winapi获取网络文件大小

HINTERNET hNet = ::InternetOpen(L"Internet Explorer", INTERNET_OPEN_TYPE_PRECONFIG, NULL, NULL, 0);
if (hNet == NULL) {
	MessageBoxA(NULL, "hNet is NULL", NULL, NULL);
}
HINTERNET hUrlFile = ::InternetOpenUrlA(hNet, url, NULL, 0, INTERNET_FLAG_RELOAD, 0);
if (hUrlFile == NULL) {
	MessageBoxA(NULL, "hUrlFile is NULL", NULL, NULL);
}
char buffer[100];
DWORD bufLen = sizeof(buffer);
DWORD WIndex = 0;
memset(buffer, 0, 100);
BOOL bQuery = ::HttpQueryInfoA(hUrlFile, HTTP_QUERY_CONTENT_LENGTH, buffer, &bufLen, &WIndex);
dwFileSize = (DWORD)atoi(buffer);
InternetCloseHandle(hUrlFile);
InternetCloseHandle(hNet);

主要用到HttpQueryInfoA这个函数，第三个参数是用来接收CONTENT_LENGTH的，不过要用字符数组来接收，然后再用atoi转成int类型，这样就能得到网络文件的大小了。