Develop Reference

Is there a way to use CredUIPromptForWindowsCredentialsW without unpacking the buffer (C++/CLR)?

A software I am writing is about to take an action that requires the current logged in user is actually the one taking the action. So I want to have windows just ask for the current user's password or biometrics or whatever before the action is allowed to continue.
I used an interop for UserConsentVerifier from another post (Code Below).
using System;
using System.Runtime.InteropServices;
using System.Runtime.InteropServices.WindowsRuntime;
using Windows.Foundation;
using Windows.Security.Credentials.UI;
namespace UWPInterop
{
//MIDL_INTERFACE("39E050C3-4E74-441A-8DC0-B81104DF949C")
//IUserConsentVerifierInterop : public IInspectable
//{
//public:
// virtual HRESULT STDMETHODCALLTYPE RequestVerificationForWindowAsync(
// /* [in] */ HWND appWindow,
// /* [in] */ HSTRING message,
// /* [in] */ REFIID riid,
// /* [iid_is][retval][out] */ void** asyncOperation) = 0;
//};
[System.Runtime.InteropServices.Guid("39E050C3-4E74-441A-8DC0-B81104DF949C")]
[System.Runtime.InteropServices.InterfaceType(System.Runtime.InteropServices.ComInterfaceType.InterfaceIsIInspectable)]
public interface IUserConsentVerifierInterop
{
IAsyncOperation<UserConsentVerificationResult> RequestVerificationForWindowAsync(IntPtr appWindow, [MarshalAs(UnmanagedType.HString)] string Message, [In] ref Guid riid);
}
//Helper to initialize UserConsentVerifier
public static class UserConsentVerifierInterop
{
public static IAsyncOperation<UserConsentVerificationResult> RequestVerificationForWindowAsync(IntPtr hWnd, string Message)
{
IUserConsentVerifierInterop userConsentVerifierInterop = (IUserConsentVerifierInterop)WindowsRuntimeMarshal.GetActivationFactory(typeof(UserConsentVerifier));
Guid guid = typeof(IAsyncOperation<UserConsentVerificationResult>).GUID;
return userConsentVerifierInterop.RequestVerificationForWindowAsync(hWnd, Message, ref guid);
}
}
}
This works fine if a Windows Hello is setup. It returns DeviceNotPresent when its not or similar errors. Trying to find an alternative where the windows password is provided instead. This code works but I'm not entirely happy with the fact I am using a password in the app's memory. (C++/CLR)
bool ValidateUser(String ^caption, String ^message)
{
bool result = false;
String^ userName = WindowsIdentity::GetCurrent()->Name;
std::wstring strUsername = marshal_as<std::wstring>(userName);
std::wstring strCaption = marshal_as<std::wstring>(caption);
std::wstring strMessage = marshal_as<std::wstring>(message);
CREDUI_INFOW info;
ZeroMemory(&info, sizeof(info));
info.cbSize = sizeof(info);
info.pszMessageText = strMessage.c_str();
info.pszCaptionText = strCaption.c_str();
ULONG authPackage = 0;
LPVOID pOut;
ULONG bufSize;
DWORD inBuffer = 0;
std::vector<uint8_t> credBuffer;
if (!CredPackAuthenticationBufferW(CRED_PACK_PROTECTED_CREDENTIALS, (LPWSTR)strUsername.c_str(), L"", NULL, &inBuffer)
&& ERROR_INSUFFICIENT_BUFFER == ::GetLastError())
{
credBuffer.resize(inBuffer);
if (!CredPackAuthenticationBufferW(CRED_PACK_PROTECTED_CREDENTIALS, (LPWSTR)strUsername.c_str(), L"", credBuffer.data(), &inBuffer))
{
return false;
}
}
DWORD dwResult = CredUIPromptForWindowsCredentialsW(&info, 0, &authPackage, credBuffer.data(), inBuffer, &pOut, &bufSize, NULL, CREDUIWIN_GENERIC | CREDUIWIN_IN_CRED_ONLY);
if (dwResult == ERROR_SUCCESS)
{
DWORD dwUserLength = 0;
DWORD dwDomainLength = 0;
DWORD dwPasswordLength = 0;
try
{
if (!::CredUnPackAuthenticationBufferW(CRED_PACK_PROTECTED_CREDENTIALS, pOut, bufSize, nullptr, &dwUserLength, nullptr, &dwDomainLength, nullptr, &dwPasswordLength)
&& ERROR_INSUFFICIENT_BUFFER == ::GetLastError())
{
std::vector<wchar_t> bufferUser(dwUserLength);
std::vector<wchar_t> bufferDomain(dwDomainLength);
std::vector<wchar_t> bufferPassword(dwPasswordLength);
if (::CredUnPackAuthenticationBufferW(CRED_PACK_PROTECTED_CREDENTIALS, pOut, bufSize, bufferUser.data(), &dwUserLength, bufferDomain.data(), &dwDomainLength, bufferPassword.data(), &dwPasswordLength))
{
HANDLE hToken;
std::wstring strUsername = bufferUser.data();
std::wstring strDomain;
if (bufferDomain.size() == 0)
{
std::wstring::size_type pos = strUsername.find(L'\\');
if (pos != std::wstring::npos)
{
strDomain = strUsername.substr(0, pos);
strUsername = strUsername.substr(pos + 1, strUsername.size() - pos - 1);
}
}
else
{
strDomain = bufferDomain.data();
}
try
{
if (::LogonUserW(strUsername.c_str(), strDomain.c_str(), bufferPassword.data(), LOGON32_LOGON_INTERACTIVE, LOGON32_PROVIDER_DEFAULT, &hToken))
result = true;
}
catch (...) // Catch so memory can be cleared
{
}
ClearBuffer(bufferUser.data(), dwUserLength);
ClearBuffer(bufferDomain.data(), dwDomainLength);
ClearBuffer(bufferPassword.data(), dwPasswordLength);
}
}
}
catch(...) // Catch so memory can be cleared
{
}
ClearBuffer(pOut, bufSize);
CoTaskMemFree(pOut);
}
return result;
}
Is there a way to use CredUIPromptForWindowsCredentialsW without unpacking the buffer it returns to verify the login?

