Public Shared Function SQLInstallerError(ByVal iError As Integer, ByRef pfErrorCode As Integer, ByVal lpszErrorMsg As StringBuilder, ByVal cbErrorMsgMax As Integer, ByRef pcbErrorMsg As Integer) As SQL_RETURN_CODE

Public Declare Auto Function mciGetErrorString Lib "winmm.dll" (ByVal errorCode As Integer, ByRef errorText As StringBuilder, ByVal errorTextSize As Integer) As Integer

Declare Ansi Function mciSendString Lib "winmm.dll" Alias "mciSendStringA" (ByVal command As String, ByRef buffer As StringBuilder, ByVal bufferSize As Integer, ByVal hWndCallback As IntPtr) As Integer

Protected Overrides Sub WndProc(ByRef m As System.Windows.Forms.Message)

Declare Function midiOutClose Lib "winmm.dll" (ByRef phMidiOut As IntPtr) As Uinteger

    <DllImport("winmm.dll")> Shared Function midiOutOpen(ByRef lphMidiOut As IntPtr, ByVal uDeviceID As UInteger, ByVal dwCallback As IntPtr, ByVal dwInstance As IntPtr, ByVal dwFlags As UInteger) As UInteger

Declare Function mixerGetControlDetails Lib "winmm.dll" (<MarshalAs(UnmanagedType.I4)> ByVal hmxobj As Integer, ByRef pmxcd As MIXERCONTROLDETAILS, ByVal fdwDetails As Integer) As Integer

   Private Shared Function MixerGetDevCaps(ByVal mixerId As Integer, ByRef mixerCaps As MixerCaps, ByVal mixerCapsSize As Integer) As UInteger

Shared Function mixerGetID(<MarshalAs(UnmanagedType.I4)> ByVal hmxobj As Integer, ByRef puMxId As UInteger, ByVal fdwId As MixerFlags) As MMRESULT

   ByRef pmxlc As MIXERLINECONTROLS, fdwControls As Integer) As Integer

Shared Function mixerGetLineInfo(<MarshalAs(UnmanagedType.I4)> ByVal hmxobj As Integer, ByRef pmxl As MIXERLINE, ByVal fdwInfo As MixerFlags) As MMRESULT

Declare Function mixerOpen Lib "winmm.dll" (ByRef phmx As IntPtr, ByVal pMxId As UInteger, ByVal dwCallback As IntPtr, ByVal dwInstance As IntPtr, ByVal fdwOpen As UInteger) As Integer

Declare Function timeGetDevCaps Lib "winmm.dll" (ByRef lpTimeCaps As TimeCaps, ByVal uSize As UInt32) As UInt32

Shared Function waveInAddBuffer(<MarshalAs(UnmanagedType.I4)> ByVal hwi As Integer, ByRef pwh As WAVEHDR, ByVal cbwh As UInteger) As MMRESULT

When recording waveform audio, usually buffers are allocated with unmanaged functions and kept in an IntPtr() array; for this reason the function is provided in two versions, one processing a WAVEHDR ByRef and the other working with an IntPtr.

Shared Function waveInUnprepareHeader(<MarshalAs(UnmanagedType.I4)> ByVal hwi As Integer, ByRef pwh As WAVEHDR, ByVal cbwh As UInteger) As MMRESULT

Declare Auto Function waveOutGetDevCaps Lib "winmm.dll" (ByVal uDeviceID as Integer, ByRef lpCaps As WAVEOUTCAPS, _

Declare Function waveOutGetVolume Lib "winmm.dll" (ByVal hwo As IntPtr, ByRef dwVolume As UInteger) As Integer

Declare Function waveOutOpen Lib "winmm.dll" Alias "waveOutOpen" (ByRef phwi As IntPtr, ByVal uDeviceID As IntPtr, ByRef pwfx As WAVEFORMATEX, ByVal dwCallback As IntPtr, ByVal dwCallbackInstance As IntPtr, ByVal fdwOpen As WAVE_FLAGS) As MMSYSERR

Declare Function waveOutOpen Lib "winmm.dll" Alias "waveOutOpen" (ByRef phwi As IntPtr, ByVal uDeviceID As IntPtr, ByRef pwfx As WAVEFORMATEXTENSIBLE, ByVal dwCallback As IntPtr, ByVal dwCallbackInstance As IntPtr, ByVal fdwOpen As WAVE_FLAGS) As MMSYSERR

    Public Shared Function CreateEnvironmentBlock(ByRef lpEnvironment As IntPtr, ByVal hToken As IntPtr, ByVal bInherit As Boolean) As Boolean

        Public Shared Function LoadUserProfile(ByVal hToken As IntPtr, ByRef lpProfileInfo As PROFILEINFO) As Boolean

