Fixed issue with exception attempting to access protected memory

OutlookDataObject.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Runtime.InteropServices;
using System.Runtime.InteropServices.ComTypes;
using System.Reflection;
using System.IO;
using System.Windows;

namespace Helpers
{
    /// <summary>
    /// Provides a format-independant machanism for transfering data with support for outlook messages and attachments.
    /// </summary>
    public class OutlookDataObject : System.Windows.IDataObject
    {
        #region NativeMethods

        private class NativeMethods
        {
            [DllImport("kernel32.dll")]
            static extern IntPtr GlobalLock(IntPtr hMem);

            [DllImport("ole32.dll", PreserveSig = false)]
            public static extern ILockBytes CreateILockBytesOnHGlobal(IntPtr hGlobal, bool fDeleteOnRelease);

            [DllImport("OLE32.DLL", CharSet = CharSet.Auto, PreserveSig = false)]
            public static extern IntPtr GetHGlobalFromILockBytes(ILockBytes pLockBytes);

            [DllImport("OLE32.DLL", CharSet = CharSet.Unicode, PreserveSig = false)]
            public static extern IStorage StgCreateDocfileOnILockBytes(ILockBytes plkbyt, uint grfMode, uint reserved);

            [ComImport, InterfaceType(ComInterfaceType.InterfaceIsIUnknown), Guid("0000000B-0000-0000-C000-000000000046")]
            public interface IStorage
            {
                [return: MarshalAs(UnmanagedType.Interface)]
                IStream CreateStream([In, MarshalAs(UnmanagedType.BStr)] string pwcsName, [In, MarshalAs(UnmanagedType.U4)] int grfMode, [In, MarshalAs(UnmanagedType.U4)] int reserved1, [In, MarshalAs(UnmanagedType.U4)] int reserved2);
                [return: MarshalAs(UnmanagedType.Interface)]
                IStream OpenStream([In, MarshalAs(UnmanagedType.BStr)] string pwcsName, IntPtr reserved1, [In, MarshalAs(UnmanagedType.U4)] int grfMode, [In, MarshalAs(UnmanagedType.U4)] int reserved2);
                [return: MarshalAs(UnmanagedType.Interface)]
                IStorage CreateStorage([In, MarshalAs(UnmanagedType.BStr)] string pwcsName, [In, MarshalAs(UnmanagedType.U4)] int grfMode, [In, MarshalAs(UnmanagedType.U4)] int reserved1, [In, MarshalAs(UnmanagedType.U4)] int reserved2);
                [return: MarshalAs(UnmanagedType.Interface)]
                IStorage OpenStorage([In, MarshalAs(UnmanagedType.BStr)] string pwcsName, IntPtr pstgPriority, [In, MarshalAs(UnmanagedType.U4)] int grfMode, IntPtr snbExclude, [In, MarshalAs(UnmanagedType.U4)] int reserved);
                void CopyTo(int ciidExclude, [In, MarshalAs(UnmanagedType.LPArray)] Guid[] pIIDExclude, IntPtr snbExclude, [In, MarshalAs(UnmanagedType.Interface)] IStorage stgDest);
                void MoveElementTo([In, MarshalAs(UnmanagedType.BStr)] string pwcsName, [In, MarshalAs(UnmanagedType.Interface)] IStorage stgDest, [In, MarshalAs(UnmanagedType.BStr)] string pwcsNewName, [In, MarshalAs(UnmanagedType.U4)] int grfFlags);
                void Commit(int grfCommitFlags);
                void Revert();
                void EnumElements([In, MarshalAs(UnmanagedType.U4)] int reserved1, IntPtr reserved2, [In, MarshalAs(UnmanagedType.U4)] int reserved3, [MarshalAs(UnmanagedType.Interface)] out object ppVal);
                void DestroyElement([In, MarshalAs(UnmanagedType.BStr)] string pwcsName);
                void RenameElement([In, MarshalAs(UnmanagedType.BStr)] string pwcsOldName, [In, MarshalAs(UnmanagedType.BStr)] string pwcsNewName);
                void SetElementTimes([In, MarshalAs(UnmanagedType.BStr)] string pwcsName, [In] System.Runtime.InteropServices.ComTypes.FILETIME pctime, [In] System.Runtime.InteropServices.ComTypes.FILETIME patime, [In] System.Runtime.InteropServices.ComTypes.FILETIME pmtime);
                void SetClass([In] ref Guid clsid);
                void SetStateBits(int grfStateBits, int grfMask);
                void Stat([Out]out System.Runtime.InteropServices.ComTypes.STATSTG pStatStg, int grfStatFlag);
            }

