QueryDisplayConfig() does not initialize pathArray and modeArray correctly

QueryDisplayConfig() does not initialize pathArray and modeArray correctly - c#

I'm trying to set-up an easy 1-click change of the mode of my screens (extended <--> disconnected)
but my screens are assigned no ID by the QueryDisplayConfig method.
(I'm using the User32 PInvoke lib from https://github.com/AArnott/pinvoke, in addition to what you can find in the code below)
I tried:
stepping through the code with breakpoints, making sure EVERY value is the default value.
elevating VS to run with administrator privileges.
making extra sure that the flags and errors are functioning correctly.
[DllImport("User32.dll")]
public static extern int GetDisplayConfigBufferSizes(uint flags, ref uint numPathArrayElements, ref uint numModeInfoArrayElements);
[DllImport("User32.dll")]
public static extern int QueryDisplayConfig(
uint flags,
ref uint numPathArrayElements, DISPLAYCONFIG_PATH_INFO[] pathArray,
ref uint numModeInfoArrayElements, DISPLAYCONFIG_MODE_INFO[] modeInfoArray,
DISPLAYCONFIG_TOPOLOGY_ID[] currentTopologyId
);
const int QDC_ALL_PATHS = 1;
const int QDC_ONLY_ACTIVE_PATHS = 2;
const int QDC_DATABASE_CURRENT = 4;
public static void CheckDisplays() {
uint numPathArrayElements = 0;
uint numModeInfoArrayElements = 0;
uint filter = QDC_ONLY_ACTIVE_PATHS;
int bufferError = GetDisplayConfigBufferSizes(filter, ref numPathArrayElements, ref numModeInfoArrayElements);
DISPLAYCONFIG_PATH_INFO[] pathArray = new DISPLAYCONFIG_PATH_INFO[numPathArrayElements];
DISPLAYCONFIG_MODE_INFO[] modeArray = new DISPLAYCONFIG_MODE_INFO[numModeInfoArrayElements];
int queryError = QueryDisplayConfig(filter, ref numPathArrayElements, pathArray, ref numModeInfoArrayElements, modeArray, null);
Console.WriteLine();
Console.WriteLine("Elements: " + numPathArrayElements); // Prints the correct amount of connected screens.
Console.WriteLine("BUFFER ERROR: " + bufferError); // Prints 0 -- as in Success.
Console.WriteLine("PATH ERROR: " + queryError); // Prints 0 -- as in Success.
for (int i = 0; i < pathArray.Length; i++) {
if (pathArray[i].sourceInfo.id != 0) { Console.WriteLine($"Path{i} has been initialized correctly!!"); }
// Every object in the array has default values and IDs of 0.
// Nothing prints here.
}
}
Each screen should be assigned an ID and a proper mode.
Instead, everything has the default value and I seem to be stuck.

Your declaration for QueryDisplayConfig is wrong : arrays must be [Out]
This works for me :
(I have only 1 monitor but the values received in arrays are the same as in C++ (I translated structures from SDK headers))
(IntPtr.Zero for currentTopologyId with QDC_ONLY_ACTIVE_PATHS)
[DllImport("User32.dll", SetLastError = true, CharSet = CharSet.Unicode)]
public static extern int QueryDisplayConfig(uint flags, ref uint numPathArrayElements, [Out] DISPLAYCONFIG_PATH_INFO[] pathArray,
ref uint modeInfoArrayElements, [Out] DISPLAYCONFIG_MODE_INFO[] modeInfoArray, IntPtr currentTopologyId);

Related

C# - Accessing Raw Sectors in high offset (over 4G) on external HDD

I am using in my program "Kernel32.dll" functionality to access raw disk sectors on WinXP SP3 OS (external HDD).
Everything works fine till the program reaches sector number 8388607 - which means the bytes offset in SetFilePointer exceeds 32 bit (uint!).
But my code, as below, uses all variables as "long". What I am doing wrong?
The code (on "Dump" button click):
int drive = DRV.SelectedIndex; // DRV is the drive combo box
long bps = BytesPerSector(drive), spt = GetTotalSectors(drive);
string dr = DRV.SelectedItem.ToString();
int moveToHigh, read = 0;
uint GENERIC_READ = 0x80000000;
uint OPEN_EXISTING = 3;
SafeFileHandle handleValue = CreateFile(dr, GENERIC_READ, 0, IntPtr.Zero, OPEN_EXISTING, 0, IntPtr.Zero);
if (handleValue.IsInvalid)
Marshal.ThrowExceptionForHR(Marshal.GetHRForLastWin32Error());
// idx = Loop starting index
// FS = The starting sector index
// TS = The final sector index
long idx = (FS == -1) ? 0 : FS, tot = (TS == -1) ? spt : TS;
for ( ; idx < tot; idx++)
{
byte[] b = new byte[bps];
// HERE IS THE ISSUE!!!
SetFilePointer(handleValue, idx*bps), out moveToHigh, EMoveMethod.Current);
if (ReadFile(handleValue, b, bps, out read, IntPtr.Zero) == 0)
Marshal.ThrowExceptionForHR(Marshal.GetHRForLastWin32Error());
if (this.IsDisposed == true) { handleValue.Close(); break; }
Application.DoEvents();
}
handleValue.Close();
The kernel32.dll external functions:
[DllImport("Kernel32.dll", SetLastError = true, CharSet = CharSet.Auto)]
static extern uint SetFilePointer(
[In] SafeFileHandle hFile,
[In] long lDistanceToMove,
[Out] out int lpDistanceToMoveHigh,
[In] EMoveMethod dwMoveMethod);
[DllImport("kernel32.dll", SetLastError = true, CharSet = CharSet.Unicode)]
static extern SafeFileHandle CreateFile(string lpFileName, uint dwDesiredAccess,
uint dwShareMode, IntPtr lpSecurityAttributes, uint dwCreationDisposition,
uint dwFlagsAndAttributes, IntPtr hTemplateFile);
[DllImport("kernel32", SetLastError = true)]
internal extern static int ReadFile(SafeFileHandle handle, byte[] bytes,
int numBytesToRead, out int numBytesRead, IntPtr overlapped_MustBeZero);
I have tried many things, but no idea what is wrong, application just ending up with a fatal exception asking to send bug report
Thanks a lot

Your P/Invoke definition is wrong. The function takes a 32bit value in but you defined it as a 64bit value. It won't work properly and definitely not past the value range of 32bit variables.
See the definition and example on how to use at pinvoke.net:
[DllImport("Kernel32.dll", SetLastError = true, CharSet = CharSet.Auto)]
private static extern int SetFilePointer(IntPtr handle, int lDistanceToMove, out int lpDistanceToMoveHigh, uint dwMoveMethod);
int lo = (int)(offset & 0xffffffff);
int hi = (int)(offset >> 32);
lo = SetFilePointer(handle, lo, out hi, moveMethod);
So you need to split the 64bit value in two and provide both parts for the function.
Also don't use doubles for integers. You will get into trouble when the accuracy ends and there is no reason to use them.