Declare Function WNetAddConnection2 Lib "mpr.dll" (ByRef netResource As _

                           ByRef lpNetResource As NETRESOURCE, _

Public Shared Function WNetEnumResource(hEnum As IntPtr, ByRef lpcCount As Integer, lpBuffer As IntPtr, ByRef lpBufferSize As UInteger) As UInteger

    Public Function WNetEnumResource(ByVal hEnum As IntPtr, ByRef lpcCount As Integer, ByVal lpBuffer As IntPtr, ByRef lpBufferSize As Integer) As Integer

    Public Function WNetOpenEnum(ByVal dwScope As RESOURCE_SCOPE, ByVal dwType As RESOURCE_TYPE, ByVal dwUsage As RESOURCE_USAGE, ByRef lpNetResource As NETRESOURCE, ByRef lphEnum As IntPtr) As Integer

    Public Function GetNetworkDrives(ByRef o As NETRESOURCE, ByRef networkDriveCollection As List(Of String)) As Boolean

    Public Function GetNetworkComputers(ByRef o As NETRESOURCE, ByRef networkComputersCollection As List(Of String)) As Boolean

    Public Function WNETOE(ByRef o As NETRESOURCE, ByRef resourceCollection As List(Of String)) As Boolean

                      ByRef length As Integer) As Integer

    Declare Function WNetGetConnection Lib "mpr.dll" Alias "WNetGetConnectionA" (ByVal localName As String, ByVal remoteName As System.Text.StringBuilder, ByRef length As Integer) As Integer

    ByVal remoteName As System.Text.StringBuilder, ByRef length As Integer) As Integer

                      ByRef length As Integer) As Integer

Declare Function WNetGetLastError Lib "mpr.dll" Alias "WNetGetLastErrorA" (ByRef lpError As Integer, ByVal lpErrorBuf As String, ByVal nErrorBufSize As Integer, ByVal lpNameBuf As String, ByVal nNameBufSize As Integer) As Integer

Public Shared Function WNetOpenEnum(dwScope As ResourceScope, dwType As ResourceType, dwUsage As ResourceUsage, lpNetResource As NetResource, ByRef lphEnum As IntPtr) As UInteger

   ByRef rclsid As Guid, pvReserved As IntPtr, _

Declare Unicode Function LoadTypeLib Lib "oleaut32.dll" (ByVal szFile As String, ByRef TPpTypeLib As System.Runtime.InteropServices.ComTypes.ITypeLib) As Integer

    Private Shared Function OleCreatePictureIndirect(<MarshalAs(UnmanagedType.AsAny)>picdesc As Object, ByRef iid As Guid, <MarshalAs(UnmanagedType.Bool)>fOwn As Boolean) As stdole.IPictureDisp

Declare Function SysFreeString Lib "oleaut32.dll" (ByRef bstr as String) As Long

Declare Unicode Function UnRegisterTypeLib Lib "oleaut32.dll" (ByRef LibID As System.Guid, ByVal nVerMajor As Short, ByVal nVerMinor As Short, ByVal lCID As Integer, ByVal tSysKind As System.Runtime.InteropServices.ComTypes.SYSKIND) As Integer

    Private Declare Unicode Function LoadTypeLib Lib "oleaut32.dll" (ByVal TLpszModule As String, ByRef TPpTypeLib As ComTypes.ITypeLib2) As Integer

    Private Declare Unicode Function UnRegisterTypeLib Lib "oleaut32.dll" (ByRef LibID As System.Guid, ByVal nVerMajor As Short, ByVal nVerMinor As Short, ByVal lCID As Integer, ByVal tSysKind As ComTypes.SYSKIND) As Integer

Declare Function VarBstrFromDisp Lib "oleaut32.dll" (Byval Disp as IntPtr, Byval lcid As Integer, Byref pbstrOut as String) As Integer

If you write a COM interface which will be used by Javascript or Vbscript, you really need this function. Automation variables are very difficult to manage and they are passed by reference (VT_BYREF) or as Dispatch (VT_DISPATCH) or as a number while you just need, e.g. a string.

Declare Function WinHttpGetIEProxyConfigForCurrentUser Lib "winhttp.dll" (ByRef pProxyConfig As WINHTTP_CURRENT_USER_IE_PROXY_CONFIG) As Boolean

Declare Function WinHttpOpenRequest Lib "winhttp.dll" (ByVal hConnect As IntPtr, ByVal pwszVerb As String, ByVal pwszObjectName As String, ByVal pwszVersion As String, ByVal pwszReferrer As String, ByRef ppwszAcceptTypes As Byte(), ByVal dwFlags As Integer) As IntPtr

Declare Function WinHttpOpenRequest Lib "winhttp.dll" (ByVal hConnect As IntPtr, ByVal pwszVerb As String, ByVal pwszObjectName As String, ByVal pwszVersion As String, ByVal pwszReferrer As String, ByRef ppwszAcceptTypes As Byte(), ByVal dwFlags As Integer) As IntPtr