            [ComImport, Guid("0000000A-0000-0000-C000-000000000046"), InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
            public interface ILockBytes
            {
                void ReadAt([In, MarshalAs(UnmanagedType.U8)] long ulOffset, [Out, MarshalAs(UnmanagedType.LPArray, SizeParamIndex = 1)] byte[] pv, [In, MarshalAs(UnmanagedType.U4)] int cb, [Out, MarshalAs(UnmanagedType.LPArray)] int[] pcbRead);
                void WriteAt([In, MarshalAs(UnmanagedType.U8)] long ulOffset, IntPtr pv, [In, MarshalAs(UnmanagedType.U4)] int cb, [Out, MarshalAs(UnmanagedType.LPArray)] int[] pcbWritten);
                void Flush();
                void SetSize([In, MarshalAs(UnmanagedType.U8)] long cb);
                void LockRegion([In, MarshalAs(UnmanagedType.U8)] long libOffset, [In, MarshalAs(UnmanagedType.U8)] long cb, [In, MarshalAs(UnmanagedType.U4)] int dwLockType);
                void UnlockRegion([In, MarshalAs(UnmanagedType.U8)] long libOffset, [In, MarshalAs(UnmanagedType.U8)] long cb, [In, MarshalAs(UnmanagedType.U4)] int dwLockType);
                void Stat([Out]out System.Runtime.InteropServices.ComTypes.STATSTG pstatstg, [In, MarshalAs(UnmanagedType.U4)] int grfStatFlag);
            }

            [StructLayout(LayoutKind.Sequential)]
            public sealed class POINTL
            {
                public int x;
                public int y;
            }

            [StructLayout(LayoutKind.Sequential)]
            public sealed class SIZEL
            {
                public int cx;
                public int cy;
            }

            [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi)]
            public sealed class FILEGROUPDESCRIPTORA
            {
                public uint cItems;
                public FILEDESCRIPTORA fgd;
            }

            [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi)]
            public sealed class FILEDESCRIPTORA
            {
                public uint dwFlags;
                public Guid clsid;
                public SIZEL sizel;
                public POINTL pointl;
                public uint dwFileAttributes;
                public System.Runtime.InteropServices.ComTypes.FILETIME ftCreationTime;
                public System.Runtime.InteropServices.ComTypes.FILETIME ftLastAccessTime;
                public System.Runtime.InteropServices.ComTypes.FILETIME ftLastWriteTime;
                public uint nFileSizeHigh;
                public uint nFileSizeLow;
                [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 260)]
                public string cFileName;
            }

            [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
            public sealed class FILEGROUPDESCRIPTORW
            {
                public uint cItems;
                public FILEDESCRIPTORW fgd;
            }

            [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
            public sealed class FILEDESCRIPTORW
            {
                public uint dwFlags;
                public Guid clsid;
                public SIZEL sizel;
                public POINTL pointl;
                public uint dwFileAttributes;
                public System.Runtime.InteropServices.ComTypes.FILETIME ftCreationTime;
                public System.Runtime.InteropServices.ComTypes.FILETIME ftLastAccessTime;
                public System.Runtime.InteropServices.ComTypes.FILETIME ftLastWriteTime;
                public uint nFileSizeHigh;
                public uint nFileSizeLow;
                [MarshalAs(UnmanagedType.ByValTStr, SizeConst = 260)]
                public string cFileName;
            }
        }

        #endregion

        #region Property(s)

        /// <summary>
        /// Holds the <see cref="System.Windows.IDataObject"/> that this class is wrapping
        /// </summary>
        private System.Windows.IDataObject underlyingDataObject;

        /// <summary>
        /// Holds the <see cref="System.Runtime.InteropServices.ComTypes.IDataObject"/> interface to the <see cref="System.Windows.IDataObject"/> that this class is wrapping.
        /// </summary>
        private System.Runtime.InteropServices.ComTypes.IDataObject comUnderlyingDataObject;

