InternetReadFile 仅读取 10kb
我正在尝试使用 WinINet 库调用从 http 服务器下载文件。它在我的本地网络服务器上运行得很好。但是当我尝试从互联网下载某些内容时，InternetReadFile 只能读取约 10kb 的任何文件（文本或二进制）。在下面的示例中，TRANSFER_SIZE = 4096，因此有两次 4kb 读取和一次 2kb 读取。每个下一个 InternetReadFile 返回 true 并读取 0 个字节。
hInternet = InternetOpen(L"Agent", INTERNET_OPEN_TYPE_PRECONFIG, NULL, NULL, 0);
DWORD options = INTERNET_FLAG_NEED_FILE|INTERNET_FLAG_HYPERLINK|INTERNET_FLAG_RESYNCHRONIZE|INTERNET_FLAG_RELOAD;
HINTERNET hSession = InternetOpenUrl(hInternet, URL, NULL, NULL, options, 0);
hFile = CreateFile(...);
...
do {
DWORD dwWriteSize, dwNumWritten;
BOOL bRead = InternetReadFile(hSession, pBuf, TRANSFER_SIZE, &dwReadSizeOut);
dwWriteSize = dwReadSizeOut;
if (bRead && dwReadSizeOut > 0) {
dwTotalReadSize += dwReadSizeOut;
WriteFile(hFile, pBuf, dwWriteSize, &dwNumWritten, NULL);
// File write error
if (dwWriteSize != dwNumWritten) {
CloseHandle(hFile);
return false;
}
}
else {
if (!bRead)
{
// Error
CloseHandle(hFile);
return false;
}
break;
}
} while(1);
如何使用 WinINet 库下载整个文件？
i'm trying to download file from http server using WinINet library calls. It works perfectly fine on my local web server. but when i'm trying download something from the internet, InternetReadFile reads only ~10kb of any file (text or binary). TRANSFER_SIZE = 4096 in the example below, thus there are two reads by 4kb and one by 2kb. Every next InternetReadFile returns true and 0 bytes read.
hInternet = InternetOpen(L"Agent", INTERNET_OPEN_TYPE_PRECONFIG, NULL, NULL, 0);
DWORD options = INTERNET_FLAG_NEED_FILE|INTERNET_FLAG_HYPERLINK|INTERNET_FLAG_RESYNCHRONIZE|INTERNET_FLAG_RELOAD;
HINTERNET hSession = InternetOpenUrl(hInternet, URL, NULL, NULL, options, 0);
hFile = CreateFile(...);
...
do {
DWORD dwWriteSize, dwNumWritten;
BOOL bRead = InternetReadFile(hSession, pBuf, TRANSFER_SIZE, &dwReadSizeOut);
dwWriteSize = dwReadSizeOut;
if (bRead && dwReadSizeOut > 0) {
dwTotalReadSize += dwReadSizeOut;
WriteFile(hFile, pBuf, dwWriteSize, &dwNumWritten, NULL);
// File write error
if (dwWriteSize != dwNumWritten) {
CloseHandle(hFile);
return false;
}
}
else {
if (!bRead)
{
// Error
CloseHandle(hFile);
return false;
}
break;
}
} while(1);
How can i download the entire file using WinINet library?
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尝试在 InternetOpenURl 上设置 INTERNET_FLAG_KEEP_CONNECTION。
打开后，您还应该至少在句柄上执行 HttpQueryInfo(HTTP_QUERY_STATUS_CODE | HTTP_QUERY_FLAG_NUMBER) 操作。
我建议查看一些现有的 C++ 包装类来处理这些事情，
http://www.google .com/codesearch#search/&q=INTERNET_FLAG_KEEP_CONNECTION%20lang:c%2B%2B&type=cs
Try setting INTERNET_FLAG_KEEP_CONNECTION on InternetOpenURl.
You should also be doing at least HttpQueryInfo(HTTP_QUERY_STATUS_CODE | HTTP_QUERY_FLAG_NUMBER) on the handle after opening.
I would suggest looking at some existing wrapper C++ classes to these things,
http://www.google.com/codesearch#search/&q=INTERNET_FLAG_KEEP_CONNECTION%20lang:c%2B%2B&type=cs
我以文本形式读取响应，这是来自网络服务器的“404 错误”响应 - 文件丢失。因此，阅读回复很有用；）
libcurl 看起来像是 WinINet 库的不错替代品 - 更容易上手，有很多选项。
I read the response as text and it was the "404 error" respond from the web server - file was missing. So it's useful to read the responses ;)
And libcurl looks like nice replacement of the WinINet library - easier to start with, a lot of options.