RegEnumKeyEx - Access violation writing location

The situation:
Need to fetch a list of all subkeys of a particular registry key.
Need to access both 32bit and 64bit software keys, so I cannot use the Registry namespace.
Using CSharp in .Net 3.5, and registry functionality from advapi32.dll
I have most of the functionality working but I'm stuck on an error. When it reaches a key that contains values, it will either skip it or throw the following error:
"Unhandled exception at 0x00C819CD in xxxxx.exe: 0xC0000005: Access violation writing location 0x00720077."
If the error occurs, it does not land in either of my catch statements. It hard crashes the program. From what I've read on the forums, I believe it may be an issue with it writing to protected memory but all of the examples I see are for C++
My Declaration (from P/Invoke Interop Assistant):
[DllImportAttribute("advapi32.dll", EntryPoint = "RegEnumKeyExW")]
public static extern int RegEnumKeyExW(
[InAttribute()] IntPtr hKey,
uint dwIndex,
[OutAttribute()] [MarshalAsAttribute(UnmanagedType.LPWStr)] StringBuilder lpName,
ref uint lpcchName,
IntPtr lpReserved,
IntPtr lpClass,
IntPtr lpcchClass,
IntPtr lpftLastWriteTime);
My Function (obviously a work in progress so it's a bit messy):
static private List<string> GetSubKeys(UIntPtr inHive, String inKeyName, RegSAM in32or64key) {
int hkey = 0;
uint dwIndex = 0;
long enumStatus = 0;
List<string> keys = new List<string>();
try {
uint lResult = RegOpenKeyEx(
HKEY_LOCAL_MACHINE,
inKeyName,
0,
(int)RegSAM.QueryValue | (int)RegSAM.EnumerateSubKeys | (int)in32or64key,
out hkey);
if (lResult == 0) {
while (enumStatus == ERROR_SUCCESS) {
StringBuilder lpName = new StringBuilder();
uint lpcchName = 256;
IntPtr lpReserved = IntPtr.Zero;
IntPtr lpClass = IntPtr.Zero;
IntPtr lpcchClass = IntPtr.Zero;
IntPtr lpftLastWriteTime = IntPtr.Zero;
enumStatus = RegEnumKeyExW(
(IntPtr)hkey,
dwIndex,
lpName,
ref lpcchName,
lpReserved,
lpClass,
lpcchClass,
lpftLastWriteTime);
switch (enumStatus) {
case ERROR_SUCCESS:
Console.WriteLine(string.Format("Key Found: {0}", lpName.ToString()));
break;
case ERROR_NO_MORE_ITEMS:
break;
default:
string error = new System.ComponentModel.Win32Exception((int)enumStatus).Message;
Console.WriteLine(string.Format("RegEnumKeyEx Error: {0}", error));
break;
}
dwIndex++;
}
} else {
Console.WriteLine(string.Format("RegOpenKey Error: {0}", lResult));
}
} catch (System.Runtime.InteropServices.COMException ex) {
Console.WriteLine(string.Format("COM Error: {0}", ex.Message));
} catch (Exception ex) {
Console.WriteLine(string.Format("Managed Error: {0}", ex.Message));
} finally {
if (0 != hkey) RegCloseKey(hkey);
}
return keys;
}
#endregion

StringBuilder lpName = new StringBuilder();
uint lpcchName = 256;
You are lying about the StringBuilder's capacity. It is 0, not 256. This will cause the pinvoke call to corrupt the GC heap. This eventually causes a hard crash, typically when a garbage collection takes place. Fix:
uint lpcchName = 256;
StringBuilder lpName = new StringBuilder(lpcchName);
Using the .NET RegistryKey.GetSubKeyNames() method instead would probably be wise.

Use the same way as. net4.0
static void Main(string[] args)
{
string displayName;
List<string> gInstalledSoftware = new List<string>();
using (var localMachine = RegistryKey.OpenBaseKey(RegistryHive.LocalMachine, RegistryView.Registry64))
{
var key = localMachine.OpenSubKey(#"SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall", false);
foreach (String keyName in key.GetSubKeyNames())
{
RegistryKey subkey = key.OpenSubKey(keyName);
displayName = subkey.GetValue("DisplayName") as string;
if (string.IsNullOrEmpty(displayName))
continue;
gInstalledSoftware.Add(displayName);
}
}
}