        /// <summary>
        /// Holds the internal ole <see cref="System.Windows.IDataObject"/> to the <see cref="System.Windows.IDataObject"/> that this class is wrapping.
        /// </summary>
        private System.Windows.IDataObject oleUnderlyingDataObject;

        /// <summary>
        /// Holds the <see cref="MethodInfo"/> of the "GetDataFromHGLOBAL" method of the internal ole <see cref="System.Windows.IDataObject"/>.
        /// </summary>
        private MethodInfo getDataFromHGLOBALMethod;

        #endregion

        #region Constructor(s)

        /// <summary>
        /// Initializes a new instance of the <see cref="OutlookDataObject"/> class.
        /// </summary>
        /// <param name="underlyingDataObject">The underlying data object to wrap.</param>
        public OutlookDataObject(System.Windows.IDataObject underlyingDataObject)
        {
            //get the underlying dataobject and its ComType IDataObject interface to it
            this.underlyingDataObject = underlyingDataObject;
            this.comUnderlyingDataObject = (System.Runtime.InteropServices.ComTypes.IDataObject)this.underlyingDataObject;

            //get the internal ole dataobject and its GetDataFromHGLOBAL so it can be called later
            FieldInfo innerDataField = this.underlyingDataObject.GetType().GetField("_innerData", BindingFlags.NonPublic | BindingFlags.Instance);
            this.oleUnderlyingDataObject = (System.Windows.IDataObject)innerDataField.GetValue(this.underlyingDataObject);
            this.getDataFromHGLOBALMethod = this.oleUnderlyingDataObject.GetType().GetMethod("GetDataFromHGLOBAL", BindingFlags.NonPublic | BindingFlags.Instance);
        }

        #endregion

        #region IDataObject Members

        /// <summary>
        /// Retrieves the data associated with the specified class type format.
        /// </summary>
        /// <param name="format">A <see cref="T:System.Type"></see> representing the format of the data to retrieve. See <see cref="T:System.Windows.DataFormats"></see> for predefined formats.</param>
        /// <returns>
        /// The data associated with the specified format, or null.
        /// </returns>
        public object GetData(Type format)
        {
            return this.GetData(format.FullName);
        }

        /// <summary>
        /// Retrieves the data associated with the specified data format.
        /// </summary>
        /// <param name="format">The format of the data to retrieve. See <see cref="T:System.Windows.DataFormats"></see> for predefined formats.</param>
        /// <returns>
        /// The data associated with the specified format, or null.
        /// </returns>
        public object GetData(string format)
        {
            return this.GetData(format, true);
        }

        /// <summary>
        /// Retrieves the data associated with the specified data format, using a Boolean to determine whether to convert the data to the format.
        /// </summary>
        /// <param name="format">The format of the data to retrieve. See <see cref="T:System.Windows.DataFormats"></see> for predefined formats.</param>
        /// <param name="autoConvert">true to convert the data to the specified format; otherwise, false.</param>
        /// <returns>
        /// The data associated with the specified format, or null.
        /// </returns>
        public object GetData(string format, bool autoConvert)
        {
            //handle the "FileGroupDescriptor" and "FileContents" format request in this class otherwise pass through to underlying IDataObject 
            switch (format)
            {
                case "FileGroupDescriptor":
                    //override the default handling of FileGroupDescriptor which returns a
                    //MemoryStream and instead return a string array of file names
                    IntPtr fileGroupDescriptorAPointer = IntPtr.Zero;
                    try
                    {
                        //use the underlying IDataObject to get the FileGroupDescriptor as a MemoryStream
                        MemoryStream fileGroupDescriptorStream = (MemoryStream)this.underlyingDataObject.GetData("FileGroupDescriptor", autoConvert);
                        byte[] fileGroupDescriptorBytes = new byte[fileGroupDescriptorStream.Length];
                        fileGroupDescriptorStream.Read(fileGroupDescriptorBytes, 0, fileGroupDescriptorBytes.Length);
                        fileGroupDescriptorStream.Close();

                        //copy the file group descriptor into unmanaged memory 
                        fileGroupDescriptorAPointer = Marshal.AllocHGlobal(fileGroupDescriptorBytes.Length);
                        Marshal.Copy(fileGroupDescriptorBytes, 0, fileGroupDescriptorAPointer, fileGroupDescriptorBytes.Length);