Pinvoke ONLY code for getting proccess via its name

as i was trying to have a test and learn about native p/invoke functions i was trying to use only pinvoke and then compare the time it takes to get process info with .net simple
Process myProc = Process.GetProcessByName("WinRAR");
though i feel that i need to realy measure that almost 2 pages in length code, using P/invoke just so i could get same results, but this time ONLY with native code, i guess that it should be faster and i want to atleast get to benchmark both ,so please help here .
so it seems that my code is 1) ... ok i guess i could count to 20
"enumerating" all it's issues, but mainly :
it doesn't enumerate all processes for a strange reason i did not see winrar for instance
second it is far from being as short as pinvoke bunche-of-methods needs
(i am using Winforms app, though you could hard code the ProcessName needed in order to "search" for the correct process)
most of comments here is by the author of well, most parts of the code
i only modified it a little to have enum later so you could choose between searching via window title or process name
so this is the code:
main entry - create instance of class :
pinvokers Pi = new pinvokers();
// Find all Internet Explorer instances(i used winrar, as my second task in this project is also test application performance... later on, and again, using only native calls)
Pi.FindWindows(0, pinvokers.SearchWin.ProcName, null, new Regex(TBX_SelectedWinName.Text), new pinvokers.FoundWindowCallback(pinvokers.foundWindowToPrint));
public class pinvokers
{
// Win32 constants.
const int WM_GETTEXT = 0x000D;
const int WM_GETTEXTLENGTH = 0x000E;
[DllImport("user32.Dll")]
private static extern Boolean EnumChildWindows(int hWndParent, PChildCallBack lpEnumFunc, int lParam);
[DllImport("user32.Dll")]
private static extern int GetWindowText(int hWnd, StringBuilder text, int count);
[DllImport("user32.Dll")]
private static extern int GetWindowThreadProcessId(int hWnd, out int lpdwProcessId);
[DllImport("user32.Dll")]
private static extern Int32 SendMessage(int hWnd, int Msg, int wParam, StringBuilder lParam);
[DllImport("user32.Dll")]
private static extern Int32 SendMessage(int hWnd, int Msg, int wParam, int lParam);
[DllImport("kernel32.dll")]
public static extern IntPtr OpenProcess(int dwDesiredAccess, bool bInheritHandle, int dwProcessId);
[DllImport("user32.dll", SetLastError = true, CharSet = CharSet.Auto)]
static extern uint GetWindowModuleFileName(IntPtr hwnd,
StringBuilder lpszFileName, uint cchFileNameMax);
[DllImport("psapi.dll")]
private static extern uint GetModuleFileNameEx(IntPtr hWnd, IntPtr hModule, StringBuilder lpFileName, int nSize);
// The PChildCallBack delegate that we used with EnumWindows.
private delegate bool PChildCallBack(int hWnd, int lParam);
// This is an event that is run each time a window was found that matches the search criterias. The boolean
// return value of the delegate matches the functionality of the PChildCallBack delegate function.
static event FoundWindowCallback foundWindowCB;
public delegate bool FoundWindowCallback(int hWnd);
int parentHandle;
Regex process;
#region <<=========== not nedded - search by window title. i am looking to search via process name ===========>>
/* <- commented all unsuesd
Regex windowText;
public static bool foundWindowToPrint(int handle)
{
// Print the window info.
printWindowInfo(handle);
// Continue on with next window.
return true;
}
static void printWindowInfo(int handle)
{
// Get the text.
int txtLength = SendMessage(handle, WM_GETTEXTLENGTH, 0, 0);
StringBuilder sbText = new StringBuilder(txtLength + 1);
SendMessage(handle, WM_GETTEXT, sbText.Capacity, sbText);
// Now we can write out the information we have on the window.
MessageBox.Show("Handle: " + handle);
MessageBox.Show("Text : " + sbText);
}
=====>end of un needed search bywindowtitle1
*/
#endregion
// my plan was to use enum instead of if !empty or null value for ither title name or process name so that's how the original code ditermin wich one to execute.
public enum SearchWin
{
Title, ProcName
}
//first method (and that's all i could really tell.. as it is full of callbacks and private extern, and delegates ... so complex
public void FindWindows(int parentHandle, SearchWin By, Regex windowText, Regex process, FoundWindowCallback fwc)
{
this.parentHandle = parentHandle;
//this.windowText = windowText;
this.process = process;
// Add the FounWindowCallback to the foundWindow event.
foundWindowCB = fwc;
// Invoke the EnumChildWindows function.
EnumChildWindows(parentHandle, new PChildCallBack(enumChildWindowsCallback), 0);
}
// This function gets called each time a window is found by the EnumChildWindows function. The foun windows here
// are NOT the final found windows as the only filtering done by EnumChildWindows is on the parent window handle.
private bool enumChildWindowsCallback(int handle, int lParam)
{
#region <<=========== not nedded - search by window title. #2 ===========>>
/* <--here too window title portion of code commented
// If a window text was provided, check to see if it matches the window.
if (windowText != null)
{
int txtLength = SendMessage(handle, WM_GETTEXTLENGTH, 0, 0);
StringBuilder sbText = new StringBuilder(txtLength + 1);
SendMessage(handle, WM_GETTEXT, sbText.Capacity, sbText);
// If it does not match, return true so we can continue on with the next window.
if (!windowText.IsMatch(sbText.ToString()))
return true;
}
*/
#endregion //endr2
// If a process name was provided, check to see if it matches the window.
if (process != null)
{
int processID;
GetWindowThreadProcessId(handle, out processID);
// Now that we have the process ID, we can use the built in .NET function to obtain a process object.
var ProcessName = GetProcNameByID(processID);
// If it does not match, return true so we can continue on with the next window.
if (!process.IsMatch(ProcessName))
return true;
}
// If we get to this point, the window is a match. Now invoke the foundWindow event and based upon
// the return value, whether we should continue to search for windows.
return foundWindowCB(handle);
}
private string GetProcNameByID(int ProcID)
{
IntPtr hProcess = OpenProcess(0x0410, false, ProcID);
StringBuilder text = new StringBuilder(1000);
GetWindowModuleFileName(hProcess, text, (uint)text.Capacity);
//GetModuleFileNameEx(hProcess, IntPtr.Zero, text, text.Capacity);
//CloseHandle(hProcess); here i am trying to catch what enumeration of windows got in its net , all this code does work just copy and paste it .
var t = text.ToString();
if (t.ToLower().Contains("inra"))
MessageBox.Show(t);
return t;
}
}
so could this be a little shorter is a side question
main one is :
Why does it not enumerate all the processes ?