You can try using. net source code to solve this problem. etc.
public class RegistryKey:
IDisposable
{
internal static readonly IntPtr HKEY_CLASSES_ROOT = new IntPtr(unchecked((int)0x80000000));
internal static readonly IntPtr HKEY_CURRENT_USER = new IntPtr(unchecked((int)0x80000001));
internal static readonly IntPtr HKEY_LOCAL_MACHINE = new IntPtr(unchecked((int)0x80000002));
internal static readonly IntPtr HKEY_USERS = new IntPtr(unchecked((int)0x80000003));
internal static readonly IntPtr HKEY_PERFORMANCE_DATA = new IntPtr(unchecked((int)0x80000004));
internal static readonly IntPtr HKEY_CURRENT_CONFIG = new IntPtr(unchecked((int)0x80000005));
private static readonly String[] hkeyNames = new String[] {
"HKEY_CLASSES_ROOT",
"HKEY_CURRENT_USER",
"HKEY_LOCAL_MACHINE",
"HKEY_USERS",
"HKEY_PERFORMANCE_DATA",
"HKEY_CURRENT_CONFIG",
};
public Object GetValue(String name)
{
return InternalGetValue(name, null, false, true);
}
internal Object InternalGetValue(String name, Object defaultValue, bool doNotExpand, bool checkSecurity)
{
Object data = defaultValue;
int type = 0;
int datasize = 0;
int ret = Win32Native.RegQueryValueEx(hkey, name, null, ref type, (byte[])null, ref datasize);
if (ret != 0)
{
if (IsPerfDataKey())
{
int size = 65000;
int sizeInput = size;
int r;
byte[] blob = new byte[size];
while (Win32Native.ERROR_MORE_DATA == (r = Win32Native.RegQueryValueEx(hkey, name, null, ref type, blob, ref sizeInput)))
{
if (size == Int32.MaxValue)
{
// ERROR_MORE_DATA was returned however we cannot increase the buffer size beyond Int32.MaxValue
//Win32Error(r, name);
Console.WriteLine(string.Format("[{0}] [{1}]", r,name));
}
else if (size > (Int32.MaxValue / 2))
{
// at this point in the loop "size * 2" would cause an overflow
size = Int32.MaxValue;
}
else
{
size *= 2;
}
sizeInput = size;
blob = new byte[size];
}
if (r != 0)
Console.WriteLine(string.Format("[{0}] [{1}]", r, name));
return blob;
}
else
{
// For stuff like ERROR_FILE_NOT_FOUND, we want to return null (data).
// Some OS's returned ERROR_MORE_DATA even in success cases, so we
// want to continue on through the function.
if (ret != Win32Native.ERROR_MORE_DATA)
return data;
}
}
if (datasize < 0)
{
// unexpected code path
//BCLDebug.Assert(false, "[InternalGetValue] RegQueryValue returned ERROR_SUCCESS but gave a negative datasize");
datasize = 0;
}
switch (type)
{
case Win32Native.REG_NONE:
case Win32Native.REG_DWORD_BIG_ENDIAN:
case Win32Native.REG_BINARY:
{
byte[] blob = new byte[datasize];
ret = Win32Native.RegQueryValueEx(hkey, name, null, ref type, blob, ref datasize);
data = blob;
}
break;
case Win32Native.REG_QWORD:
{ // also REG_QWORD_LITTLE_ENDIAN
if (datasize > 8)
{
// prevent an AV in the edge case that datasize is larger than sizeof(long)
goto case Win32Native.REG_BINARY;
}
long blob = 0;
//BCLDebug.Assert(datasize==8, "datasize==8");
// Here, datasize must be 8 when calling this
ret = Win32Native.RegQueryValueEx(hkey, name, null, ref type, ref blob, ref datasize);
data = blob;
}
break;
case Win32Native.REG_DWORD:
{ // also REG_DWORD_LITTLE_ENDIAN
if (datasize > 4)
{
// prevent an AV in the edge case that datasize is larger than sizeof(int)
goto case Win32Native.REG_QWORD;
}
int blob = 0;
// Here, datasize must be four when calling this
ret = Win32Native.RegQueryValueEx(hkey, name, null, ref type, ref blob, ref datasize);
data = blob;
}
break;
case Win32Native.REG_SZ:
{
if (datasize % 2 == 1)
{
// handle the case where the registry contains an odd-byte length (corrupt data?)
try
{
datasize = checked(datasize + 1);
}
catch (OverflowException e)
{
throw new IOException(("Arg_RegGetOverflowBug"), e);
}
}
char[] blob = new char[datasize / 2];
ret = Win32Native.RegQueryValueEx(hkey, name, null, ref type, blob, ref datasize);
if (blob.Length > 0 && blob[blob.Length - 1] == (char)0)
{
data = new String(blob, 0, blob.Length - 1);
}
else
{
// in the very unlikely case the data is missing null termination,
// pass in the whole char[] to prevent truncating a character
data = new String(blob);
}
}
break;
case Win32Native.REG_EXPAND_SZ:
{
if (datasize % 2 == 1)
{
// handle the case where the registry contains an odd-byte length (corrupt data?)
try
{
datasize = checked(datasize + 1);
}
catch (OverflowException e)
{
throw new IOException(("Arg_RegGetOverflowBug"), e);
}
}
char[] blob = new char[datasize / 2];
ret = Win32Native.RegQueryValueEx(hkey, name, null, ref type, blob, ref datasize);
if (blob.Length > 0 && blob[blob.Length - 1] == (char)0)
{
data = new String(blob, 0, blob.Length - 1);
}
else
{
// in the very unlikely case the data is missing null termination,
// pass in the whole char[] to prevent truncating a character
data = new String(blob);
}
if (!doNotExpand)
data = Environment.ExpandEnvironmentVariables((String)data);
}
break;
case Win32Native.REG_MULTI_SZ:
{
if (datasize % 2 == 1)
{
// handle the case where the registry contains an odd-byte length (corrupt data?)
try
{
datasize = checked(datasize + 1);
}
catch (OverflowException e)
{
throw new IOException(("Arg_RegGetOverflowBug"), e);
}
}
char[] blob = new char[datasize / 2];
ret = Win32Native.RegQueryValueEx(hkey, name, null, ref type, blob, ref datasize);
// make sure the string is null terminated before processing the data
if (blob.Length > 0 && blob[blob.Length - 1] != (char)0)
{
try
{
char[] newBlob = new char[checked(blob.Length + 1)];
for (int i = 0; i < blob.Length; i++)
{
newBlob[i] = blob[i];
}
newBlob[newBlob.Length - 1] = (char)0;
blob = newBlob;
}
catch (OverflowException e)
{
throw new IOException(("Arg_RegGetOverflowBug"), e);
}
blob[blob.Length - 1] = (char)0;
}
IList<String> strings = new List<String>();
int cur = 0;
int len = blob.Length;
while (ret == 0 && cur < len)
{
int nextNull = cur;
while (nextNull < len && blob[nextNull] != (char)0)
{
nextNull++;
}
if (nextNull < len)
{
//BCLDebug.Assert(blob[nextNull] == (char)0, "blob[nextNull] should be 0");
if (nextNull - cur > 0)
{
strings.Add(new String(blob, cur, nextNull - cur));
}
else
{
// we found an empty string. But if we're at the end of the data,
// it's just the extra null terminator.
if (nextNull != len - 1)
strings.Add(String.Empty);
}
}
else
{
strings.Add(new String(blob, cur, len - cur));
}
cur = nextNull + 1;
}
data = new String[strings.Count];
strings.CopyTo((String[])data, 0);
}
break;
case Win32Native.REG_LINK:
default:
break;
}
return data;
}
public String[] GetSubKeyNames()
{
return InternalGetSubKeyNames();
}
public RegistryKey OpenSubKey(string name, bool writable=false)
{
name = FixupName(name); // Fixup multiple slashes to a single slash
SafeRegistryHandle result = null;
int ret = Win32Native.RegOpenKeyEx(hkey,
name,
0,
GetRegistryKeyAccess(writable) | (int)regView,
out result);
if (ret == 0 && !result.IsInvalid)
{
RegistryKey key = new RegistryKey(result, writable, false, remoteKey, false, regView);
key.checkMode = GetSubKeyPermissonCheck(writable);
key.keyName = keyName + "\\" + name;
return key;
}
// Return null if we didn't find the key.
if (ret == Win32Native.ERROR_ACCESS_DENIED || ret == Win32Native.ERROR_BAD_IMPERSONATION_LEVEL)
{
// We need to throw SecurityException here for compatibility reasons,
// although UnauthorizedAccessException will make more sense.
//ThrowHelper.ThrowSecurityException(ExceptionResource.Security_RegistryPermission);
}
return null;
}
private const int MaxKeyLength = 255;
internal unsafe String[] InternalGetSubKeyNames()
{
int subkeys = InternalSubKeyCount();
String[] names = new String[subkeys]; // Returns 0-length array if empty.
if (subkeys > 0)
{
char[] name = new char[MaxKeyLength + 1];
int namelen;
fixed (char* namePtr = &name[0])
{
for (int i = 0; i < subkeys; i++)
{
namelen = name.Length; // Don't remove this. The API's doesn't work if this is not properly initialised.
int ret = Win32Native.RegEnumKeyEx(hkey,
i,
namePtr,
ref namelen,
null,
null,
null,
null);
if (ret != 0)
//Win32Error(ret, null);
Console.WriteLine(ret);
names[i] = new String(namePtr);
}
}
}
return names;
}
internal int InternalSubKeyCount()
{
int subkeys = 0;
int junk = 0;
int ret = Win32Native.RegQueryInfoKey(hkey,
null,
null,
IntPtr.Zero,
ref subkeys, // subkeys
null,
null,
ref junk, // values
null,
null,
null,
null);
if (ret != 0)
//Win32Error(ret, null);
Console.WriteLine(ret);
return subkeys;
}
public static RegistryKey OpenBaseKey(RegistryHive hKey, RegistryView view)
{
return GetBaseKey((IntPtr)((int)hKey), view);
}
internal static RegistryKey GetBaseKey(IntPtr hKey, RegistryView view)
{
int index = ((int)hKey) & 0x0FFFFFFF;
//BCLDebug.Assert(index >= 0 && index < hkeyNames.Length, "index is out of range!");
//BCLDebug.Assert((((int)hKey) & 0xFFFFFFF0) == 0x80000000, "Invalid hkey value!");
bool isPerf = hKey == HKEY_PERFORMANCE_DATA;
// only mark the SafeHandle as ownsHandle if the key is HKEY_PERFORMANCE_DATA.
SafeRegistryHandle srh = new SafeRegistryHandle(hKey, isPerf);
RegistryKey key = new RegistryKey(srh, true, true, false, isPerf, view);