                        ////marshal the unmanaged memory to to FILEGROUPDESCRIPTORA struct
                        //FIX FROM - https://stackoverflow.com/questions/27173844/accessviolationexception-after-copying-a-file-from-inside-a-zip-archive-to-the-c
                        int ITEMCOUNT = Marshal.ReadInt32(fileGroupDescriptorAPointer);
                        
                        //create a new array to store file names in of the number of items in the file group descriptor
                        string[] fileNames = new string[ITEMCOUNT];

                        //get the pointer to the first file descriptor
                        IntPtr fileDescriptorPointer = (IntPtr)((long)fileGroupDescriptorAPointer + Marshal.SizeOf(ITEMCOUNT));

                        //loop for the number of files acording to the file group descriptor
                        for (int fileDescriptorIndex = 0; fileDescriptorIndex < ITEMCOUNT; fileDescriptorIndex++)
                        {
                            //marshal the pointer top the file descriptor as a FILEDESCRIPTORA struct and get the file name
                            NativeMethods.FILEDESCRIPTORA fileDescriptor = (NativeMethods.FILEDESCRIPTORA)Marshal.PtrToStructure(fileDescriptorPointer, typeof(NativeMethods.FILEDESCRIPTORA));
                            fileNames[fileDescriptorIndex] = fileDescriptor.cFileName;

                            //move the file descriptor pointer to the next file descriptor
                            fileDescriptorPointer = (IntPtr)((long)fileDescriptorPointer + Marshal.SizeOf(fileDescriptor));
                        }

                        //return the array of filenames
                        return fileNames;
                    }
                    finally
                    {
                        //free unmanaged memory pointer
                        Marshal.FreeHGlobal(fileGroupDescriptorAPointer);
                    }

                case "FileGroupDescriptorW":
                    //override the default handling of FileGroupDescriptorW which returns a
                    //MemoryStream and instead return a string array of file names
                    IntPtr fileGroupDescriptorWPointer = IntPtr.Zero;
                    try
                    {
                        //use the underlying IDataObject to get the FileGroupDescriptorW as a MemoryStream
                        MemoryStream fileGroupDescriptorStream = (MemoryStream)this.underlyingDataObject.GetData("FileGroupDescriptorW");
                        byte[] fileGroupDescriptorBytes = new byte[fileGroupDescriptorStream.Length];
                        fileGroupDescriptorStream.Read(fileGroupDescriptorBytes, 0, fileGroupDescriptorBytes.Length);
                        fileGroupDescriptorStream.Close();

                        //copy the file group descriptor into unmanaged memory
                        fileGroupDescriptorWPointer = Marshal.AllocHGlobal(fileGroupDescriptorBytes.Length);
                        Marshal.Copy(fileGroupDescriptorBytes, 0, fileGroupDescriptorWPointer, fileGroupDescriptorBytes.Length);

                        //marshal the unmanaged memory to to FILEGROUPDESCRIPTORW struct
                        //FIX FROM - https://stackoverflow.com/questions/27173844/accessviolationexception-after-copying-a-file-from-inside-a-zip-archive-to-the-c
                        int ITEMCOUNT = Marshal.ReadInt32(fileGroupDescriptorWPointer);

                        //create a new array to store file names in of the number of items in the file group descriptor
                        string[] fileNames = new string[ITEMCOUNT];

                        //get the pointer to the first file descriptor
                        IntPtr fileDescriptorPointer = (IntPtr)((long)fileGroupDescriptorWPointer + Marshal.SizeOf(ITEMCOUNT));

                        //loop for the number of files acording to the file group descriptor
                        for (int fileDescriptorIndex = 0; fileDescriptorIndex < ITEMCOUNT; fileDescriptorIndex++)
                        {
                            //marshal the pointer top the file descriptor as a FILEDESCRIPTORW struct and get the file name
                            NativeMethods.FILEDESCRIPTORW fileDescriptor = (NativeMethods.FILEDESCRIPTORW)Marshal.PtrToStructure(fileDescriptorPointer, typeof(NativeMethods.FILEDESCRIPTORW));
                            fileNames[fileDescriptorIndex] = fileDescriptor.cFileName;

                            //move the file descriptor pointer to the next file descriptor
                            fileDescriptorPointer = (IntPtr)((long)fileDescriptorPointer + Marshal.SizeOf(fileDescriptor));
                        }