Declare Function WinHttpQueryDataAvailable Lib "winhttp.dll" (ByVal hRequest As IntPtr, ByRef lpdwNumberOfBytesAvailable As Integer) As Boolean

Declare Function WinHttpQueryHeaders Lib "winhttp.dll" (ByVal hRequest As IntPtr, ByVal dwInfoLevel As Integer, ByVal pwszName As String, ByVal buffer As Byte(), ByRef lpdwBufferLength As Integer, ByRef lpdwIndex As Integer) As Boolean

Declare Function WinHttpQueryOption Lib "winhttp.dll" (ByVal hInternet As IntPtr, ByVal dwOption As Integer, ByVal lpBuffer As Byte(), ByRef lpdwBufferLength As Integer) As Boolean

Declare Function WinHttpReadData Lib "winhttp.dll" (ByVal hRequest As IntPtr, ByVal lpBuffer As Byte(), ByVal dwNumberOfBytesToRead As Integer, ByRef lpdwNumberOfBytesRead As Integer) As Boolean

Declare Function WinHttpWriteData Lib "winhttp.dll" (ByVal hRequest As IntPtr, ByVal lpBuffer As IntPtr, ByVal dwNumberOfBytesToWrite As UInteger, ByRef lpdwNumberOfBytesWritten As UInteger) As Boolean

    <Out> ByRef perceivedType As PerceivedType, _

    <Out> ByRef perceivedFlags As PerceivedFlags, _

Private Shared Function AssocQueryString(ByVal flags As UInteger, ByVal str As UInteger, ByVal pszAssoc As String, ByVal pszExtra As String, ByVal pszOut As Text.StringBuilder, ByRef pcchOut As UInteger) As UInteger

Private Shared Sub ColorRGBToHLS(RGB As Integer, ByRef H As Integer, ByRef L As Integer, ByRef S As Integer)

     ByRef pathLength As System.UInt32, _

     ByRef urlLength As System.UInt32, _

    ByRef pNumArgs As Integer) As Long

      ByRef index As Short) As IntPtr

            ByRef phiconLarge() As IntPtr, _

            ByRef phiconSmall() As IntPtr, _

         ByRef phiconLarge As Integer, _

         ByRef phiconSmall As Integer, _

Private Shared Function FindExecutable(ByVal lpFile As String, ByVal lpDirectory As String, ByRef lpResult As StringBuilder) As IntPtr

Declare Unicode Function PickIconDlg Lib "Shell32" Alias "PickIconDlg" (ByVal hwndOwner As IntPtr, ByVal lpstrFile As String, ByVal nMaxFile As Integer, ByRef lpdwIconIndex As Integer) As Integer

  Shared Function SHAppBarMessage(ByVal dwMessage As Integer, ByRef pData As APPBARDATA) As Integer

    Shared Function SHAppBarMessage(ByVal dwMessage As Integer, ByRef pData As APPBARDATA) As Integer

    Friend Sub New(ByRef DockForm As System.Windows.Forms.Form, ByVal dockStyle As AppBarDockStyle, ByVal AppBarSize As Size)

    Friend Sub RegisterBar(ByVal hWnd As IntPtr, ByRef uCallbackMessage As Int32, ByVal idealSize As Size, ByVal DockEdge As ABEdge)

    Friend Function GetWinTaskbarState(ByRef WinTaskBar As TaskbarState) As Boolean

    ByRef riid As Guid, _

    ByRef ppv As IntPtr, _

    ByRef pidlLast As IntPtr) As Integer

    ByRef ppv As IntPtr, _

    ByRef ppidlLast As IntPtr) As Integer

Public Shared Function SHBrowseForFolder(<MarshalAs(UnmanagedType.Struct)>ByRef lpFileOp As BROWSEINFO) As IntPtr

         <MarshalAs(UnmanagedType.Interface, IidParameterIndex:=2)> ByRef ppv As IShellItem)

Public Function ShellExecuteEx(ByRef lpExecInfo As SHELLEXECUTEINFO) As Boolean

    Public Shared Function ShellExecuteEx(ByRef lpExecInfo As SHELLEXECUTEINFO) As Boolean

Shared Function Shell_NotifyIcon(dwMessage as UInteger, ByRef pnid as NOTIFYICONDATA) as Boolean

Public Function SHFileOperation(<MarshalAs(UnmanagedType.Struct)>ByRef lpFileOp As SHFILEOPSTRUCT) As Integer

  Function SHGetDesktopFolder(ByRef ppshf As IShellFolder) As Integer

      ByRef psfi As SHFILEINFO, _

Declare Function SHGetImageList Lib "shell32.dll" (ByVal iImageList As Long, ByRef riid As Long, ByRef ppv As Any) As Long

Declare Function SHGetImageListXP Lib "shell32.dll" Alias "#727" (ByVal iImageList As Long, ByRef riid As Long, ByRef ppv As Any) As Long