这似乎与 ASP.NET 管道中的无 Cookie 会话有关。它在处理请求时去除 CookielessHelper.cs (System.Web.Security) 中的 URL 模式：
// This function is called for all requests -- it must be performant.
// In the common case (i.e. value not present in the URI, it must not
// look at the headers collection
internal void RemoveCookielessValuesFromPath()
{
// See if the path contains "/(XXXXX)/"
string path = _Context.Request.ClientFilePath.VirtualPathString;
// Optimize for the common case where there is no cookie
if (path.IndexOf('(') == -1) {
return;
}
int endPos = path.LastIndexOf(")/", StringComparison.Ordinal);
int startPos = (endPos > 2 ? path.LastIndexOf("/(", endPos - 1, endPos, StringComparison.Ordinal) : -1);
if (startPos < 0) // pattern not found: common case, exit immediately
return;
if (_Headers == null) // Header should always be processed first
GetCookielessValuesFromHeader();
// if the path contains a cookie, remove it
if (IsValidHeader(path, startPos + 2, endPos))
{
// only set _Headers if not already set
if (_Headers == null) {
_Headers = path.Substring(startPos + 2, endPos - startPos - 2);
}
// Rewrite the path
path = path.Substring(0, startPos) + path.Substring(endPos+1);
// remove cookie from ClientFilePath
_Context.Request.ClientFilePath = VirtualPath.CreateAbsolute(path);
// get and append query string to path if it exists
string rawUrl = _Context.Request.RawUrl;
int qsIndex = rawUrl.IndexOf('?');
if (qsIndex > -1) {
path = path + rawUrl.Substring(qsIndex);
}
// remove cookie from RawUrl
_Context.Request.RawUrl = path;
if (!String.IsNullOrEmpty(_Headers)) {
_Context.Request.ValidateCookielessHeaderIfRequiredByConfig(_Headers); // ensure that the path doesn't contain invalid chars
_Context.Response.SetAppPathModifier("(" + _Headers + ")");
// For Cassini and scenarios where aspnet_filter.dll is not used,
// HttpRequest.FilePath also needs to have the cookie removed.
string filePath = _Context.Request.FilePath;
string newFilePath = _Context.Response.RemoveAppPathModifier(filePath);
if (!Object.ReferenceEquals(filePath, newFilePath)) {
_Context.RewritePath(VirtualPath.CreateAbsolute(newFilePath),
_Context.Request.PathInfoObject,
null /*newQueryString*/,
false /*setClientFilePath*/);
}
}
}
}
你的模式符合这个：
///////////////////////////////////////////////////////////////////////
///////////////////////////////////////////////////////////////////////
// Make sure sub-string if of the pattern: A(XXXX)N(XXXXX)P(XXXXX) and so on.
static private bool IsValidHeader(string path, int startPos, int endPos)
{
if (endPos - startPos < 3) // Minimum len is "X()"
return false;
while (startPos <= endPos - 3) { // Each iteration deals with one "A(XXXX)" pattern
if (path[startPos] < 'A' || path[startPos] > 'Z') // Make sure pattern starts with a capital letter
return false;
if (path[startPos + 1] != '(') // Make sure next char is '('
return false;
startPos += 2;
bool found = false;
for (; startPos < endPos; startPos++) { // Find the ending ')'
if (path[startPos] == ')') { // found it!
startPos++; // Set position for the next pattern
found = true;
break; // Break out of this for-loop.
}
if (path[startPos] == '/') { // Can't contain path separaters
return false;
}
}
if (!found) {
return false; // Ending ')' not found!
}
}
if (startPos < endPos) // All chars consumed?
return false;
return true;
}