                        //return the array of filenames
                        return fileNames;
                    }
                    finally
                    {
                        //free unmanaged memory pointer
                        Marshal.FreeHGlobal(fileGroupDescriptorWPointer);
                    }

                case "FileContents":
                    //override the default handling of FileContents which returns the
                    //contents of the first file as a memory stream and instead return                    
                    //a array of MemoryStreams containing the data to each file dropped                    
                    //
                    // FILECONTENTS requires a companion FILEGROUPDESCRIPTOR to be                     
                    // available so we bail out if we don't find one in the data object.

                    string fgdFormatName;
                    if (GetDataPresent("FileGroupDescriptorW"))
                        fgdFormatName = "FileGroupDescriptorW";
                    else if (GetDataPresent("FileGroupDescriptor"))
                        fgdFormatName = "FileGroupDescriptor";
                    else
                        return null;
                    //get the array of filenames which lets us know how many file contents exist                    
                    string[] fileContentNames = (string[])this.GetData(fgdFormatName);

                    //create a MemoryStream array to store the file contents
                    MemoryStream[] fileContents = new MemoryStream[fileContentNames.Length];

                    //loop for the number of files acording to the file names
                    for (int fileIndex = 0; fileIndex < fileContentNames.Length; fileIndex++)
                    {
                        //get the data at the file index and store in array
                        fileContents[fileIndex] = this.GetData(format, fileIndex);
                    }

                    //return array of MemoryStreams containing file contents
                    return fileContents;
            }

            //use underlying IDataObject to handle getting of data
            return this.underlyingDataObject.GetData(format, autoConvert);
        }

        /// <summary>
        /// Retrieves the data associated with the specified data format at the specified index.
        /// </summary>
        /// <param name="format">The format of the data to retrieve. See <see cref="T:System.Windows.DataFormats"></see> for predefined formats.</param>
        /// <param name="index">The index of the data to retrieve.</param>
        /// <returns>
        /// A <see cref="MemoryStream"/> containing the raw data for the specified data format at the specified index.
        /// </returns>
        public MemoryStream GetData(string format, int index)
        {
            //create a FORMATETC struct to request the data with
            FORMATETC formatetc = new FORMATETC();
            formatetc.cfFormat = (short)DataFormats.GetDataFormat(format).Id;
            formatetc.dwAspect = DVASPECT.DVASPECT_CONTENT;
            formatetc.lindex = index;
            formatetc.ptd = new IntPtr(0);
            formatetc.tymed = TYMED.TYMED_ISTREAM | TYMED.TYMED_ISTORAGE | TYMED.TYMED_HGLOBAL;

            //create STGMEDIUM to output request results into
            STGMEDIUM medium = new STGMEDIUM();

            //using the Com IDataObject interface get the data using the defined FORMATETC
            this.comUnderlyingDataObject.GetData(ref formatetc, out medium);

            //retrieve the data depending on the returned store type
            switch (medium.tymed)
            {
                case TYMED.TYMED_ISTORAGE:
                    //to handle a IStorage it needs to be written into a second unmanaged
                    //memory mapped storage and then the data can be read from memory into
                    //a managed byte and returned as a MemoryStream

                    NativeMethods.IStorage iStorage = null;
                    NativeMethods.IStorage iStorage2 = null;
                    NativeMethods.ILockBytes iLockBytes = null;
                    System.Runtime.InteropServices.ComTypes.STATSTG iLockBytesStat;
                    try
                    {
                        //marshal the returned pointer to a IStorage object
                        iStorage = (NativeMethods.IStorage)Marshal.GetObjectForIUnknown(medium.unionmember);
                        Marshal.Release(medium.unionmember);

                        //create a ILockBytes (unmanaged byte array) and then create a IStorage using the byte array as a backing store
                        iLockBytes = NativeMethods.CreateILockBytesOnHGlobal(IntPtr.Zero, true);
                        iStorage2 = NativeMethods.StgCreateDocfileOnILockBytes(iLockBytes, 0x00001012, 0);

                        //copy the returned IStorage into the new IStorage
                        iStorage.CopyTo(0, null, IntPtr.Zero, iStorage2);
                        iLockBytes.Flush();
                        iStorage2.Commit(0);

