Develop Reference

SendMessage fail using RegisterWindowMessage API

I am sending a window message from a C# application to a C++ Win32 application. I am using a message via the RegisterWindowMessage() API.
The string value transfers from C# to C++, but on the C++ side I could not convert it back to a string.
C#
[DllImport("user32.dll", SetLastError = true, CharSet = CharSet.Auto)]
public static extern int SendMessage(IntPtr hWnd, int wMsg, IntPtr wParam, IntPtr lParam);
_sendMessageID = RegisterWindowMessage("WM_MSG_TEST");
public void SendMessage()
{
IntPtr buffer = Marshal.StringToBSTR("Hello");
SendMessage((IntPtr)0xffff, (int)_sendMessageID, IntPtr.Zero, buffer);
}
C++
UINT WM_MSG_AA = RegisterWindowMessage("WM_MSG_TEST");
LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
if (message == WM_MSG_TEST)
{
BSTR* pcds = (BSTR*)lParam;
}
}
Please let me know how to fix this issue?
I also refer below link for fix issue but it could't help.
C# SendMessage to C++ WinProc
Send message to a hwnd in C#
// WindowCreationCode
BOOL ProcessNextMessage()
{
MSG msg;
GetMessage(&(msg), _hWnd, 0, 0);
TranslateMessage(&(msg));
DispatchMessage(&(msg));
return TRUE;
}
int Create(){
CoInitialize(NULL);
_hInst = GetModuleHandle(NULL);
WNDCLASS wcex = { 0 };
wcex.lpfnWndProc = WndProc;
wcex.hInstance = _hInst;
wcex.lpszClassName = c_szClassName;
if (!GetClassInfo(wcex.hInstance, wcex.lpszClassName, &wcex))
{
if (!RegisterClass(&wcex))
{
return HRESULT_FROM_WIN32(GetLastError());
}
else
{
return S_OK;
}
}
else
{
return S_OK;
}
_hWnd = CreateWindowEx(
WS_EX_TOPMOST,
c_szClassName,
"ACTXAUTODRIVER",
WS_DLGFRAME ,
1, 1, 1, 1,
NULL,
NULL, _hInst, NULL);
ShowWindow(_hWnd, SW_HIDE);
while (ProcessNextMessage())
{
}
CoUninitialize();
}

You cannot send raw memory pointers across process boundaries like you are attempting to do. Even though you are converting your C# string data to a BSTR allocated by the OS, the allocated memory is still only valid in the address space of the process that allocated it.
Your string data must be marshaled from one process's address space to the other process's address space. COM handles that for you automatically when it passes BSTR values over process boundaries. But with window messages, only certain messages are marshaled automatically by the OS, and messages created with RegisterWindowMessage() are not marshaled.
For what you are attempting, use WM_COPYDATA instead, which is marshaled. However, you should NEVER broadcast (use (IntPtr)0xffff aka HWND_BROADCAST as the target window) a WM_COPYDATA message! Bad things can happen if unsuspecting apps receive WM_COPYDATA messages they are not prepared to handle correctly.
Have your C# code find the specific window it is actually interested in for your C++ app (from FindWindow/Ex(), etc) and then send WM_COPYDATA to only that window and no others. You can use RegisterWindowMessage() to create a unique value for use in the COPYDATASTRUCT::dwData field to differentiate your use of WM_COPYDATA from other people's use of WM_COPYDATA. Make your C++ code ignore any WM_COPYDATA message whose dwData value is not recognized.
Try something more like this:
[DllImport("user32.dll", SetLastError = true, CharSet = CharSet.Auto)]
public static extern int SendMessage(IntPtr hWnd, int wMsg, IntPtr wParam, IntPtr lParam);
[StructLayout(LayoutKind.Sequential)]
struct COPYDATASTRUCT
{
public IntPtr dwData;
public int cbData;
public IntPtr lpData;
}
const int WM_COPYDATA = 0x004A;
_cdsDataID = RegisterWindowMessage("WM_MSG_TEST");
public void SendMessage() {
if (_cdsDataID == IntPtr.Zero) return;
IntPtr TargetWnd = ...; // FindWindow(), etc
if (TargetWnd == IntPtr.Zero) return;
string s = "Hello";
COPYDATASTRUCT copyData = new COPYDATASTRUCT();
copyData.lpData = Marshal.StringToHGlobalUni(s);
if (copyData.lpData != IntPtr.Zero)
{
copyData.dwData = _cdsDataID;
copyData.cbData = (s.Length + 1) * 2;
IntPtr copyDataBuff = Marshal.AllocHGlobal(Marshal.SizeOf(copyData));
if (copyDataBuff != IntPtr.Zero)
{
Marshal.StructureToPtr(copyData, copyDataBuff, false);
SendMessage(TargetWnd, WM_COPYDATA, IntPtr.Zero, copyDataBuff);
Marshal.FreeHGlobal(copyDataBuff);
}
Marshal.FreeHGlobal(copyData.lpData);
}
}
const UINT uiDataID = RegisterWindowMessage("WM_MSG_TEST");
LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
if (message == WM_COPYDATA)
{
LPCOPYDATASTRUCT pcds = (LPCOPYDATASTRUCT) lParam;
if ((pcds->dwData == WM_MSG_TEST) && (WM_MSG_TEST != 0))
{
WCHAR* pstr = (WCHAR*) pcds->lpData;
...
return 0;
}
}
return DefWindowProc(hWnd, message, wParam, lParam);
}

You can transfer string with your custom message with global atom - see GlobalAddAtom API. You get integer value from GlobalAddAtom (atom number) and give the string as input parameter. Then SendMessage transmits the atom as WPARAM or LPARAM. The other side decodes the atom to string with GlobalGetAtomName. Finally call GlobalDeleteAtom to free the resource.