i don't know if it is the best i could get or maybe someone who knows what he is doing with win api, or p/invoke or if i had to try and make unmanagedLand win over .net built in calsses
i might have rolled my sleeves and put some c++ code together (will probbably take another week)
and compile it to a dll to get all functions together in one DLL (should it do some perfomance gain)
and then i might have cut some gap .
(by the way now it is much closer to system diagnostic results thogh i thought it will be much faster and i was wrong)
but still it was only for knowing i am safe to use .net C#
and to trust microsoft for knowing much better than me (: how to make a good proggraming language.
this is the code i was using to make it through all those dllllls import. i should have known that import anything and it costs( here it might be the import tax that is costely)
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void But_StartPinvoke_Click(object sender, EventArgs e)
{
var userInputOK = TBX_SelectedProcessName.userInput();
if(!userInputOK)
MessageBox.Show(RApss.mesgs.EmptyTbx);
RApss.Strings.UserInput = TBX_SelectedProcessName.Text;
RApss.Globs.TbxPname = TBX_SelectedProcessName.Text.AddSufixEXE();
doWarmUp();
Stopwatch SwGpbn = Stopwatch.StartNew();
SwGpbn.Start();
//string _netProcName = Process.GetProcessesByName(RApss.Strings.UserInput)[0].ProcessName;
Process p = Process.GetProcessesByName(RApss.Strings.UserInput)[0];
if (p.ProcessName.ResultFetched())
SwGpbn.Stop();
var msElps_Net4 = SwGpbn.ElapsedMilliseconds;
SwGpbn.Reset();
SwGpbn.Start();
EnumProcessesV3.GetProcessByName();
SwGpbn.Stop();
var msElpsNat = SwGpbn.ElapsedMilliseconds;
SwGpbn.Reset();
SwGpbn.Reset();
if (RApss.Globs.Result.ResultFetched()) MessageBox.Show(string.Concat(RApss.Globs.Result, "\r\nWas Fetched In: ", msElpsNat, " Via PinVoke\r\n Was Fetched In: ", msElps_Net4," Via C#.NET !" ));
}
private void doWarmUp()
{
List<string> swarm = new List<string>();
for (int i = 0; i < 50000; i++)
{
swarm.Add((i + 1 *500).ToString());
}
}
}
public class RApss
{
public class Globs
{
public static string TbxPname;
public static string Result = string.Empty;
}
public class Strings
{
public static string intputForProcessName = "Requiered Process Name";
public static string UserInput = string.Empty;
}
public class mesgs
{
public static string EmptyTbx = string.Concat("please fill ", Strings.intputForProcessName, " field");
}
}
public class EnumProcessesV3
{
#region APIS
[DllImport("psapi")]
private static extern bool EnumProcesses(
[MarshalAs(UnmanagedType.LPArray, ArraySubType = UnmanagedType.U4)] [In][Out] IntPtr[] processIds,
UInt32 arraySizeBytes,
[MarshalAs(UnmanagedType.U4)] out UInt32 bytesCopied);
[DllImport("kernel32.dll")]
static extern IntPtr OpenProcess(ProcessAccessFlags dwDesiredAccess, [MarshalAs(UnmanagedType.Bool)] bool bInheritHandle, IntPtr dwProcessId);
[DllImport("kernel32.dll", SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
static extern bool CloseHandle(IntPtr hObject);
[DllImport("psapi.dll")]
static extern uint GetModuleFileNameEx(IntPtr hProcess, IntPtr hModule, [Out] StringBuilder lpBaseName, [In] [MarshalAs(UnmanagedType.U4)] int nSize);
[DllImport("psapi.dll", SetLastError = true)]
public static extern bool EnumProcessModules(IntPtr hProcess,
[Out] IntPtr lphModule,
uint cb,
[MarshalAs(UnmanagedType.U4)] out uint lpcbNeeded);
[DllImport("psapi.dll")]
static extern uint GetModuleBaseName(IntPtr hProcess, IntPtr hModule, [Out] StringBuilder lpBaseName, [In] [MarshalAs(UnmanagedType.U4)] int nSize);
#endregion
#region ENUMS
[Flags]
enum ProcessAccessFlags : uint
{
All = 0x001F0FFF,
Terminate = 0x00000001,
CreateThread = 0x00000002,
VMOperation = 0x00000008,
VMRead = 0x00000010,
VMWrite = 0x00000020,
DupHandle = 0x00000040,
SetInformation = 0x00000200,
QueryInformation = 0x00000400,
Synchronize = 0x00100000
}
#endregion
public static void GetProcessByName()
{
UInt32 arraySize = 120;
UInt32 arrayBytesSize = arraySize * sizeof(UInt32);
IntPtr[] processIds = new IntPtr[arraySize];
UInt32 bytesCopied;
bool success = EnumProcesses(processIds, arrayBytesSize, out bytesCopied);
#region <<=========== some cleanUps ============>>
// trying to check what could have been taking extra mssssnds
//Console.WriteLine("success={0}", success);
//Console.WriteLine("bytesCopied={0}", bytesCopied);
//if (!success)
//{
// MessageBox.Show("Boo!");
// return;
//}
//if (0 == bytesCopied)
//{
// MessageBox.Show("Nobody home!");
// return;
//}
#endregion
UInt32 numIdsCopied = bytesCopied >> 2;
#region <<===========same here commenting anything that might cost nerowing the options ============>>
//if (0 != (bytesCopied & 3))
//{
// UInt32 partialDwordBytes = bytesCopied & 3;
// MessageBox.Show(String.Format("EnumProcesses copied {0} and {1}/4th DWORDS... Please ask it for the other {2}/4th DWORD",
// numIdsCopied, partialDwordBytes, 4 - partialDwordBytes));
// return;
//}
//taking initialisation of SB out of loop was a winning thought but nada no change maybe in nanos
#endregion
for (UInt32 index = numIdsCopied; index> 1 ; index--) // reversing from last process id(chitting) to erlier process id did not help to win the contest
{
StringBuilder szProcessName = new StringBuilder(1000);
int x = szProcessName.Capacity;
string sName = PrintProcessName(processIds[index-1],szProcessName,x);
if (sName.Equals(RApss.Globs.TbxPname)) // tryng hardcoded value instead of reading from a variable.(GlobalsClass)
{
RApss.Globs.Result = sName;
break;
}
////////IntPtr PID = processIds[index];
////////Console.WriteLine("Name '" + sName + "' PID '" + PID + "'");
}
}
static string PrintProcessName(IntPtr processID, StringBuilder sb, int Cpcty)
{
string sName = "";
//bool bFound = false;
IntPtr hProcess = OpenProcess(ProcessAccessFlags.QueryInformation | ProcessAccessFlags.VMRead, false, processID);
if (hProcess != IntPtr.Zero)
{
IntPtr hMod = IntPtr.Zero;
uint cbNeeded = 0;
EnumProcessModules(hProcess, hMod, (uint)Marshal.SizeOf(typeof(IntPtr)), out cbNeeded);
if (GetModuleBaseName(hProcess, hMod, sb, Cpcty) > 0)
{
sName = sb.ToString();
//bFound = true;
}
// Close the process handle
CloseHandle(hProcess);
}
//if (!bFound)
//{
// sName = "<unknown>";
//}
return sName;
}
}
}
namespace RExt
{
public static class UserInputs
{
public static bool userInput(this TextBox tbxId)
{
return tbxId.Text.Length > 1;
}
}
public static class strExt
{
public static bool ResultFetched(this string StrToCheck)
{
return !string.IsNullOrWhiteSpace(StrToCheck);
}
public static string AddSufixEXE(this string StrToAppendEXE)
{
return string.Concat(StrToAppendEXE, ".exe");
}
}
}
if thats not working, make sure the project is targeting x86 CPU and Rebuild
for some reason i did not check what is needed to make it suit both x64 & x86