key.checkMode = RegistryKeyPermissionCheck.Default;
key.keyName = hkeyNames[index];
return key;
}
private volatile SafeRegistryHandle hkey = null;
private volatile int state = 0;
private volatile String keyName;
private volatile bool remoteKey = false;
private volatile RegistryKeyPermissionCheck checkMode;
private volatile RegistryView regView = RegistryView.Default;
private const int STATE_DIRTY = 0x0001;
// SystemKey indicates that this is a "SYSTEMKEY" and shouldn't be "opened"
// or "closed".
//
private const int STATE_SYSTEMKEY = 0x0002;
// Access
//
private const int STATE_WRITEACCESS = 0x0004;
// Indicates if this key is for HKEY_PERFORMANCE_DATA
private const int STATE_PERF_DATA = 0x0008;
private RegistryKey(SafeRegistryHandle hkey, bool writable, bool systemkey, bool remoteKey, bool isPerfData, RegistryView view)
{
this.hkey = hkey;
this.keyName = "";
this.remoteKey = remoteKey;
this.regView = view;
if (systemkey)
{
this.state |= STATE_SYSTEMKEY;
}
if (writable)
{
this.state |= STATE_WRITEACCESS;
}
if (isPerfData)
this.state |= STATE_PERF_DATA;
}
private RegistryKeyPermissionCheck GetSubKeyPermissonCheck(bool subkeyWritable)
{
if (checkMode == RegistryKeyPermissionCheck.Default)
{
return checkMode;
}
if (subkeyWritable)
{
return RegistryKeyPermissionCheck.ReadWriteSubTree;
}
else
{
return RegistryKeyPermissionCheck.ReadSubTree;
}
}
static int GetRegistryKeyAccess(bool isWritable)
{
int winAccess;
if (!isWritable)
{
winAccess = Win32Native.KEY_READ;
}
else
{
winAccess = Win32Native.KEY_READ | Win32Native.KEY_WRITE;
}
return winAccess;
}
internal static String FixupName(String name)
{
//BCLDebug.Assert(name!=null,"[FixupName]name!=null");
if (name.IndexOf('\\') == -1)
return name;
StringBuilder sb = new StringBuilder(name);
FixupPath(sb);
int temp = sb.Length - 1;
if (temp >= 0 && sb[temp] == '\\') // Remove trailing slash
sb.Length = temp;
return sb.ToString();
}
private static void FixupPath(StringBuilder path)
{
//Contract.Requires(path != null);
int length = path.Length;
bool fixup = false;
char markerChar = (char)0xFFFF;
int i = 1;
while (i < length - 1)
{
if (path[i] == '\\')
{
i++;
while (i < length)
{
if (path[i] == '\\')
{
path[i] = markerChar;
i++;
fixup = true;
}
else
break;
}
}
i++;
}
if (fixup)
{
i = 0;
int j = 0;
while (i < length)
{
if (path[i] == markerChar)
{
i++;
continue;
}
path[j] = path[i];
i++;
j++;
}
path.Length += j - i;
}
}
#region IDisposable Support
private bool disposedValue = false; // 要检测冗余调用
public void Close()
{
Dispose(true);
}
protected virtual void Dispose(bool disposing)
{
if (hkey != null)
{
if (!IsSystemKey())
{
try
{
hkey.Dispose();
}
catch (IOException)
{
// we don't really care if the handle is invalid at this point
}
finally
{
hkey = null;
}
}
else if (disposing && IsPerfDataKey())
{
// System keys should never be closed. However, we want to call RegCloseKey
// on HKEY_PERFORMANCE_DATA when called from PerformanceCounter.CloseSharedResources
// (i.e. when disposing is true) so that we release the PERFLIB cache and cause it
// to be refreshed (by re-reading the registry) when accessed subsequently.
// This is the only way we can see the just installed perf counter.
// NOTE: since HKEY_PERFORMANCE_DATA is process wide, there is inherent race condition in closing
// the key asynchronously. While Vista is smart enough to rebuild the PERFLIB resources
// in this situation the down level OSes are not. We have a small window between
// the dispose below and usage elsewhere (other threads). This is By Design.
// This is less of an issue when OS > NT5 (i.e Vista & higher), we can close the perfkey
// (to release & refresh PERFLIB resources) and the OS will rebuild PERFLIB as necessary.
SafeRegistryHandle.RegCloseKey(RegistryKey.HKEY_PERFORMANCE_DATA);
}
}
}
private bool IsPerfDataKey()
{
return (this.state & STATE_PERF_DATA) != 0;
}
private bool IsSystemKey()
{
return (this.state & STATE_SYSTEMKEY) != 0;
}
public void Dispose()
{
Dispose(true);
}
#endregion
}
[System.Security.SecurityCritical]
public sealed class SafeRegistryHandle : SafeHandleZeroOrMinusOneIsInvalid
{
[System.Security.SecurityCritical]
internal SafeRegistryHandle() : base(true) { }
[System.Security.SecurityCritical]
public SafeRegistryHandle(IntPtr preexistingHandle, bool ownsHandle) : base(ownsHandle)
{
SetHandle(preexistingHandle);
}
[System.Security.SecurityCritical]
override protected bool ReleaseHandle()
{
return (RegCloseKey(handle) == Win32Native.ERROR_SUCCESS);
}
[DllImport(Win32Native.ADVAPI32)]
internal static extern int RegCloseKey(IntPtr hKey);
}
[Serializable]
[System.Runtime.InteropServices.ComVisible(true)]
public enum RegistryHive
{
ClassesRoot = unchecked((int)0x80000000),
CurrentUser = unchecked((int)0x80000001),
LocalMachine = unchecked((int)0x80000002),
Users = unchecked((int)0x80000003),
PerformanceData = unchecked((int)0x80000004),
CurrentConfig = unchecked((int)0x80000005),
}
public enum RegistryView
{
Default = 0, // 0x0000 operate on the default registry view
Registry64 = Win32Native.KEY_WOW64_64KEY, // 0x0100 operate on the 64-bit registry view
Registry32 = Win32Native.KEY_WOW64_32KEY, // 0x0200 operate on the 32-bit registry view
};
public enum RegistryKeyPermissionCheck
{
Default = 0,
ReadSubTree = 1,
ReadWriteSubTree = 2
}
public static class Win32Native
{
internal const String ADVAPI32 = "advapi32.dll";
internal const int KEY_WOW64_64KEY = 0x0100; //
internal const int KEY_WOW64_32KEY = 0x0200; //
internal const int ERROR_SUCCESS = 0x0;
internal const int READ_CONTROL = 0x00020000;
internal const int SYNCHRONIZE = 0x00100000;
internal const int STANDARD_RIGHTS_READ = READ_CONTROL;
internal const int STANDARD_RIGHTS_WRITE = READ_CONTROL;
internal const int KEY_QUERY_VALUE = 0x0001;
internal const int KEY_SET_VALUE = 0x0002;
internal const int KEY_CREATE_SUB_KEY = 0x0004;
internal const int KEY_ENUMERATE_SUB_KEYS = 0x0008;
internal const int KEY_NOTIFY = 0x0010;
internal const int KEY_CREATE_LINK = 0x0020;
internal const int KEY_READ = ((STANDARD_RIGHTS_READ |
KEY_QUERY_VALUE |
KEY_ENUMERATE_SUB_KEYS |
KEY_NOTIFY)
&
(~SYNCHRONIZE));
internal const int KEY_WRITE = ((STANDARD_RIGHTS_WRITE |
KEY_SET_VALUE |
KEY_CREATE_SUB_KEY)
&
(~SYNCHRONIZE));
internal const int ERROR_ACCESS_DENIED = 0x5;
internal const int ERROR_BAD_IMPERSONATION_LEVEL = 0x542;
[DllImport(ADVAPI32, CharSet = CharSet.Auto, BestFitMapping = false)]
internal static extern int RegOpenKeyEx(SafeRegistryHandle hKey, String lpSubKey,
int ulOptions, int samDesired, out SafeRegistryHandle hkResult);
[DllImport(ADVAPI32, CharSet = CharSet.Auto, BestFitMapping = false)]
internal static extern int RegQueryInfoKey(SafeRegistryHandle hKey, [Out]StringBuilder lpClass,
int[] lpcbClass, IntPtr lpReserved_MustBeZero, ref int lpcSubKeys,
int[] lpcbMaxSubKeyLen, int[] lpcbMaxClassLen,
ref int lpcValues, int[] lpcbMaxValueNameLen,
int[] lpcbMaxValueLen, int[] lpcbSecurityDescriptor,
int[] lpftLastWriteTime);
[DllImport(ADVAPI32, CharSet = CharSet.Auto, BestFitMapping = false)]
internal unsafe static extern int RegEnumKeyEx(SafeRegistryHandle hKey, int dwIndex,
char* lpName, ref int lpcbName, int[] lpReserved,
[Out]StringBuilder lpClass, int[] lpcbClass,
long[] lpftLastWriteTime);
internal const int ERROR_MORE_DATA = 0xEA;
internal const int REG_NONE = 0; // No value type
internal const int REG_DWORD_BIG_ENDIAN = 5; // 32-bit number
internal const int REG_BINARY = 3; // Free form binary
internal const int REG_QWORD = 11; // 64-bit number
internal const int REG_DWORD = 4; // 32-bit number
internal const int REG_SZ = 1; // Unicode nul terminated string
internal const int REG_EXPAND_SZ = 2; // Unicode nul terminated string
internal const int REG_MULTI_SZ = 7; // Multiple Unicode strings
internal const int REG_LINK = 6; // Symbolic Link (unicode)
[DllImport(ADVAPI32, CharSet = CharSet.Auto, BestFitMapping = false)]
internal static extern int RegQueryValueEx(SafeRegistryHandle hKey, String lpValueName,
int[] lpReserved, ref int lpType, [Out] byte[] lpData,
ref int lpcbData);
[DllImport(ADVAPI32, CharSet = CharSet.Auto, BestFitMapping = false)]
internal static extern int RegQueryValueEx(SafeRegistryHandle hKey, String lpValueName,
int[] lpReserved, ref int lpType, ref int lpData,
ref int lpcbData);
[DllImport(ADVAPI32, CharSet = CharSet.Auto, BestFitMapping = false)]
internal static extern int RegQueryValueEx(SafeRegistryHandle hKey, String lpValueName,
int[] lpReserved, ref int lpType, ref long lpData,
ref int lpcbData);
[DllImport(ADVAPI32, CharSet = CharSet.Auto, BestFitMapping = false)]
internal static extern int RegQueryValueEx(SafeRegistryHandle hKey, String lpValueName,
int[] lpReserved, ref int lpType, [Out] char[] lpData,
ref int lpcbData);
[DllImport(ADVAPI32, CharSet = CharSet.Auto, BestFitMapping = false)]
internal static extern int RegQueryValueEx(SafeRegistryHandle hKey, String lpValueName,
int[] lpReserved, ref int lpType, [Out]StringBuilder lpData,
ref int lpcbData);
}

