获取IE缓存中的文件（验证码图片）

hnyztzh 2014-08-21 12:16:30

请教一个问题：
用windows API： FindFirstUrlCacheEntry、FindNextUrlCacheEntry 读取IE缓存，在IE缓存中获取不到网页的验证码图片文件，我用httpwatch能抓取到验证码图片的URL。
不知道是什么原因获取不到验证码图片？请大牛帮忙指点如何解决获取不到验证码图片的问题!
或者说图片文件是以其他方式读取的？
代码如下：

HANDLE hCacheEnumHandle  = NULL;

	LPINTERNET_CACHE_ENTRY_INFO lpCacheEntry = NULL;

	DWORD dwTrySize = 0;    //initial buffer size

	DWORD dwEntrySize= 8192;  //initial buffer size



	// Delete index.dat if requested.

	// Be sure that index.dat is not locked.



	// Enable initial buffer size for cache entry structure. 

	lpCacheEntry = (LPINTERNET_CACHE_ENTRY_INFO) new char[dwEntrySize];

	lpCacheEntry->dwStructSize = dwEntrySize;

	dwTrySize = dwEntrySize;



	// URL search pattern (1st parameter)

	// options are:  NULL ("*.*"), "cookie:"  

	// or "visited:". 

	hCacheEnumHandle = FindFirstUrlCacheEntry(NULL /* in */ , 

		lpCacheEntry /* out */, 

		&dwTrySize /* in, out */);



	// First, obtain handle to internet cache

	// with FindFirstUrlCacheEntry 

	// for later use with FindNextUrlCacheEntry. 

	if (hCacheEnumHandle == NULL)

	{

		CString str;

		str.Format("error=%d\n",GetLastError());

		MessageBox(str,"1111111",MB_OKCANCEL);



		if (GetLastError() == ERROR_INSUFFICIENT_BUFFER)

		{

			delete [] lpCacheEntry;

			dwEntrySize = dwTrySize;

			lpCacheEntry = (LPINTERNET_CACHE_ENTRY_INFO) new char[dwEntrySize];

			lpCacheEntry->dwStructSize = dwEntrySize;



			hCacheEnumHandle = FindFirstUrlCacheEntry(NULL, lpCacheEntry , &dwTrySize);

		}

		else

		{

			goto ENDOF;

		}

	}





	if (hCacheEnumHandle)

	{

		TRACE("%s\n",lpCacheEntry->lpszSourceUrlName);

// 		if (strcmp(lpCacheEntry->lpszSourceUrlName,pszSrc) == 0)

// 		{

// 			CopyFile(lpCacheEntry->lpszLocalFileName,pszDst,FALSE);			

// 			goto ENDOF;

// 		}

	}



	// Next, use hCacheEnumHandle obtained

	// from the previous step to delete 

	// subsequent items of cache.

	while(TRUE) 

	{

		// Notice that return values of FindNextUrlCacheEntry (BOOL) and 

		// FindFirstUrlCacheEntry (HANDLE) are different.

		dwTrySize = dwEntrySize;

		BOOL bReturn = FindNextUrlCacheEntry(hCacheEnumHandle, lpCacheEntry, &dwTrySize);





		if (!bReturn)

		{

			CString str;

			str.Format("error=%d\n",GetLastError());

			MessageBox(str,"1111111",MB_OKCANCEL);





			if (GetLastError() == ERROR_INSUFFICIENT_BUFFER)

			{

				delete [] lpCacheEntry;

				dwEntrySize = dwTrySize;

				lpCacheEntry = (LPINTERNET_CACHE_ENTRY_INFO) new char[dwEntrySize];

				lpCacheEntry->dwStructSize = dwEntrySize;

				bReturn = FindNextUrlCacheEntry(hCacheEnumHandle, lpCacheEntry, &dwTrySize);

			}

			else

			{

				break;

			}

		}



		if (bReturn)

		{

			TRACE("%s\n",lpCacheEntry->lpszSourceUrlName);

// 			if (strcmp(lpCacheEntry->lpszSourceUrlName,pszSrc) == 0)

// 			{

// 				CopyFile(lpCacheEntry->lpszLocalFileName,pszDst,FALSE);

// 				break;

// 			}

		}



	} ;





ENDOF:



	if (lpCacheEntry) delete [] lpCacheEntry;

	if (hCacheEnumHandle) FindCloseUrlCache(hCacheEnumHandle);