Navigating registry files

I am trying to read data from the registry files of other machines. Basically I have the hard drives of other systems, from which I can copy out, or directly read, for example, the SYSTEM file (Windows/system32/config/SYSTEM), so I can read data from the USBStor keys (and other stuff).
Please note I'm NOT trying to read .REG files that are exported from the registry, and NOT trying to read the the hives from the local machine. ;-)
I have been trying to find any type of library or native .Net way to do this, preferably for free! There is lots of references to reading .REG files but not the "flat" files taken from other systems.
Anyone come across this before?

Check out RegLoadKey() (MSDN here), you should be able to do something like this:
using System.Runtime.InteropServices;
using Microsoft.Win32;
namespace ConsoleApplication1
{
class Program
{
[DllImport("advapi32.dll")]
public static extern int RegLoadKey(uint hKey, string lpSubKey, string lpFile);
[DllImport("advapi32.dll")]
public static extern int RegUnLoadKey(uint hKey, string lpSubKey);
[DllImport("advapi32.dll")]
public static extern int OpenProcessToken(int ProcessHandle, int DesiredAccess, ref int tokenhandle);
[DllImport("kernel32.dll")]
public static extern int GetCurrentProcess();
[DllImport("advapi32.dll")]
public static extern int AdjustTokenPrivileges(int tokenhandle, int disableprivs, [MarshalAs(UnmanagedType.Struct)]ref TOKEN_PRIVILEGES Newstate, int bufferlength, int PreivousState, int Returnlength);
[DllImport("advapi32.dll")]
public static extern int LookupPrivilegeValue(string lpsystemname, string lpname, [MarshalAs(UnmanagedType.Struct)] ref LUID lpLuid);
[StructLayout(LayoutKind.Sequential)]
public struct LUID
{
public int LowPart;
public int HighPart;
}
[StructLayout(LayoutKind.Sequential)]
public struct TOKEN_PRIVILEGES
{
public LUID Luid;
public int Attributes;
public int PrivilegeCount;
}
static void Main(string[] args)
{
int TOKEN_ADJUST_PRIVILEGES = 0x00000020;
int SE_PRIVILEGE_ENABLED = 0x00000002;
int TOKEN_QUERY = 0x00000008;
int token = 0;
int retval = 0;
uint HKU = 0x80000003;
string SE_BACKUP_NAME = "SeBackupPrivilege";
string SE_RESTORE_NAME = "SeRestorePrivilege";
string tmpHive = "offlineSystemHive";
string offlineHive = "E:\\Windows\\system32\\config\\SYSTEM";
LUID RestoreLuid = new LUID();
LUID BackupLuid = new LUID();
TOKEN_PRIVILEGES TP = new TOKEN_PRIVILEGES();
TOKEN_PRIVILEGES TP2 = new TOKEN_PRIVILEGES();
retval = OpenProcessToken(GetCurrentProcess(), TOKEN_ADJUST_PRIVILEGES | TOKEN_QUERY, ref token);
retval = LookupPrivilegeValue(null, SE_RESTORE_NAME, ref RestoreLuid);
retval = LookupPrivilegeValue(null, SE_BACKUP_NAME, ref BackupLuid);
TP.PrivilegeCount = 1;
TP.Attributes = SE_PRIVILEGE_ENABLED;
TP.Luid = RestoreLuid;
TP2.PrivilegeCount = 1;
TP2.Attributes = SE_PRIVILEGE_ENABLED;
TP2.Luid = BackupLuid;
retval = AdjustTokenPrivileges(token, 0, ref TP, 1024, 0, 0);
retval = AdjustTokenPrivileges(token, 0, ref TP2, 1024, 0, 0);
int rtnVal = RegLoadKey(HKU, tmpHive, offlineHive);
Console.WriteLine(rtnVal); //should be 0
RegistryKey baseKey = Registry.Users.OpenSubKey("offlineSystemHive\\ControlSet001\\Control\\ComputerName\\ComputerName");
Console.WriteLine(baseKey.GetValue("ComputerName"));
baseKey.Close();
rtnVal = RegUnLoadKey(HKU, tmpHive);
Console.WriteLine(rtnVal); //should be 0
}
}
}

You need to use the RegistryKey.OpenRemoteBaseKey method explained here. Note that according to the linked msdn documentation:
In order for a key to be opened remotely, both the server and client
machines must be running the remote registry service, and have remote
administration enabled.
To enable the remote registry service, use the link Blorgbeard mentioned in the comment: http://technet.microsoft.com/en-us/library/cc754820.aspx
Here is a sample:
RegistryKey FetchedRemoteMachineKey;
FetchedRemoteMachineKey = RegistryKey.OpenRemoteBaseKey(
RegistryHive.CurrentUser, RemoteMachineName).OpenSubKey(
"Machine");

Why does my C#/pinvoke DeviceIoControl call return 0 bytes read with garbage data?