                        //get the STATSTG of the ILockBytes to determine how many bytes were written to it
                        iLockBytesStat = new System.Runtime.InteropServices.ComTypes.STATSTG();
                        iLockBytes.Stat(out iLockBytesStat, 1);
                        int iLockBytesSize = (int)iLockBytesStat.cbSize;

                        //read the data from the ILockBytes (unmanaged byte array) into a managed byte array
                        byte[] iLockBytesContent = new byte[iLockBytesSize];
                        iLockBytes.ReadAt(0, iLockBytesContent, iLockBytesContent.Length, null);

                        //wrapped the managed byte array into a memory stream and return it
                        return new MemoryStream(iLockBytesContent);
                    }
                    finally
                    {
                        //release all unmanaged objects
                        Marshal.ReleaseComObject(iStorage2);
                        Marshal.ReleaseComObject(iLockBytes);
                        Marshal.ReleaseComObject(iStorage);
                    }

                case TYMED.TYMED_ISTREAM:
                    //to handle a IStream it needs to be read into a managed byte and
                    //returned as a MemoryStream

                    IStream iStream = null;
                    System.Runtime.InteropServices.ComTypes.STATSTG iStreamStat;
                    try
                    {
                        //marshal the returned pointer to a IStream object
                        iStream = (IStream)Marshal.GetObjectForIUnknown(medium.unionmember);
                        Marshal.Release(medium.unionmember);

                        //get the STATSTG of the IStream to determine how many bytes are in it
                        iStreamStat = new System.Runtime.InteropServices.ComTypes.STATSTG();
                        iStream.Stat(out iStreamStat, 0);
                        int iStreamSize = (int)iStreamStat.cbSize;

                        //read the data from the IStream into a managed byte array
                        byte[] iStreamContent = new byte[iStreamSize];
                        iStream.Read(iStreamContent, iStreamContent.Length, IntPtr.Zero);

                        //wrapped the managed byte array into a memory stream and return it
                        return new MemoryStream(iStreamContent);
                    }
                    finally
                    {
                        //release all unmanaged objects
                        Marshal.ReleaseComObject(iStream);
                    }

                case TYMED.TYMED_HGLOBAL:
                    //to handle a HGlobal the exisitng "GetDataFromHGLOBAL" method is invoked via
                    //reflection

                    return (MemoryStream)this.getDataFromHGLOBALMethod.Invoke(this.oleUnderlyingDataObject, new object[] { DataFormats.GetDataFormat((short)formatetc.cfFormat).Name, medium.unionmember });
            }

            return null;
        }

        /// <summary>
        /// Determines whether data stored in this instance is associated with, or can be converted to, the specified format.
        /// </summary>
        /// <param name="format">A <see cref="T:System.Type"></see> representing the format for which to check. See <see cref="T:System.Windows.DataFormats"></see> for predefined formats.</param>
        /// <returns>
        /// true if data stored in this instance is associated with, or can be converted to, the specified format; otherwise, false.
        /// </returns>
        public bool GetDataPresent(Type format)
        {
            return this.underlyingDataObject.GetDataPresent(format);
        }

        /// <summary>
        /// Determines whether data stored in this instance is associated with, or can be converted to, the specified format.
        /// </summary>
        /// <param name="format">The format for which to check. See <see cref="T:System.Windows.DataFormats"></see> for predefined formats.</param>
        /// <returns>
        /// true if data stored in this instance is associated with, or can be converted to, the specified format; otherwise false.
        /// </returns>
        public bool GetDataPresent(string format)
        {
            return this.underlyingDataObject.GetDataPresent(format);
        }

        /// <summary>
        /// Determines whether data stored in this instance is associated with the specified format, using a Boolean value to determine whether to convert the data to the format.
        /// </summary>
        /// <param name="format">The format for which to check. See <see cref="T:System.Windows.DataFormats"></see> for predefined formats.</param>
        /// <param name="autoConvert">true to determine whether data stored in this instance can be converted to the specified format; false to check whether the data is in the specified format.</param>
        /// <returns>
        /// true if the data is in, or can be converted to, the specified format; otherwise, false.
        /// </returns>
        public bool GetDataPresent(string format, bool autoConvert)
        {
            return this.underlyingDataObject.GetDataPresent(format, autoConvert);
        }