Getting System.InvalidOperationException Image added to an ImageList must either derive from Image or be an Icon

I'm using following code to get the image using icon path. I think I'm doing all the error checks before returning image. So why this exception. Exception generated on adding received image to image List. Exception is generated on users machine so no way to debug.
private static Icon ExtractIcon(string file, int number, bool largeIcon)
{
IntPtr large;
IntPtr small;
ExtractIconEx(file, number, out large, out small, 1);
try
{
return Icon.FromHandle(largeIcon ? large : small);
}
catch
{
return null;
}
}
[DllImport("Shell32.dll", EntryPoint = "ExtractIconExW", CharSet = CharSet.Unicode, ExactSpelling = true,
CallingConvention = CallingConvention.StdCall)]
private static extern int ExtractIconEx(string sFile, int iIndex, out IntPtr piLargeVersion,
out IntPtr piSmallVersion, int amountIcons);
[DllImport("shell32.dll")]
private static extern IntPtr ExtractAssociatedIcon(IntPtr hInst, StringBuilder lpIconPath,
out ushort lpiIcon);
public static Image GetImage(string icon)
{
try
{
if (!string.IsNullOrEmpty(icon))
{
if (icon.Contains(","))
{
string[] split = icon.Split(new[] { ',' });
if (!string.IsNullOrEmpty(split[0]))
{
int index;
int.TryParse(split[1], out index);
Icon image =
ExtractIcon(Environment.ExpandEnvironmentVariables(split[0]).TrimMatchingQuotes('\"'),
index, true);
if (image != null)
return image.ToBitmap();
}
}
if (File.Exists(icon))
{
try
{
Icon image = Icon.ExtractAssociatedIcon(icon);
return image != null ? image.ToBitmap() : Resources.picture;
}
catch (ArgumentException)
{
var strB = new StringBuilder(icon);
ushort uicon;
IntPtr handle = ExtractAssociatedIcon(IntPtr.Zero, strB, out uicon);
return Icon.FromHandle(handle).ToBitmap();
}
}
}
return Resources.picture;
}
catch (Exception)
{
return Resources.picture;
}
}
private static string TrimMatchingQuotes(this string input, char quote)
{
if ((input.Length >= 2) &&
(input[0] == quote) && (input[input.Length - 1] == quote))
return input.Substring(1, input.Length - 2);
return input;
}

Eject USB device via C#

I was looking for a short way to eject USB-devices via C#-code, so I coded a little class myself, yet it simply doesn't work. Since there's no popup that says "Lock success!" I assume that the problem relies within the "LockVolume"-function, but I don't know where.
Does anybody see the mistake I made?
class USBEject
{
[DllImport("kernel32.dll", SetLastError = true, CharSet = CharSet.Auto)]
private static extern IntPtr CreateFile(
string lpFileName,
uint dwDesiredAccess,
uint dwShareMode,
IntPtr SecurityAttributes,
uint dwCreationDisposition,
uint dwFlagsAndAttributes,
IntPtr hTemplateFile
);
[DllImport("kernel32.dll", ExactSpelling = true, SetLastError = true, CharSet = CharSet.Auto)]
private static extern bool DeviceIoControl(
IntPtr hDevice,
uint dwIoControlCode,
IntPtr lpInBuffer,
uint nInBufferSize,
IntPtr lpOutBuffer,
uint nOutBufferSize,
out uint lpBytesReturned,
IntPtr lpOverlapped
);
[DllImport("kernel32.dll", ExactSpelling = true, SetLastError = true, CharSet = CharSet.Auto)]
private static extern bool DeviceIoControl(
IntPtr hDevice,
uint dwIoControlCode,
byte[] lpInBuffer,
uint nInBufferSize,
IntPtr lpOutBuffer,
uint nOutBufferSize,
out uint lpBytesReturned,
IntPtr lpOverlapped
);
[DllImport("kernel32.dll", SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
private static extern bool CloseHandle(IntPtr hObject);
private IntPtr handle = IntPtr.Zero;
const int GENERIC_READ = 0x80000000;
const int GENERIC_WRITE = 0x40000000;
const int FILE_SHARE_READ = 0x1;
const int FILE_SHARE_WRITE = 0x2;
const int FSCTL_LOCK_VOLUME = 0x00090018;
const int FSCTL_DISMOUNT_VOLUME = 0x00090020;
const int IOCTL_STORAGE_EJECT_MEDIA = 0x2D4808;
const int IOCTL_STORAGE_MEDIA_REMOVAL = 0x002D4804;
/// <summary>
/// Constructor for the USBEject class
/// </summary>
/// <param name="driveLetter">This should be the drive letter. Format: F:/, C:/..</param>
public USBEject(string driveLetter)
{
string filename = #"\\.\" + driveLetter[0] + ":";
handle = CreateFile(filename, GENERIC_READ | GENERIC_WRITE, FILE_SHARE_READ | FILE_SHARE_WRITE, IntPtr.Zero, 0x3, 0, IntPtr.Zero);
}
public bool Eject()
{
if (LockVolume(handle) && DismountVolume(handle))
{
PreventRemovalOfVolume(handle, false);
return AutoEjectVolume(handle);
}
return false;
}
private bool LockVolume(IntPtr handle)
{
uint byteReturned;
for (int i = 0; i < 10; i++)
{
if (DeviceIoControl(handle, FSCTL_LOCK_VOLUME, IntPtr.Zero, 0, IntPtr.Zero, 0, out byteReturned, IntPtr.Zero))
{
System.Windows.Forms.MessageBox.Show("Lock success!");
return true;
}
Thread.Sleep(500);
}
return false;
}
private bool PreventRemovalOfVolume(IntPtr handle, bool prevent)
{
byte[] buf = new byte[1];
uint retVal;
buf[0] = (prevent) ? (byte)1 : (byte)0;
return DeviceIoControl(handle, IOCTL_STORAGE_MEDIA_REMOVAL, buf, 1, IntPtr.Zero, 0, out retVal, IntPtr.Zero);
}
private bool DismountVolume(IntPtr handle)
{
uint byteReturned;
return DeviceIoControl(handle, FSCTL_DISMOUNT_VOLUME, IntPtr.Zero, 0, IntPtr.Zero, 0, out byteReturned, IntPtr.Zero);
}
private bool AutoEjectVolume(IntPtr handle)
{
uint byteReturned;
return DeviceIoControl(handle, IOCTL_STORAGE_EJECT_MEDIA, IntPtr.Zero, 0, IntPtr.Zero, 0, out byteReturned, IntPtr.Zero);
}
private bool CloseVolume(IntPtr handle)
{
return CloseHandle(handle);
}
}