I have an unmanaged C++ Windows console app that works fine. I want it in C#. I have done DllImport statements for the necessary Kernel32.dll symbols:
[StructLayout(LayoutKind.Sequential)]
internal struct DiskGeometry
{
public long Cylinders;
public int MediaType;
public int TracksPerCylinder;
public int SectorsPerTrack;
public int BytesPerSector;
}
internal static class NativeMethods
{
internal const uint FileAccessGenericRead = 0x80000000;
internal const uint FileShareWrite = 0x2;
internal const uint FileShareRead = 0x1;
internal const uint CreationDispositionOpenExisting = 0x3;
internal const uint IoCtlDiskGetDriveGeometry = 0x70000;
[DllImport("Kernel32.dll", SetLastError = true, CharSet = CharSet.Auto)]
public static extern SafeFileHandle CreateFile(
string fileName,
uint fileAccess,
uint fileShare,
IntPtr securityAttributes,
uint creationDisposition,
uint flags,
IntPtr template);
[DllImport("Kernel32.dll", SetLastError = false, CharSet = CharSet.Auto)]
public static extern int DeviceIoControl(
SafeFileHandle device,
uint controlCode,
IntPtr inBuffer,
uint inBufferSize,
IntPtr outBuffer,
uint outBufferSize,
ref uint bytesReturned,
IntPtr overlapped);
}
I then have the following application code:
public static void Main()
{
SafeFileHandle diskHandle = NativeMethods.CreateFile(
"\\\\.\\PhysicalDrive0",
NativeMethods.FileAccessGenericRead,
NativeMethods.FileShareWrite | NativeMethods.FileShareRead,
IntPtr.Zero,
NativeMethods.CreationDispositionOpenExisting,
0,
IntPtr.Zero);
if (diskHandle.IsInvalid)
{
Console.WriteLine("CreateFile failed with error: {0}", Marshal.GetLastWin32Error());
return;
}
int geometrySize = Marshal.SizeOf(typeof(DiskGeometry));
Console.WriteLine("geometry size = {0}", geometrySize);
IntPtr geometryBlob = Marshal.AllocHGlobal(geometrySize);
uint numBytesRead = 0;
if (0 == NativeMethods.DeviceIoControl(
diskHandle,
NativeMethods.IoCtlDiskGetDriveGeometry,
IntPtr.Zero,
0,
geometryBlob,
(uint)geometrySize,
ref numBytesRead,
IntPtr.Zero))
{
Console.WriteLine("DeviceIoControl failed with error: {0}", Marshal.GetLastWin32Error());
return;
}
Console.WriteLine("Bytes read = {0}", numBytesRead);
DiskGeometry geometry = (DiskGeometry)Marshal.PtrToStructure(geometryBlob, typeof(DiskGeometry));
Marshal.FreeHGlobal(geometryBlob);
long bytesPerCylinder = (long)geometry.TracksPerCylinder * (long)geometry.SectorsPerTrack * (long)geometry.BytesPerSector;
long totalSize = geometry.Cylinders * bytesPerCylinder;
Console.WriteLine("Media Type: {0}", geometry.MediaType);
Console.WriteLine("Cylinders: {0}", geometry.Cylinders);
Console.WriteLine("Tracks per Cylinder: {0}", geometry.TracksPerCylinder);
Console.WriteLine("Sectors per Track: {0}", geometry.SectorsPerTrack);
Console.WriteLine("Bytes per Sector: {0}", geometry.BytesPerSector);
Console.WriteLine("Bytes per Cylinder: {0}", bytesPerCylinder);
Console.WriteLine("Total disk space: {0}", totalSize);
}
My C# app prints "Bytes read = 0" and the geometry member values are garbage. I am certainly no expert on DllImport and marshaling. Please help me understand what I am doing wrong. If I change the fifth parameter to DeviceIoControl to be "ref DiskGeometry" and just pass in one created right before the call (instead of IntPtr and alloc), all printed geometry member values are 0.

You have mistype, try this:
internal const uint IoCtlDiskGetDriveGeometry = 0x70000;

Try using one of those signatures for the DllImport: http://pinvoke.net/default.aspx/kernel32.DeviceIoControl

Caching and the WebBrowser control in .Net

I'm using the WebBrowser control in .Net to execute some 3rd party affiliate marketing conversions.
I have a queue table in a database with all the scripts/images to execute. I loop through all these in a WinForms app with the WebBrowser control. After I've executed a script/image I Dispose the WebBrowser control, set it to null, and renews it with a new WebBrowser control instance.
Consider this URL: http://renderserver/RenderScript.aspx?id=1
RenderScript.aspx displays an Image with a URL of e.g.: http://3rdparty/img.ashx?id=9343
I use Fiddler to see all requests and responses, and when the same URL is executed twice, it uses some kind of cache. That cache exists underneath the WebBrowser control itself.
This cache means that the img.ashx is not called.
I tried using Internet Explorer to request the URL: http://renderserver/RenderScript.aspx?id=1 and hit F5. Then it is requested perfectly.
But if I click the address bar and hits Enter to navigate to the same URL again - it is not requested. When I use Firefox is will request the page and image everytime no matter if I use F5 or navigate from the address bar.
I found some Win32 API calls (http://support.microsoft.com/kb/326201) that was able to clear the cache. It worked on my local machine. Then the app was deployed to a server running Windows Server 2003 Standard x64 (my own machine is Vista x86).
And now the API calls to clear the cache doesn't work.
Any ideas on why the API calls doesn't work on Windows Server, but works on Vista? Both machines running IE8.