        /// <summary>
        /// Returns a list of all formats that data stored in this instance is associated with or can be converted to.
        /// </summary>
        /// <returns>
        /// An array of the names that represents a list of all formats that are supported by the data stored in this object.
        /// </returns>
        public string[] GetFormats()
        {
            return this.underlyingDataObject.GetFormats();
        }

        /// <summary>
        /// Gets a list of all formats that data stored in this instance is associated with or can be converted to, using a Boolean value to determine whether to retrieve all formats that the data can be converted to or only native data formats.
        /// </summary>
        /// <param name="autoConvert">true to retrieve all formats that data stored in this instance is associated with or can be converted to; false to retrieve only native data formats.</param>
        /// <returns>
        /// An array of the names that represents a list of all formats that are supported by the data stored in this object.
        /// </returns>
        public string[] GetFormats(bool autoConvert)
        {
            return this.underlyingDataObject.GetFormats(autoConvert);
        }

        /// <summary>
        /// Stores the specified data in this instance, using the class of the data for the format.
        /// </summary>
        /// <param name="data">The data to store.</param>
        public void SetData(object data)
        {
            this.underlyingDataObject.SetData(data);
        }

        /// <summary>
        /// Stores the specified data and its associated class type in this instance.
        /// </summary>
        /// <param name="format">A <see cref="T:System.Type"></see> representing the format associated with the data. See <see cref="T:System.Windows.DataFormats"></see> for predefined formats.</param>
        /// <param name="data">The data to store.</param>
        public void SetData(Type format, object data)
        {
            this.underlyingDataObject.SetData(format, data);
        }

        /// <summary>
        /// Stores the specified data and its associated format in this instance.
        /// </summary>
        /// <param name="format">The format associated with the data. See <see cref="T:System.Windows.DataFormats"></see> for predefined formats.</param>
        /// <param name="data">The data to store.</param>
        public void SetData(string format, object data)
        {
            this.underlyingDataObject.SetData(format, data);
        }

        /// <summary>
        /// Stores the specified data and its associated format in this instance, using a Boolean value to specify whether the data can be converted to another format.
        /// </summary>
        /// <param name="format">The format associated with the data. See <see cref="T:System.Windows.DataFormats"></see> for predefined formats.</param>
        /// <param name="autoConvert">true to allow the data to be converted to another format; otherwise, false.</param>
        /// <param name="data">The data to store.</param>
        public void SetData(string format, object data, bool autoConvert)
        {
            this.underlyingDataObject.SetData(format, data, autoConvert);
        }

        #endregion
    }
}

Hi There,
I am from a software company. Our application is using the exactly same source code as above to allow users to drag and drop files or documents to our application, it even can allow to drag an attachment from Outlook to our application. It works fine.
But it comes to Outlook Version 2006 (Build 13001.20384 Click-to-Run), it failed to drag an attachment from Outlook to our application.
It fails at the line below:
Dim fileGroupDescriptorObject As Object = Marshal.PtrToStructure(fileGroupDescriptorWPointer, GetType(NativeMethods.FileGroupDescriptorw))
Then we modified our source code exactly same as line 282, it still fail anyway.
You may get the dummy application to debug via the link below:
https://drive.google.com/file/d/1PuhPa8RAWTwduzQMPG9EpF5Vidy-X9jH/view?usp=sharing
Just drag the attachment from an Outlook e-mail to the application and if successfully, it will prompt the messagebox with the file name of the attachment.
I would like to gather some ideas to figure out what's wrong. Thanks.
Best Regards,
Jun Wei

Hey Jun Wei, have you found a solution perhaps?

Hi there, this issue has been resolved by windows updating. Thanks.

Could you please tell me on which version of windows it resolved it self?

Thank you

Hello,
Is this code (class) under any license?
If so, which one, please?
I would like to use it in a commercial application

Thank you.

After days of trying and an exhausting search, finally a class that works. There are a few variations of this class around but this is the only one I've come across, for WPF, that actually works, and glad to say its still working in 2024. Massive thanks.

After days of trying and an exhausting search, finally a class that works. There are a few variations of this class around but this is the only one I've come across, for WPF, that actually works, and glad to say its still working in 2024. Massive thanks.

It's not working for me are you dragging an email from outlook (New version) into your wpf app? I simply get a "Can't cast DataObject to OutlookDataObject" error :(