Changed just a little bit your code and it goes as follows:
[DllImport("kernel32.dll", SetLastError = true, CharSet = CharSet.Auto)]
private static extern IntPtr CreateFile(
string lpFileName,
uint dwDesiredAccess,
uint dwShareMode,
IntPtr SecurityAttributes,
uint dwCreationDisposition,
uint dwFlagsAndAttributes,
IntPtr hTemplateFile
);
[DllImport("kernel32.dll", ExactSpelling = true, SetLastError = true, CharSet = CharSet.Auto)]
private static extern bool DeviceIoControl(
IntPtr hDevice,
uint dwIoControlCode,
IntPtr lpInBuffer,
uint nInBufferSize,
IntPtr lpOutBuffer,
uint nOutBufferSize,
out uint lpBytesReturned,
IntPtr lpOverlapped
);
[DllImport("kernel32.dll", ExactSpelling = true, SetLastError = true, CharSet = CharSet.Auto)]
private static extern bool DeviceIoControl(
IntPtr hDevice,
uint dwIoControlCode,
byte[] lpInBuffer,
uint nInBufferSize,
IntPtr lpOutBuffer,
uint nOutBufferSize,
out uint lpBytesReturned,
IntPtr lpOverlapped
);
[DllImport("kernel32.dll", SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
private static extern bool CloseHandle(IntPtr hObject);
private IntPtr handle = IntPtr.Zero;
const uint GENERIC_READ = 0x80000000;
const uint GENERIC_WRITE = 0x40000000;
const int FILE_SHARE_READ = 0x1;
const int FILE_SHARE_WRITE = 0x2;
const int FSCTL_LOCK_VOLUME = 0x00090018;
const int FSCTL_DISMOUNT_VOLUME = 0x00090020;
const int IOCTL_STORAGE_EJECT_MEDIA = 0x2D4808;
const int IOCTL_STORAGE_MEDIA_REMOVAL = 0x002D4804;
/// <summary>
/// Constructor for the USBEject class
/// </summary>
/// <param name="driveLetter">This should be the drive letter. Format: F:/, C:/..</param>
public IntPtr USBEject(string driveLetter)
{
string filename = #"\\.\" + driveLetter[0] + ":";
return CreateFile(filename, GENERIC_READ | GENERIC_WRITE, FILE_SHARE_READ | FILE_SHARE_WRITE, IntPtr.Zero, 0x3, 0, IntPtr.Zero);
}
public bool Eject(IntPtr handle)
{
bool result = false;
if (LockVolume(handle) && DismountVolume(handle))
{
PreventRemovalOfVolume(handle, false);
result = AutoEjectVolume(handle);
}
CloseHandle(handle);
return result;
}
private bool LockVolume(IntPtr handle)
{
uint byteReturned;
for (int i = 0; i < 10; i++)
{
if (DeviceIoControl(handle, FSCTL_LOCK_VOLUME, IntPtr.Zero, 0, IntPtr.Zero, 0, out byteReturned, IntPtr.Zero))
{
System.Windows.Forms.MessageBox.Show("Lock success!");
return true;
}
Thread.Sleep(500);
}
return false;
}
private bool PreventRemovalOfVolume(IntPtr handle, bool prevent)
{
byte[] buf = new byte[1];
uint retVal;
buf[0] = (prevent) ? (byte)1 : (byte)0;
return DeviceIoControl(handle, IOCTL_STORAGE_MEDIA_REMOVAL, buf, 1, IntPtr.Zero, 0, out retVal, IntPtr.Zero);
}
private bool DismountVolume(IntPtr handle)
{
uint byteReturned;
return DeviceIoControl(handle, FSCTL_DISMOUNT_VOLUME, IntPtr.Zero, 0, IntPtr.Zero, 0, out byteReturned, IntPtr.Zero);
}
private bool AutoEjectVolume(IntPtr handle)
{
uint byteReturned;
return DeviceIoControl(handle, IOCTL_STORAGE_EJECT_MEDIA, IntPtr.Zero, 0, IntPtr.Zero, 0, out byteReturned, IntPtr.Zero);
}
private bool CloseVolume(IntPtr handle)
{
return CloseHandle(handle);
}
So you can use it in two ways:
handle = USBEject("D:");
Eject(handle);
or directly:
Eject(USBEject("D:"));
It works for me on my Windows 10 machine (preview 14291)

Found the answer for my issue by using some of Roger Deep's code for the CreateFile call.
My code to remove a USB drive inside WPF Window:
private void Button_Click_1(object sender, RoutedEventArgs e)
{
EjectDrive('K');
}
void EjectDrive(char driveLetter)
{
string path = #"\\.\" + driveLetter + #":";
IntPtr handle = CreateFile(path, GENERIC_READ | GENERIC_WRITE,
FILE_SHARE_READ | FILE_SHARE_WRITE, IntPtr.Zero, 0x3, 0, IntPtr.Zero);
if ((long)handle == -1)
{
MessageBox.Show("Unable to open drive " + driveLetter);
return;
}
int dummy = 0;
DeviceIoControl(handle, IOCTL_STORAGE_EJECT_MEDIA, IntPtr.Zero, 0,
IntPtr.Zero, 0, ref dummy, IntPtr.Zero);
CloseHandle(handle);
MessageBox.Show("OK to remove drive.");
}
[DllImport("kernel32", SetLastError = true)]
private static extern IntPtr CreateFile
(string filename, uint desiredAccess,
uint shareMode, IntPtr securityAttributes,
int creationDisposition, int flagsAndAttributes,
IntPtr templateFile);
[DllImport("kernel32")]
private static extern int DeviceIoControl
(IntPtr deviceHandle, uint ioControlCode,
IntPtr inBuffer, int inBufferSize,
IntPtr outBuffer, int outBufferSize,
ref int bytesReturned, IntPtr overlapped);
[DllImport("kernel32.dll", SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
private static extern bool CloseHandle(IntPtr hObject);