I had the same problem (quite) a while back. Microsoft has a page that was very helpful with this:
http://support.microsoft.com/default.aspx?scid=http://support.microsoft.com:80/support/kb/articles/q326/2/01.asp&NoWebContent=1
I created a class out of Microsoft's sample, however I also had to add a couple if statements to stop processing when there are no more items; it's been a while now, but I'm pretty sure it would throw an error (see ERROR_NO_MORE_ITEMS in the code below).
I hope its helpful!
using System;
using System.Runtime.InteropServices;
// copied from: http://support.microsoft.com/default.aspx?scid=http://support.microsoft.com:80/support/kb/articles/q326/2/01.asp&NoWebContent=1
namespace PowerCode
{
public class IECache
{
// For PInvoke: Contains information about an entry in the Internet cache
[StructLayout(LayoutKind.Explicit, Size = 80)]
public struct INTERNET_CACHE_ENTRY_INFOA
{
[FieldOffset(0)]
public uint dwStructSize;
[FieldOffset(4)]
public IntPtr lpszSourceUrlName;
[FieldOffset(8)]
public IntPtr lpszLocalFileName;
[FieldOffset(12)]
public uint CacheEntryType;
[FieldOffset(16)]
public uint dwUseCount;
[FieldOffset(20)]
public uint dwHitRate;
[FieldOffset(24)]
public uint dwSizeLow;
[FieldOffset(28)]
public uint dwSizeHigh;
[FieldOffset(32)]
public FILETIME LastModifiedTime;
[FieldOffset(40)]
public FILETIME ExpireTime;
[FieldOffset(48)]
public FILETIME LastAccessTime;
[FieldOffset(56)]
public FILETIME LastSyncTime;
[FieldOffset(64)]
public IntPtr lpHeaderInfo;
[FieldOffset(68)]
public uint dwHeaderInfoSize;
[FieldOffset(72)]
public IntPtr lpszFileExtension;
[FieldOffset(76)]
public uint dwReserved;
[FieldOffset(76)]
public uint dwExemptDelta;
}
// For PInvoke: Initiates the enumeration of the cache groups in the Internet cache
[DllImport(#"wininet", SetLastError = true, CharSet = CharSet.Auto, EntryPoint = "FindFirstUrlCacheGroup", CallingConvention = CallingConvention.StdCall)]
public static extern IntPtr FindFirstUrlCacheGroup( int dwFlags, int dwFilter, IntPtr lpSearchCondition, int dwSearchCondition, ref long lpGroupId, IntPtr lpReserved );
// For PInvoke: Retrieves the next cache group in a cache group enumeration
[DllImport(#"wininet", SetLastError = true, CharSet = CharSet.Auto, EntryPoint = "FindNextUrlCacheGroup", CallingConvention = CallingConvention.StdCall)]
public static extern bool FindNextUrlCacheGroup( IntPtr hFind, ref long lpGroupId, IntPtr lpReserved );
// For PInvoke: Releases the specified GROUPID and any associated state in the cache index file
[DllImport(#"wininet", SetLastError = true, CharSet = CharSet.Auto, EntryPoint = "DeleteUrlCacheGroup", CallingConvention = CallingConvention.StdCall)]
public static extern bool DeleteUrlCacheGroup( long GroupId, int dwFlags, IntPtr lpReserved );
// For PInvoke: Begins the enumeration of the Internet cache
[DllImport(#"wininet", SetLastError = true, CharSet = CharSet.Auto, EntryPoint = "FindFirstUrlCacheEntryA", CallingConvention = CallingConvention.StdCall)]
public static extern IntPtr FindFirstUrlCacheEntry( [MarshalAs(UnmanagedType.LPTStr)] string lpszUrlSearchPattern, IntPtr lpFirstCacheEntryInfo, ref int lpdwFirstCacheEntryInfoBufferSize );
// For PInvoke: Retrieves the next entry in the Internet cache
[DllImport(#"wininet", SetLastError = true, CharSet = CharSet.Auto, EntryPoint = "FindNextUrlCacheEntryA", CallingConvention = CallingConvention.StdCall)]
public static extern bool FindNextUrlCacheEntry( IntPtr hFind, IntPtr lpNextCacheEntryInfo, ref int lpdwNextCacheEntryInfoBufferSize );
// For PInvoke: Removes the file that is associated with the source name from the cache, if the file exists
[DllImport(#"wininet", SetLastError = true, CharSet = CharSet.Auto, EntryPoint = "DeleteUrlCacheEntryA", CallingConvention = CallingConvention.StdCall)]
public static extern bool DeleteUrlCacheEntry( IntPtr lpszUrlName );
public static void ClearCache()
{
// Indicates that all of the cache groups in the user's system should be enumerated
const int CACHEGROUP_SEARCH_ALL = 0x0;
// Indicates that all the cache entries that are associated with the cache group
// should be deleted, unless the entry belongs to another cache group.
const int CACHEGROUP_FLAG_FLUSHURL_ONDELETE = 0x2;
// File not found.
const int ERROR_FILE_NOT_FOUND = 0x2;
// No more items have been found.
const int ERROR_NO_MORE_ITEMS = 259;
// Pointer to a GROUPID variable
long groupId = 0;
// Local variables
int cacheEntryInfoBufferSizeInitial = 0;
int cacheEntryInfoBufferSize = 0;
IntPtr cacheEntryInfoBuffer = IntPtr.Zero;
INTERNET_CACHE_ENTRY_INFOA internetCacheEntry;
IntPtr enumHandle = IntPtr.Zero;
bool returnValue = false;
// Delete the groups first.
// Groups may not always exist on the system.
// For more information, visit the following Microsoft Web site:
// http://msdn.microsoft.com/library/?url=/workshop/networking/wininet/overview/cache.asp
// By default, a URL does not belong to any group. Therefore, that cache may become
// empty even when the CacheGroup APIs are not used because the existing URL does not belong to any group.
enumHandle = FindFirstUrlCacheGroup(0, CACHEGROUP_SEARCH_ALL, IntPtr.Zero, 0, ref groupId, IntPtr.Zero);
// If there are no items in the Cache, you are finished.
if (enumHandle != IntPtr.Zero && ERROR_NO_MORE_ITEMS == Marshal.GetLastWin32Error()) {
return;
}
// Loop through Cache Group, and then delete entries.
while (true) {
if (ERROR_NO_MORE_ITEMS == Marshal.GetLastWin32Error() || ERROR_FILE_NOT_FOUND == Marshal.GetLastWin32Error()) {
break;
}
// Delete a particular Cache Group.
returnValue = DeleteUrlCacheGroup(groupId, CACHEGROUP_FLAG_FLUSHURL_ONDELETE, IntPtr.Zero);
if (!returnValue && ERROR_FILE_NOT_FOUND == Marshal.GetLastWin32Error()) {
returnValue = FindNextUrlCacheGroup(enumHandle, ref groupId, IntPtr.Zero);
}
if (!returnValue && (ERROR_NO_MORE_ITEMS == Marshal.GetLastWin32Error() || ERROR_FILE_NOT_FOUND == Marshal.GetLastWin32Error())) {
break;
}
}
// Start to delete URLs that do not belong to any group.
enumHandle = FindFirstUrlCacheEntry(null, IntPtr.Zero, ref cacheEntryInfoBufferSizeInitial);
if (enumHandle != IntPtr.Zero && ERROR_NO_MORE_ITEMS == Marshal.GetLastWin32Error()) {
return;
}
cacheEntryInfoBufferSize = cacheEntryInfoBufferSizeInitial;
cacheEntryInfoBuffer = Marshal.AllocHGlobal(cacheEntryInfoBufferSize);
enumHandle = FindFirstUrlCacheEntry(null, cacheEntryInfoBuffer, ref cacheEntryInfoBufferSizeInitial);
while (true) {
internetCacheEntry = (INTERNET_CACHE_ENTRY_INFOA)Marshal.PtrToStructure(cacheEntryInfoBuffer, typeof(INTERNET_CACHE_ENTRY_INFOA));
if (ERROR_NO_MORE_ITEMS == Marshal.GetLastWin32Error()) {
break;
}
cacheEntryInfoBufferSizeInitial = cacheEntryInfoBufferSize;
returnValue = DeleteUrlCacheEntry(internetCacheEntry.lpszSourceUrlName);
if (!returnValue) {
returnValue = FindNextUrlCacheEntry(enumHandle, cacheEntryInfoBuffer, ref cacheEntryInfoBufferSizeInitial);
}
if (!returnValue && ERROR_NO_MORE_ITEMS == Marshal.GetLastWin32Error()) {
break;
}
if (!returnValue && cacheEntryInfoBufferSizeInitial > cacheEntryInfoBufferSize) {
cacheEntryInfoBufferSize = cacheEntryInfoBufferSizeInitial;
cacheEntryInfoBuffer = Marshal.ReAllocHGlobal(cacheEntryInfoBuffer, (IntPtr)cacheEntryInfoBufferSize);
returnValue = FindNextUrlCacheEntry(enumHandle, cacheEntryInfoBuffer, ref cacheEntryInfoBufferSizeInitial);
}
}
Marshal.FreeHGlobal(cacheEntryInfoBuffer);
}
}
}
To use it in your code, just call:
IECache.ClearCache()
before calling the navigate methods.