How to call a CPU instruction from C#?

My processor (Intel i7) supports the POPCNT instruction and I would like to call it from my C# application. Is this possible?
I believe I read somewhere that it isn't, but the JIT will invoke it if it finds it available but what function would I have to call that may be substituted with such an instruction?
Popcount is being called millions of times in a loop so I'd like to be able to have this CPU optimization if possible.

You want to play with fire, and here we like to play with fire...
class Program
{
const uint PAGE_EXECUTE_READWRITE = 0x40;
const uint MEM_COMMIT = 0x1000;
[DllImport("kernel32.dll", SetLastError = true)]
static extern IntPtr VirtualAlloc(IntPtr lpAddress, IntPtr dwSize, uint flAllocationType, uint flProtect);
private delegate int IntReturner();
static void Main(string[] args)
{
List<byte> bodyBuilder = new List<byte>();
bodyBuilder.Add(0xb8); // MOV EAX,
bodyBuilder.AddRange(BitConverter.GetBytes(42)); // 42
bodyBuilder.Add(0xc3); // RET
byte[] body = bodyBuilder.ToArray();
IntPtr buf = VirtualAlloc(IntPtr.Zero, (IntPtr)body.Length, MEM_COMMIT, PAGE_EXECUTE_READWRITE);
Marshal.Copy(body, 0, buf, body.Length);
IntReturner ptr = (IntReturner)Marshal.GetDelegateForFunctionPointer(buf, typeof(IntReturner));
Console.WriteLine(ptr());
}
}
(this small example of assembly will simply return 42... I think it's the perfect number for this answer :-) )
In the end the trick is that:
A) You must know the opcodes corresponding to the asm you want to write
B) You use VirtualAlloc to make a page of memory executable
C) In some way you copy your opcodes there
(the code was taken from http://www.cnblogs.com/netact/archive/2013/01/10/2855448.html)
Ok... the other one was as written on the site (minus an error on the uint -> IntPtr dwSize), this one is how it should be written (or at least it's a +1 compared to the original... I would encapsulate everything in a IDisposable class instead of using try... finally)
class Program
{
const uint PAGE_READWRITE = 0x04;
const uint PAGE_EXECUTE = 0x10;
const uint MEM_COMMIT = 0x1000;
const uint MEM_RELEASE = 0x8000;
[DllImport("kernel32.dll", SetLastError = true)]
static extern IntPtr VirtualAlloc(IntPtr lpAddress, IntPtr dwSize, uint flAllocationType, uint flProtect);
[DllImport("kernel32.dll", SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
static extern bool VirtualProtect(IntPtr lpAddress, IntPtr dwSize, uint flAllocationType, out uint lpflOldProtect);
[DllImport("kernel32.dll", SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
static extern bool VirtualFree(IntPtr lpAddress, IntPtr dwSize, uint dwFreeType);
private delegate int IntReturner();
static void Main(string[] args)
{
List<byte> bodyBuilder = new List<byte>();
bodyBuilder.Add(0xb8); // MOV EAX,
bodyBuilder.AddRange(BitConverter.GetBytes(42)); // 42
bodyBuilder.Add(0xc3); // RET
byte[] body = bodyBuilder.ToArray();
IntPtr buf = IntPtr.Zero;
try
{
// We VirtualAlloc body.Length bytes, with R/W access
// Note that from what I've read, MEM_RESERVE is useless
// if the first parameter is IntPtr.Zero
buf = VirtualAlloc(IntPtr.Zero, (IntPtr)body.Length, MEM_COMMIT, PAGE_READWRITE);
if (buf == IntPtr.Zero)
{
throw new Win32Exception();
}
// Copy our instructions in the buf
Marshal.Copy(body, 0, buf, body.Length);
// Change the access of the allocated memory from R/W to Execute
uint oldProtection;
bool result = VirtualProtect(buf, (IntPtr)body.Length, PAGE_EXECUTE, out oldProtection);
if (!result)
{
throw new Win32Exception();
}
// Create a delegate to the "function"
// Sadly we can't use Funct<int>
var fun = (IntReturner)Marshal.GetDelegateForFunctionPointer(buf, typeof(IntReturner));
Console.WriteLine(fun());
}
finally
{
if (buf != IntPtr.Zero)
{
// Free the allocated memory
bool result = VirtualFree(buf, IntPtr.Zero, MEM_RELEASE);
if (!result)
{
throw new Win32Exception();
}
}
}
}
}

c# readprocessmemory with Cheat Engine

I'm trying to get string value from address which i found using cheat engine. I found for example 0x01742A38 and this is main part of my program (regular windows form application):
Process[] processes = Process.GetProcessesByName("Tibia");
foreach (Process p in processes)
{
IntPtr windowHandle = p.MainWindowHandle;
byte[] bufor = new byte[50];
uint baseAddress = (uint)p.MainModule.BaseAddress.ToInt32();
IntPtr addr = ((IntPtr)(baseAddress + 0x01742A38));
uint o = 0;
UInt32 k = 30;
if (ReadProcessMemory(windowHandle, addr, bufor, k, ref o))
{
label3.Text = "Success!";
}
else
{
label3.Text = "Fail : (";
}
}

Assuming your static address is correct, you have to open the target process using the OpenProcess function with at least the right PROCESS_VM_READ (0x0010).
I also suggest you to use a more suitable pinvoke signature for the function ReadProcessMemory:
[DllImport("kernel32.dll", SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
public static extern bool ReadProcessMemory(IntPtr hProcess, IntPtr lpBaseAddress, [Out] byte[] lpBuffer, int dwSize, out IntPtr lpNumberOfBytesRead);

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

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);