHTMLElement和IHTMLElement2脚本接口来访问Web对象及其属性。现在，我们处于一种情况下，想知道元素所占用的客户区域，减去边框和滚动条所占据的任何区域。我遇到了HTMLDocument类，该类具有方法ClientRectangle（）。它的文档听起来与我们正在寻找的非常相似。我真的不确定如何访问此方法（如果可能的话）。
任何人都可以知道是否可以创建此HTMLDocument类的实例并访问其方法吗？
链接到我在说的该类的MSDN文档。
http://msdn.microsoft.com/en-us/library/system.windows.forms.htmlelement.clientrectangle.aspx?cs-save-lang=1&cs-lang=cpp#code-snippet-1
最佳答案
由于您的问题有些广泛，因此我提供的解决方案有些大，但已完成并经过测试。如果您已经有一个指向有效IHTMLDocument或IHTMLElement对象的指针，则可以很容易地检索元素的位置和尺寸。获取尺寸的唯一要求是必须将文档附加到IHTMLWindow / IWebBrowser对象。我包括一个站立功能，该功能创建IWebBrowser和IHTMLDocument对象进行测试。
我提供了一些评论，以帮助您一路走好。这已在带有Internet Explorer 9的Windows 7系统上的Visual Studio 2010中进行了测试。这是我从示例中获得的结果集：
矩形= x = 8 y = 89宽度= 992高度= 31
内容=你好
#include <comutil.h> // _bstr_t
#include <mshtml.h> // IHTMLDocument and IHTMLElement
#include <exdisp.h> // IWebBrowser2
#include <atlbase.h> // CComPtr
#include <string>
#include <iostream>
// Make sure we link in the support library!
#pragma comment(lib, "comsuppw.lib")
static const std::wstring
exampleHtml(L"<body><html><br><br><p id=\"someid\">hello</p></body>");
HRESULT CreateBrowserDocument(
const std::wstring& html,
CComPtr<IWebBrowser2>& returnBrowser,
CComPtr<IHTMLDocument3>& returnDoc);
int main()
{
///////////////////////////////////////////////////////////////////////////
// In order to get the position and dimension of an element we need to
// have a browser object that owns the document we will work on. If you
// create and use a IHTMLDocument object through CoCreateInstance it does
// not have any rendering capabilities by default.
///////////////////////////////////////////////////////////////////////////
HRESULT hr;
hr = CoInitialize(NULL);
if(SUCCEEDED(hr))
{
// Make sure these two items are scoped so CoUninitialize doesn't gump
// us up.
CComPtr<IWebBrowser2> browser;
CComPtr<IHTMLDocument3> document;
hr = CreateBrowserDocument(exampleHtml, browser, document);
if(SUCCEEDED(hr))
{
CComPtr<IHTMLElement> element;
///////////////////////////////////////////////////////////////////
// We grab the element by id to make the example easier. in some
// cases you may need to iterate through all of the elements of the
// document or parent element to find the one you want the
// dimensions for.
///////////////////////////////////////////////////////////////////
hr = document->getElementById(_bstr_t(L"someid"), &element);
if(SUCCEEDED(hr) && element != NULL)
{
///////////////////////////////////////////////////////////////
// Now that we have the browser object, document object and the
// element we want to get the dimensions for .... do it the
// easy way.
///////////////////////////////////////////////////////////////
_bstr_t contents;
long left, top, width, height;
// I skip the error checking here. Add it when you implement
// your solution.
hr = element->get_innerHTML(contents.GetAddress());
hr = element->get_offsetLeft(&left);
hr = element->get_offsetTop(&top);
hr = element->get_offsetWidth(&width);
hr = element->get_offsetHeight(&height);
std::cout
<< "Rect = "
<< "x=" << left << " "
<< "y=" << top << " "
<< "width=" << width << " "
<< "height=" << height << std::endl
<< "contents=" << contents << std::endl;
}
}
}
CoUninitialize();
return 0;
}
// Here we create web browser and document objects. The additional browser
// object is required for layout management. I have taken a shortcut here and
// create an instance Internet Explorer instead. This allows the browser to
// create and initializes a HTMLDocument when we call IWebBrowser::Navigate.
HRESULT CreateBrowserDocument(
const std::wstring& html,
CComPtr<IWebBrowser2>& returnBrowser,
CComPtr<IHTMLDocument3>& returnDoc)
{
CComPtr<IHTMLDocument2> document;
CComPtr<IWebBrowser2> browser;
HRESULT hr;
hr = CoCreateInstance(
CLSID_InternetExplorer,
NULL,
CLSCTX_SERVER,
IID_IWebBrowser2,
reinterpret_cast<void**>(&browser));
if(SUCCEEDED(hr))
{
// The browser does not contain a document by default. We can force
// one though by navigating to the `about` page. This is fast and
// does not require an internet connection.
VARIANT empty;
VariantInit(&empty);
hr = browser->Navigate(
_bstr_t(L"about:"), &empty, &empty, &empty, &empty);
// Wait for the load.
if(SUCCEEDED(hr))
{
READYSTATE state;
while(SUCCEEDED(hr = browser->get_ReadyState(&state)))
{
if(state == READYSTATE_COMPLETE) break;
}
}
// The browser now has a document object. Grab it.
if(SUCCEEDED(hr))
{
CComPtr<IDispatch> dispatch;
hr = browser->get_Document(&dispatch);
if(SUCCEEDED(hr) && dispatch != NULL)
{
hr = dispatch.QueryInterface<IHTMLDocument2>(&document);
}
else
{
hr = E_FAIL;
}
}
}
if(SUCCEEDED(hr))
{
// Since the about page is empty we can just write out our test HTML
// directly to the document. Takes some effort since we need to
// use a safe array to send it to the document.
SAFEARRAY *pString = SafeArrayCreateVector(VT_VARIANT, 0, 1);
if (pString != NULL)
{
VARIANT *param;
hr = SafeArrayAccessData(pString, reinterpret_cast<void**>(¶m));
if(SUCCEEDED(hr))
{
const _bstr_t htmlString(SysAllocString(html.c_str()));
param->vt = VT_BSTR;
param->bstrVal = htmlString;
hr = SafeArrayUnaccessData(pString);
if(SUCCEEDED(hr))
{
hr = document->write(pString);
document->close();
}
}
SafeArrayDestroy(pString);
}
// Set the return values
if(SUCCEEDED(hr) && document != NULL && browser != NULL)
{
CComPtr<IHTMLDocument3> temp;
hr = document.QueryInterface<IHTMLDocument3>(&temp);
if(SUCCEEDED(hr) && temp != NULL)
{
document = temp;
}
else
{
hr = E_FAIL;
}
CComPtr<IHTMLDocument3> tempDoc;
if(SUCCEEDED(hr))
{
hr = document.QueryInterface<IHTMLDocument3>(&tempDoc);
}
if(SUCCEEDED(hr) && tempDoc != NULL)
{
returnDoc = tempDoc;
returnBrowser = browser;
}
}
else if(!FAILED(hr))
{
hr = E_FAIL;
}
}
return hr;
}
[编辑1：删除了对
IWebBrowser::put_RegisterAsBrowser的不必要的调用][编辑2：通过使用
IHTMLElement::get_OffsetXXX代替IHTMLElement::get_clientXXX简化了尺寸获取。]