Question : detect registry change windows ce

Hi, I need to detect when registry values change on Windows CE using vb.net.

Answer : detect registry change windows ce

I had some time to play with the functions. I used the emulator and it works fine on that ;)... Example also located on MSDN @ CeFindFirstRegChange()
1:
2:
3:
4:
5:
6:
7:
8:
9:
10:
11:
12:
13:
14:
15:
16:
17:
18:
19:
20:
21:
22:
23:
24:
25:
26:
27:
28:
29:
30:
31:
32:
33:
34:
35:
36:
37:
38:
39:
40:
41:
42:
43:
44:
45:
46:
47:
48:
49:
50:
51:
52:
53:
54:
55:
56:
57:
58:
59:
60:
61:
62:
63:
64:
65:
66:
67:
68:
69:
70:
71:
72:
73:
74:
75:
76:
77:
78:
79:
80:
81:
82:
83:
84:
85:
86:
87:
88:
89:
90:
91:
92:
93:
94:
95:
96:
97:
98:
99:
100:
101:
102:
103:
104:
105:
106:
107:
108:
109:
110:
111:
112:
113:
114:
115:
116:
117:
118:
119:
120:
121:
122:
123:



Imports System
Imports System.Threading
Imports System.Runtime.InteropServices
Imports Microsoft.Win32

Public Class RegistryNotification
    ' egl1044

    ' Constructor
    Public Sub New()

    End Sub

    <Flags()> _
    Public Enum RegNotifyFilter
        REG_NOTIFY_CHANGE_NAME = 1 'Notify the caller if a subkey is added or deleted.
        REG_NOTIFY_CHANGE_LAST_SET = 4 'Notify the caller of changes to a value of the key. This can include adding or deleting a value or changing an existing value.
    End Enum

    Public Enum RegType
        HKEY_LOCAL_MACHINE = &H80000002
        HKEY_CLASSES_ROOT = &H80000000
        HKEY_CURRENT_USER = &H80000001
        HKEY_USERS = &H80000003
    End Enum

    ' Not implemented in this example.
    '<StructLayout(LayoutKind.Sequential, CharSet:=CharSet.Unicode)> _
    'Private Structure REG_NOTIFY_INFORMATION
    '    Dim NextEntryOffset As Integer
    '    Dim Action As Integer
    '    Dim RegNameLength As Integer
    '    Dim RegName As IntPtr
    'End Structure

    <DllImport("coredll.dll", CharSet:=CharSet.Auto, SetLastError:=True)> _
    Private Shared Function CeFindCloseRegChange(ByVal hChangeHandle As IntPtr) As Integer
    End Function

    <DllImport("coredll.dll", CharSet:=CharSet.Auto, SetLastError:=True)> _
    Private Shared Function CeFindFirstRegChange(ByVal hKey As IntPtr, ByVal bWatchSubtree As Integer, ByVal dwNotifyFilter As RegNotifyFilter) As IntPtr
    End Function

    <DllImport("coredll.dll", CharSet:=CharSet.Auto, SetLastError:=True)> _
    Private Shared Function CeFindNextRegChange(ByVal hChangeHandle As IntPtr) As Integer
    End Function

    <DllImport("coredll.dll", CharSet:=CharSet.Auto, SetLastError:=True)> _
    Private Shared Function RegOpenKeyEx(ByVal hKey As RegType, ByVal lpSubKey As String, ByVal ulOptions As Integer, ByVal samDesired As Integer, ByRef phkResult As IntPtr) As Integer
    End Function

    <DllImport("coredll.dll", CharSet:=CharSet.Auto, SetLastError:=True)> _
    Private Shared Function RegCloseKey(ByVal hKey As IntPtr) As Integer
    End Function

    <DllImport("coredll.dll", SetLastError:=True)> _
    Private Shared Function WaitForSingleObject(ByVal handle As IntPtr, ByVal ms As Integer) As Integer
    End Function

    Private hKey As IntPtr = IntPtr.Zero '// registry handle
    Private hChangeHandle As IntPtr = IntPtr.Zero '// registry notification handle
    Private NotifyThread As Thread = Nothing
    Private bCancel As Boolean = False

    Public Sub StartRegistryWatcher()
        ' Watch for notifications on a seperate thread.
        bCancel = False
        NotifyThread = New Thread(AddressOf RegistryNotificationThread)
        NotifyThread.IsBackground = True
        NotifyThread.Start()
    End Sub

    Public Sub StopRegistryWatcher()
        ' Cancel notifications on the seperate thread.
        bCancel = True
        CeFindCloseRegChange(hChangeHandle)
    End Sub

    ' <(THREAD)>
    Private Sub RegistryNotificationThread()
        ' Run change notifications on new thread.
        RegisterRegistryChange(RegType.HKEY_LOCAL_MACHINE, "Software\fabrikan", 0)
    End Sub

    Private Sub RegisterRegistryChange(ByVal rootKey As RegType, ByVal keyName As String, ByVal watchSubTree As Integer)
        ' Detects registry notifications.
        If RegOpenKeyEx(rootKey, keyName, 0, 0, hKey) <> 0 Then
            MsgBox("RegOpenKeyEx failed.")
            Return
        End If
        ' TODO:// Change filter settings here
        hChangeHandle = CeFindFirstRegChange(hKey, watchSubTree, RegNotifyFilter.REG_NOTIFY_CHANGE_LAST_SET)
        If hChangeHandle.ToInt32 = -1 Then
            MsgBox("CeFindFirstRegChange failed")
            RegCloseKey(hKey)
            Return
        End If
        Do While bCancel <> True
            WaitForSingleObject(hChangeHandle, Timeout.Infinite)
            MsgBox("Change Detected!")
            CeFindNextRegChange(hChangeHandle)
            Thread.Sleep(0)
        Loop
        ' TODO://
        CeFindCloseRegChange(hChangeHandle)
        RegCloseKey(hKey)
    End Sub

    Public Sub DebugCreateRegistryEntry()
        ' Creates the specified key in the registry for debugging.
        Dim rk As RegistryKey = Registry.LocalMachine.OpenSubKey("Software", True)
        rk.CreateSubKey("fabrikan")
        rk.Close()
    End Sub

    Public Sub DebugChangeRegistryValue()
        ' Simulate a change in the registry for debugging.
        Dim rk As RegistryKey = Registry.LocalMachine.OpenSubKey("Software\fabrikan", True)
        rk.SetValue("fabrikans", TimeOfDay.Second.ToString, RegistryValueKind.String)
        rk.Close()
    End Sub

End Class