Here's some code that I converted from a powershell script. You need to run with admin privileges and It works to "unmount" the USB drive. However, when you try to unplug the USB drive and plug it in again, it doesn't show up as a drive letter. (To get around that you need to type "WindowsKey-X" and select Disk-Manager to reassign the drive less to the USB device. (If anybody knows how to fix that problem please post to commits.) Here's the Code:
// Right click Project and Add Reference to System.Management.dll
using System.Management;
string mq = "SELECT * FROM Win32_Volume Where Name = 'E:\\'";
ManagementObjectSearcher ms = new ManagementObjectSearcher(mq);
foreach (ManagementObject mo in ms.Get())
{
mo["DriveLetter"] = null;
mo.Put();
ManagementBaseObject inParams = mo.GetMethodParameters("Dismount");
inParams["Force"] = false;
inParams["Permanent"] = false;
mo.InvokeMethod("Dismount", inParams, null);
}
Note that the powershell script also has the same problem of reattaching the USB device after ejecting. Here's the powershell script for your reference:
$vol = get-wmiobject -Class Win32_Volume |
where{$_.Name -eq 'E:\'}
$vol.DriveLetter = $null
$vol.Put()
$vol.Dismount($false, $false)
Here's a class that I just wrote to Manage Mounting and Unmounting of Removable USB Drives using WMI:
using System;
using System.IO;
using System.Text;
using System.Windows;
using System.Management; //<-- right-click on project and add reference
using System.Collections.Generic;
using System.Text.RegularExpressions;
// This Class implements Mount/Unmount for USB Removable Drives
// in a way similar to "Disk Manager" in the Control Panel.
//
// Currently, It doesn't implement "Eject" like when you right
// right-click on the USB icon on lower right of screen.
// The "Unmount" is similar to "Eject" except it dosn't
// cleanup the registry so that the USB drive can be automatically
// recognized again without manually mounting it from "Disk Manager"
// If somebody knows how to fix this class to gain this function...
// please post it to their thread. Thanks.
namespace WPM {
public struct UsbDriveItem_t {
public int Index;
public string DeviceId;
public char DriveLetter;
public string Label;
public override string ToString() {
if (Index < 0)
return "<none>";
else
return String.Format("{0}: {1}", DriveLetter, Label);
}
};
delegate void UsbEvent();
class UsbDriveRemovable {
public static int Unmount(char DriveLetter) {
bool success = ValidateAdmin("UsbDriveRemovable.Unmount()");
if (!success) return -1;
string Name = "'" + DriveLetter + ":\\\\'";
string mq = "SELECT * FROM Win32_Volume Where Name = " + Name;
ManagementObjectSearcher ms = new ManagementObjectSearcher(mq);
ManagementObjectCollection mc = ms.Get();
foreach (ManagementObject mo in mc) {
var DriveLetterI = mo["DriveLetter"].ToString();
mo["DriveLetter"] = null;
mo.Put();
ManagementBaseObject inParams = mo.GetMethodParameters("Dismount");
inParams["Force"] = false;
inParams["Permanent"] = false;
ManagementBaseObject outParams = mo.InvokeMethod("Dismount", inParams, null);
string rc = outParams["ReturnValue"].ToString();
mo.Dispose();
}
mc.Dispose();
ms.Dispose();
return 0;
}
public static int Mount(string DeviceId, char Letter = '?') {
bool success = ValidateAdmin("UsbDriveRemovable.Mount()");
if (!success) return -1;
if (Letter == '?' || Letter == '#') {
GetFirstUnsedLetter(out Letter);
}
string FixDeviceId = Regex.Replace(DeviceId, #"\\", #"\\");
string mq = "SELECT * FROM Win32_Volume WHERE DeviceId = '"
+ FixDeviceId
+ "'";
ManagementObjectSearcher ms = new ManagementObjectSearcher(mq);
ManagementObjectCollection mc = ms.Get();
foreach (ManagementObject mo in mc) {
ManagementBaseObject inParams = mo.GetMethodParameters("AddMountPoint");
inParams["Directory"] = Letter + ":\\";
ManagementBaseObject outParams = mo.InvokeMethod("AddMountPoint", inParams, null);
string rc = outParams["ReturnValue"].ToString();
mo.Dispose();
}
mc.Dispose();
ms.Dispose();
return 0;
}
/*List<UsbDriveItem_t>*/
public static int ListDrives(ref List<UsbDriveItem_t> DriveList) {
DriveList.Clear();
string mq = "SELECT * FROM Win32_Volume Where DriveType = '2'";
ManagementObjectSearcher ms = new ManagementObjectSearcher(mq);
ManagementObjectCollection mc = ms.Get();
int count = 0;
foreach (ManagementObject mo in mc) {
UsbDriveItem_t item = new UsbDriveItem_t();
item.Index = count;
item.Label = (mo["Label"] == null) ? "<none>" : mo["Label"].ToString();
item.DriveLetter = (mo["DriveLetter"] == null) ? '#' : mo["DriveLetter"].ToString()[0];
item.DeviceId = (mo["DeviceId"] == null) ? "<none>" : mo["DeviceId"].ToString();
DriveList.Add(item);
mo.Dispose();
}
count++;
mc.Dispose();
ms.Dispose();
return 0;
}
public static void MountItem(UsbDriveItem_t DriveItem) {
char DriveLetter = DriveItem.DriveLetter;
string DriveLabel = DriveItem.Label;
string DeviceId = DriveItem.DeviceId;
// Mount Drive if its not already Mounted
if (DriveLetter == '#') {
UsbDriveRemovable.GetFirstUnsedLetter(out DriveLetter);
UsbDriveRemovable.Mount(DeviceId, DriveLetter);
}
return;
}
public static void UnmountItem(UsbDriveItem_t DriveItem) {
char DriveLetter = DriveItem.DriveLetter;
UsbDriveRemovable.Unmount(DriveLetter);
return;
}
public static int GetFirstUnsedLetter(out char Letter) {
bool[] alphabet = new bool[26];
for (int i=0; i < 26; i++) {
alphabet[i] = false;
}
string mq = "SELECT * FROM Win32_Volume";
ManagementObjectSearcher ms = new ManagementObjectSearcher(mq);
ManagementObjectCollection mc = ms.Get();
foreach (ManagementObject mo in mc) {
if (mo["DriveLetter"] != null) {
char cc = mo["DriveLetter"].ToString()[0];
int ci = char.ToUpper(cc) - 65;
alphabet[ci] = true;
}
mo.Dispose();
}
mc.Dispose();
ms.Dispose();
int found = -1;
for (int i=3; i < 26; i++) {
if (alphabet[i] == false) {
found = i;
break;
}
}
if (found >= 0) {
Letter = (char)(found + 65);
return 0;
}
else {
Letter = '?';
return -1;
}
}
public static object
RegisterInsertEvent(UsbEvent InsertEvent) {
var insertQuery = new WqlEventQuery("SELECT * FROM Win32_DeviceChangeEvent WHERE EventType = 2");
var insertWatcher = new ManagementEventWatcher(insertQuery);
insertWatcher.EventArrived += delegate(object sender, EventArrivedEventArgs e) {
// string driveName = e.NewEvent.Properties["DriveName"].Value.ToString();
Action action = delegate {
InsertEvent();
};
Application.Current.Dispatcher.BeginInvoke(action);
};
insertWatcher.Start();
return (object)insertWatcher;
}
public static object RegisterRemoveEvent(UsbEvent RemoveEvent) {
var removeQuery = new WqlEventQuery("SELECT * FROM Win32_DeviceChangeEvent WHERE EventType = 3");
var removeWatcher = new ManagementEventWatcher(removeQuery);
removeWatcher.EventArrived += delegate(object sender, EventArrivedEventArgs e) {
// string driveName = e.NewEvent.Properties["DriveName"].Value.ToString();
Action action = delegate {
RemoveEvent();
};
Application.Current.Dispatcher.BeginInvoke(action);
};
removeWatcher.Start();
return (object)removeWatcher;
}
// Mount all UsbRemovable Drives that are not currently mounted
public static int MountAll() {
List<UsbDriveItem_t> DriveList = new List<UsbDriveItem_t>();
ListDrives(ref DriveList);
foreach (UsbDriveItem_t item in DriveList) {
if (item.DriveLetter == '?') {
Mount(item.DeviceId);
}
}
return 0;
}
// Unmount all UsbRemovable Drives
public static int UnmountAll() {
List<UsbDriveItem_t> DriveList = new List<UsbDriveItem_t>();
ListDrives(ref DriveList);
foreach (UsbDriveItem_t item in DriveList) {
if (item.DriveLetter != '?') {
Unmount(item.DriveLetter);
}
}
return 0;
}
public static bool IsAdministrator()
{
var id = System.Security.Principal.WindowsIdentity.GetCurrent();
var prin = new System.Security.Principal.WindowsPrincipal(id);
return prin.IsInRole(
System.Security.Principal.WindowsBuiltInRole.Administrator);
}
public static bool ValidateAdmin(string CalledFrom = null) {
if (CalledFrom == null) {
CalledFrom = "";
}
if (!IsAdministrator()) {
string msg = "Please rerun this application with admin privileges.\r\n\r\n"
+ "Access denied to call " + CalledFrom + "\r\n\r\n";
MessageBox.Show(msg, "ERROR");
return false;
}
return true;
}
public static void StartExplorer(char DriveLetter)
{
var proc1 = new System.Diagnostics.Process();
proc1.StartInfo.FileName = #"C:\\Windows\\System32\\explorer.exe";
proc1.StartInfo.Arguments = DriveLetter.ToString();
proc1.StartInfo.CreateNoWindow = true;
proc1.StartInfo.UseShellExecute = false;
proc1.StartInfo.RedirectStandardOutput = true;
proc1.StartInfo.RedirectStandardError = true;
proc1.Start();
proc1.WaitForExit();
string proc1out = proc1.StandardOutput.ReadToEnd();
string proc1err = proc1.StandardError.ReadToEnd();
//if (proc1.ExitCode != 0) {
// string msg = proc1out + "\r\n\r\n" + proc1err;
// MessageBox.Show(msg, "Error: Mountvol /R");
//}
proc1.Close();
}
} //class
} //namespace
/* DOESN'T WORK WELL...
// Kludge to get USB Drive to be recognized again
void UsbCleanup() {
var proc1 = new System.Diagnostics.Process();
proc1.StartInfo.FileName = #"C:\\Windows\\System32\\mountvol.exe";
proc1.StartInfo.Arguments = #"/R";
proc1.StartInfo.CreateNoWindow = true;
proc1.StartInfo.UseShellExecute = false;
proc1.StartInfo.RedirectStandardOutput = true;
proc1.StartInfo.RedirectStandardError = true;
proc1.Start();
proc1.WaitForExit();
string proc1out = proc1.StandardOutput.ReadToEnd();
string proc1err = proc1.StandardError.ReadToEnd();
if (proc1.ExitCode != 0) {
string msg = proc1out + "\r\n\r\n" + proc1err;
MessageBox.Show(msg, "Error: Mountvol /R");
}
proc1.Close();
var proc2 = new System.Diagnostics.Process();
proc2.StartInfo.FileName = #"C:\\Windows\\System32\\mountvol.exe";
proc2.StartInfo.Arguments = #"/E";
proc2.StartInfo.CreateNoWindow = true;
proc2.StartInfo.UseShellExecute = false;
proc2.StartInfo.RedirectStandardOutput = true;
proc2.StartInfo.RedirectStandardError = true;
proc2.Start();
proc2.WaitForExit();
string proc2out = proc2.StandardOutput.ReadToEnd();
string proc2err = proc2.StandardError.ReadToEnd();
if (proc2.ExitCode != 0) {
string msg = proc1out + "\r\n\r\n" + proc1err;
MessageBox.Show(msg, "Error: Mountvol /E");
}
proc2.Close();
return;
}
*/