Fiddler uses fundamentally the same code as in the KB article to clear the WinINET cache, and I use it on Win2k3 every day.
Rather than wiping the user's entire cache, the proper fix is to set the proper HTTP response header to forbid caching. You can learn more about WinINET caching here: http://www.enhanceie.com/redir/?id=httpperf
(Alternatively, you could simply add a randomized query-string parameter; that way, each time the control encounters a request for the resource, the URL is different and the cache is thus automatically bypassed.)

Try this...
[DllImport("wininet.dll", SetLastError = true)]
private static extern bool InternetSetOption(IntPtr hInternet, int dwOption, IntPtr lpBuffer, int lpdwBufferLength);
private const int INTERNET_OPTION_END_BROWSER_SESSION = 42;
private void clearCache()
{
try
{
Utilities.Web.WebBrowserHelper.WebBrowserHelper.ClearCache();
InternetSetOption(IntPtr.Zero, INTERNET_OPTION_END_BROWSER_SESSION, IntPtr.Zero, 0);
}
catch (Exception exception)
{
//throw;
}
}

That kb article everyone links to has numerous errors in it (where the selected answer's source code came from), and I've wasted ~2 days trying to get it to work in all necessary settings. It is copy pasted across the internet, and there are numerous bugs reported based on OS and IE version.
Fiddler was originally written by a Microsoft employee, and is powered by FiddlerCore.dll. Telerik (the current owners/maintainers/sellers) of Fiddler still update, maintain and give away FiddlerCore for free. If you don't want to add a reference to FiddlerCore, you can disassemble the dll, and it shows the CORRECT way to call all of these horribly documented WinINet functions, but I think posting it here would be a disservice to Telerik / plagarism.
Currently, Fiddlercore is hosted here: http://www.telerik.com/fiddler/fiddlercore

