C# Signature:

[DllImport("kernel32.dll", SetLastError = true)]
static extern IntPtr MapViewOfFile(IntPtr hFileMappingObject, uint
   dwDesiredAccess, uint dwFileOffsetHigh, uint dwFileOffsetLow,
   uint dwNumberOfBytesToMap);

VB .Net

Declare Function MapViewOfFile Lib "kernel32" (ByVal hFileMappingObject As IntPtr, ByVal dwDesiredAccess As UInt32, ByVal dwFileOffsetHigh As UInt32, ByVal dwFileOffsetLow As UInt32, ByVal dwNumberOfBytesToMap As UInt32) As UInt32

VB .Net Sample Code:

Declare Function MapViewOfFile Lib "kernel32" (ByVal hFileMappingObject As IntPtr, ByVal dwDesiredAccess As UInt32, ByVal dwFileOffsetHigh As UInt32, ByVal dwFileOffsetLow As UInt32, ByVal dwNumberOfBytesToMap As UInt32) As UInt32

Public Structure SECURITY_ATTRIBUTES
     Public lLength As Long
     Public lSecurityDescriptor As Long
     Public lInhertitHandle As Long
End Structure

Dim SecAttrib As SECURITY_ATTRIBUTES
Dim nAckEvent As Integer
Dim nReadyEvent As Integer
Dim nSharedFile As Long
Dim nSharedMem As Long
Dim nSecurityDesc As Integer

Public Const GPTR As Long = &H40
Public Const SECURITY_DESCRIPTOR_REVISION As Long = (1)
Public Const SECURITY_DESCRIPTOR_MIN_LENGTH As Long = (20)
Public Const PAGE_READWRITE As Int32 = &H4
Public Const FILE_MAP_READ As Int32 = &H40&, 512)

nSecurityDesc = GlobalAlloc(GPTR, SECURITY_DESCRIPTOR_MIN_LENGTH)

SecAttrib.lLength = SecAttrib.nLength
SecAttrib.lInheritHandle = Convert.ToInt32(True)
SecAttrib.lSecurityDescriptor = pSecurityDesc

nAckEvent = CreateEvent(SecAttrib, 0, 0, "DBWIN_BUFFER_READY")
nReadyEvent = CreateEvent(SecAttrib, 0, 0, "DBWIN_DATA_READY")
nSharedFile = CreateFileMapping(-1, SecAttrib, PAGE_READWRITE, 0&, 4096, "DBWIN_BUFFER")
nSharedMem = MapViewOfFile(nSharedFile, FILE_MAP_READ, 0&,  0&, 0&, 512)

User-Defined Types:

None.

Notes:

None.

Tips & Tricks:

Please add some!

C# Sample Code:

        const UInt32 STANDARD_RIGHTS_REQUIRED = 0x000F0000;
        const UInt32 SECTION_QUERY = 0x0001;
        const UInt32 SECTION_MAP_WRITE = 0x0002;
        const UInt32 SECTION_MAP_READ = 0x0004;
        const UInt32 SECTION_MAP_EXECUTE = 0x0008;
        const UInt32 SECTION_EXTEND_SIZE = 0x0010;
        const UInt32 SECTION_ALL_ACCESS = (STANDARD_RIGHTS_REQUIRED|SECTION_QUERY|
            SECTION_MAP_WRITE |      
            SECTION_MAP_READ |      
            SECTION_MAP_EXECUTE |    
            SECTION_EXTEND_SIZE);
        const UInt32 FILE_MAP_ALL_ACCESS = SECTION_ALL_ACCESS;
        private IntPtr hHandle;
        private IntPtr pBuffer;
        unsafe public void Attach(string SharedMemoryName, UInt32 NumBytes)
        {
            if (IntPtr.Zero != hHandle) return;
            hHandle = OpenFileMapping(FILE_MAP_ALL_ACCESS, false, SharedMemoryName);
            if (IntPtr.Zero == hHandle) return;
            pBuffer = MapViewOfFile(hHandle, FILE_MAP_ALL_ACCESS, 0, 0, &NumBytes);
        }
        public void Detach()
        {
            if (IntPtr.Zero != hHandle)
            {
                CloseHandle(hHandle); //fair to leak if can't close
                hHandle = IntPtr.Zero;
            }
            pBuffer = IntPtr.Zero;
            lBufferSize = 0;
        }

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