public static int GetParentProcessId(int processId)
{
// This may be inconsistent with snapshot but when the call returns it it not guaranteed to be consistent anyway.
EnsureProcessExists(processId);
IntPtr snapshot = IntPtr.Zero;
try
{
snapshot = NativeMethods.CreateToolhelp32Snapshot(NativeMethods.TH32CS_SNAPPROCESS, 0);
if (snapshot.ToInt64() == NativeMethods.INVALID_HANDLE_VALUE)
{
throw Marshal.GetExceptionForHR(Marshal.GetHRForLastWin32Error());
}
NativeMethods.PROCESSENTRY32 pe = new NativeMethods.PROCESSENTRY32();
pe.dwSize = (uint)Marshal.SizeOf(pe);
bool found = NativeMethods.Process32First(snapshot, ref pe);
while (found)
{
if (pe.th32ProcessID == processId)
{
return((int)pe.th32ParentProcessID);
}
found = NativeMethods.Process32Next(snapshot, ref pe);
}
// Report ArgumentException(processId) in the consistent way.
NativeMethods.SetLastError(NativeMethods.ERROR_INVALID_PARAMETER);
throw Marshal.GetExceptionForHR(Marshal.GetHRForLastWin32Error());
}
finally
{
if (snapshot != IntPtr.Zero)
{
NativeMethods.CloseHandle(snapshot);
}
}
}
public static int GetParentProcessId(int processId)
{
// This may be inconsistent with snapshot but when the call returns it it not guaranteed to be consistent anyway.
EnsureProcessExists(processId);
IntPtr snapshot = IntPtr.Zero;
try
{
snapshot = NativeMethods.CreateToolhelp32Snapshot(NativeMethods.TH32CS_SNAPPROCESS, 0);
if (snapshot.ToInt64() == NativeMethods.INVALID_HANDLE_VALUE)
{
throw Marshal.GetExceptionForHR(Marshal.GetHRForLastWin32Error());
}
NativeMethods.PROCESSENTRY32 pe = new NativeMethods.PROCESSENTRY32();
pe.dwSize = (uint)Marshal.SizeOf(pe);
bool found = NativeMethods.Process32First(snapshot, ref pe);
while (found)
{
if (pe.th32ProcessID == processId)
{
return (int)pe.th32ParentProcessID;
}
found = NativeMethods.Process32Next(snapshot, ref pe);
}
// Report ArgumentException(processId) in the consistent way.
NativeMethods.SetLastError(NativeMethods.ERROR_INVALID_PARAMETER);
throw Marshal.GetExceptionForHR(Marshal.GetHRForLastWin32Error());
}
finally
{
if (snapshot != IntPtr.Zero)
{
NativeMethods.CloseHandle(snapshot);
}
}
}