The original code from
https://support.microsoft.com/en-us/kb/326201
seems buggy
checking MSDN documentation and also the VB version here:
https://support.microsoft.com/en-us/kb/262110
I modified the code like this and now for it's working for me (the issue was on execution of FindNextUrlCacheGroup and FindNextUrlCacheEntry):
using System;
using System.Runtime.InteropServices;
namespace Q326201CS
{
// Class for deleting the cache.
public class DeleteIECache
{
// For PInvoke: Contains information about an entry in the Internet cache
[StructLayout(LayoutKind.Explicit, Size=80)]
public struct INTERNET_CACHE_ENTRY_INFOA
{
[FieldOffset(0)] public uint dwStructSize;
[FieldOffset(4)] public IntPtr lpszSourceUrlName;
[FieldOffset(8)] public IntPtr lpszLocalFileName;
[FieldOffset(12)] public uint CacheEntryType;
[FieldOffset(16)] public uint dwUseCount;
[FieldOffset(20)] public uint dwHitRate;
[FieldOffset(24)] public uint dwSizeLow;
[FieldOffset(28)] public uint dwSizeHigh;
[FieldOffset(32)] public FILETIME LastModifiedTime;
[FieldOffset(40)] public FILETIME ExpireTime;
[FieldOffset(48)] public FILETIME LastAccessTime;
[FieldOffset(56)] public FILETIME LastSyncTime;
[FieldOffset(64)] public IntPtr lpHeaderInfo;
[FieldOffset(68)] public uint dwHeaderInfoSize;
[FieldOffset(72)] public IntPtr lpszFileExtension;
[FieldOffset(76)] public uint dwReserved;
[FieldOffset(76)] public uint dwExemptDelta;
}
// For PInvoke: Initiates the enumeration of the cache groups in the Internet cache
[DllImport(#"wininet",
SetLastError=true,
CharSet=CharSet.Auto,
EntryPoint="FindFirstUrlCacheGroup",
CallingConvention=CallingConvention.StdCall)]
public static extern IntPtr FindFirstUrlCacheGroup(
int dwFlags,
int dwFilter,
IntPtr lpSearchCondition,
int dwSearchCondition,
ref long lpGroupId,
IntPtr lpReserved);
// For PInvoke: Retrieves the next cache group in a cache group enumeration
[DllImport(#"wininet",
SetLastError=true,
CharSet=CharSet.Auto,
EntryPoint="FindNextUrlCacheGroup",
CallingConvention=CallingConvention.StdCall)]
public static extern bool FindNextUrlCacheGroup(
IntPtr hFind,
ref long lpGroupId,
IntPtr lpReserved);
// For PInvoke: Releases the specified GROUPID and any associated state in the cache index file
[DllImport(#"wininet",
SetLastError=true,
CharSet=CharSet.Auto,
EntryPoint="DeleteUrlCacheGroup",
CallingConvention=CallingConvention.StdCall)]
public static extern bool DeleteUrlCacheGroup(
long GroupId,
int dwFlags,
IntPtr lpReserved);
// For PInvoke: Begins the enumeration of the Internet cache
[DllImport(#"wininet",
SetLastError=true,
CharSet=CharSet.Auto,
EntryPoint="FindFirstUrlCacheEntryA",
CallingConvention=CallingConvention.StdCall)]
public static extern IntPtr FindFirstUrlCacheEntry(
[MarshalAs(UnmanagedType.LPTStr)] string lpszUrlSearchPattern,
IntPtr lpFirstCacheEntryInfo,
ref int lpdwFirstCacheEntryInfoBufferSize);
// For PInvoke: Retrieves the next entry in the Internet cache
[DllImport(#"wininet",
SetLastError=true,
CharSet=CharSet.Auto,
EntryPoint="FindNextUrlCacheEntryA",
CallingConvention=CallingConvention.StdCall)]
public static extern bool FindNextUrlCacheEntry(
IntPtr hFind,
IntPtr lpNextCacheEntryInfo,
ref int lpdwNextCacheEntryInfoBufferSize);
// For PInvoke: Removes the file that is associated with the source name from the cache, if the file exists
[DllImport(#"wininet",
SetLastError=true,
CharSet=CharSet.Auto,
EntryPoint="DeleteUrlCacheEntryA",
CallingConvention=CallingConvention.StdCall)]
public static extern bool DeleteUrlCacheEntry(
IntPtr lpszUrlName);
public static void doDelete()
{
// Indicates that all of the cache groups in the user's system should be enumerated
const int CACHEGROUP_SEARCH_ALL = 0x0;
// Indicates that all the cache entries that are associated with the cache group
// should be deleted, unless the entry belongs to another cache group.
const int CACHEGROUP_FLAG_FLUSHURL_ONDELETE = 0x2;
// File not found.
const int ERROR_FILE_NOT_FOUND = 0x2;
// No more items have been found.
const int ERROR_NO_MORE_ITEMS = 259;
// Pointer to a GROUPID variable
long groupId = 0;
// Local variables
int cacheEntryInfoBufferSizeInitial = 0;
int cacheEntryInfoBufferSize = 0;
IntPtr cacheEntryInfoBuffer = IntPtr.Zero;
INTERNET_CACHE_ENTRY_INFOA internetCacheEntry;
IntPtr enumHandle = IntPtr.Zero;
bool returnValue = false;
// Delete the groups first.
// Groups may not always exist on the system.
// For more information, visit the following Microsoft Web site:
// http://msdn.microsoft.com/library/?url=/workshop/networking/wininet/overview/cache.asp
// By default, a URL does not belong to any group. Therefore, that cache may become
// empty even when the CacheGroup APIs are not used because the existing URL does not belong to any group.
enumHandle = FindFirstUrlCacheGroup(0, CACHEGROUP_SEARCH_ALL, IntPtr.Zero, 0, ref groupId, IntPtr.Zero);
// If there are no items in the Cache, you are finished.
if (enumHandle != IntPtr.Zero && ERROR_NO_MORE_ITEMS == Marshal.GetLastWin32Error())
return;
// Loop through Cache Group, and then delete entries.
while(true)
{
if (ERROR_NO_MORE_ITEMS == Marshal.GetLastWin32Error() || ERROR_FILE_NOT_FOUND == Marshal.GetLastWin32Error())
{
break;
}
// Delete a particular Cache Group.
returnValue = DeleteUrlCacheGroup(groupId, CACHEGROUP_FLAG_FLUSHURL_ONDELETE, IntPtr.Zero);
//if (returnValue || (!returnValue && ERROR_FILE_NOT_FOUND == Marshal.GetLastWin32Error()))
//{
returnValue = FindNextUrlCacheGroup(enumHandle, ref groupId, IntPtr.Zero);
//}
if (!returnValue && (ERROR_NO_MORE_ITEMS == Marshal.GetLastWin32Error() || ERROR_FILE_NOT_FOUND == Marshal.GetLastWin32Error()))
break;
}
// Start to delete URLs that do not belong to any group.
enumHandle = FindFirstUrlCacheEntry(null, IntPtr.Zero, ref cacheEntryInfoBufferSizeInitial);
if (enumHandle == IntPtr.Zero && ERROR_NO_MORE_ITEMS == Marshal.GetLastWin32Error())
return;
cacheEntryInfoBufferSize = cacheEntryInfoBufferSizeInitial;
cacheEntryInfoBuffer = Marshal.AllocHGlobal(cacheEntryInfoBufferSize);
enumHandle = FindFirstUrlCacheEntry(null, cacheEntryInfoBuffer, ref cacheEntryInfoBufferSizeInitial);
while(true)
{
internetCacheEntry = (INTERNET_CACHE_ENTRY_INFOA)Marshal.PtrToStructure(cacheEntryInfoBuffer, typeof(INTERNET_CACHE_ENTRY_INFOA));
if (ERROR_NO_MORE_ITEMS == Marshal.GetLastWin32Error())
{
break;
}
cacheEntryInfoBufferSizeInitial = cacheEntryInfoBufferSize;
returnValue = DeleteUrlCacheEntry(internetCacheEntry.lpszSourceUrlName);
//if (!returnValue)
//{
returnValue = FindNextUrlCacheEntry(enumHandle, cacheEntryInfoBuffer, ref cacheEntryInfoBufferSizeInitial);
//}
if (!returnValue && ERROR_NO_MORE_ITEMS == Marshal.GetLastWin32Error())
{
break;
}
if (!returnValue && cacheEntryInfoBufferSizeInitial > cacheEntryInfoBufferSize)
{
cacheEntryInfoBufferSize = cacheEntryInfoBufferSizeInitial;
cacheEntryInfoBuffer = Marshal.ReAllocHGlobal(cacheEntryInfoBuffer, (IntPtr) cacheEntryInfoBufferSize);
returnValue = FindNextUrlCacheEntry(enumHandle, cacheEntryInfoBuffer, ref cacheEntryInfoBufferSizeInitial);
}
}
Marshal.FreeHGlobal(cacheEntryInfoBuffer);
}
}
}

This should do the trick:
Response.Cache.SetCacheability(HttpCacheability.NoCache);

Develop Reference

C# (C-Sharp) is a programming language developed by Microsoft that runs on the .NET Framework.