You could convert the following PowerShell into C#:
$Eject = New-Object -comObject Shell.Application
$Eject.NameSpace(17).ParseName($usbDrvLetter+“:”).InvokeVerb(“Eject”)

What is wrong with this pinvoke?

I have this piece of code that has not been modified but all of a sudden it has stopped working... I could swear that it used to work but can't guarantee it. It throws an exception:
Attempted to read or write protected memory. This is often an indication that other memory is corrupt.
static void Main(string[] args)
{
ErrorMsg(123);
}
[DllImport("kernel32.dll", EntryPoint = "FormatMessageW", CharSet = CharSet.Auto)]
static extern int FormatMessage(int dwFlags, IntPtr lpSource, long dwMessageId, int dwLanguageId, out IntPtr MsgBuffer, int nSize, IntPtr Arguments);
[DllImport("kernel32.dll", CharSet = CharSet.Auto)]
public static extern int GetThreadLocale();
/// <summary>
/// Gets a Locale specific windows error
/// code specified.
/// </summary>
/// <param name="errorcode">The errorcode.</param>
public static string ErrorMsg(long errorcode)
{
try
{
if (errorcode == 0)
return "No Error";
IntPtr pMessageBuffer;
int dwBufferLength;
string sMsg;
int dwFormatFlags;
//FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS
dwFormatFlags = 0x00000100 | 0x00000200 | 0x00001000;
dwBufferLength = FormatMessage(dwFormatFlags, IntPtr.Zero, errorcode, GetThreadLocale(), out pMessageBuffer, 0, IntPtr.Zero);
if (dwBufferLength == 0)
return "An Unknown Error Has occured.";
sMsg = Marshal.PtrToStringUni(pMessageBuffer);
Marshal.FreeHGlobal(pMessageBuffer);
return sMsg;
}
catch (Exception ex)
{
return "An Unknown Error Has occured.";
}
}
What am I doing wrong here, I can't seem to find anything? Thanks!

Your code worked fine when I tested it on my machine. By the way is there any reason you wouldn't prefer the following method which is a little shorter and achieves equivalent goal:
static void Main()
{
var ex = new Win32Exception(123);
Console.WriteLine(ex.Message);
}
Of course under the covers Win32Exception PInvokes into FormatMessage but at least it's the .NET framework that should worry about it, not us.
UPDATE:
Here's how the Win32Exception.GetErrorMessage method is implemented in .NET:
private static string GetErrorMessage(int error)
{
string result = "";
StringBuilder stringBuilder = new StringBuilder(256);
int num = SafeNativeMethods.FormatMessage(12800, NativeMethods.NullHandleRef, error, 0, stringBuilder, stringBuilder.Capacity + 1, IntPtr.Zero);
if (num != 0)
{
int i;
for (i = stringBuilder.Length; i > 0; i--)
{
char c = stringBuilder[i - 1];
if (c > ' ' && c != '.')
{
break;
}
}
result = stringBuilder.ToString(0, i);
}
else
{
result = "Unknown error (0x" + Convert.ToString(error, 16) + ")";
}
return result;
}
where FormatMessage is declared like this:
[DllImport("kernel32.dll", BestFitMapping = true, CharSet = CharSet.Auto, SetLastError = true)]
public static extern int FormatMessage(int dwFlags, HandleRef lpSource, int dwMessageId, int dwLanguageId, StringBuilder lpBuffer, int nSize, IntPtr arguments);

Try sMsg = Marshal.PtrToStringUni(pMessageBuffer, dwBufferLength);