問題が発生しているので、ここの誰かが助けてくれることを願っています。
このOutlookDataObjectプロジェクトから多少変更されたコードを使用して、Outlookなどのさまざまなメールクライアントからドロップされたファイルと、クリップボードを介したファイルの一般的なコピー貼り付けを処理してファイルシステムに保存します。
ほとんどの場合は正常に機能しますが、ユーザーがWindowsエクスプローラーでZIPファイルを開き、そこからファイルをコピーして追加しようとすると、FileContentDataObjectのGetDataメソッドの次の部分でAccessViolationExceptionが発生します。
//marshal the unmanaged memory to to FILEGROUPDESCRIPTORW struct
object fileGroupDescriptorObject = Marshal.PtrToStructure(fileGroupDescriptorWPointer, typeof(NativeMethods.FILEGROUPDESCRIPTORW));
これは、この問題を再現できるはずの問題のコード全体の縮小版です。
// Starting Method
public void InsertFromClipboard()
{
FileContentDataObjectBase dataObject = GetDataObject();
if(dataObject!= null)
{
dataObject.SaveToFileSystem("C:/temp");
}
}
private FileContentDataObjectBase GetDataObject()
{
var dataObject = System.Windows.Forms.Clipboard.GetDataObject();
return new FileContentDataObject(System.Windows.Forms.Clipboard.GetDataObject());
}
public class FileContentDataObject : FileContentDataObjectBase
{
/// <summary>
/// Initializes a new instance of the <see cref="OutlookDataObject"/> class.
/// </summary>
/// <param name="underlyingDataObject">The underlying data object to wrap.</param>
public FileContentDataObject(System.Windows.Forms.IDataObject underlyingDataObject)
: base(underlyingDataObject) { }
public override void SaveToFileSystem(string path)
{
string[] filenames;
//get the names and data streams of the files dropped
if (this.GetFormats().Contains("FileGroupDescriptor"))
filenames = (string[])this.GetData("FileGroupDescriptor", true);
else if (this.GetFormats().Contains("FileGroupDescriptorW"))
filenames = (string[])this.GetData("FileGroupDescriptorW", true);
else
return;
MemoryStream[] filestreams = (MemoryStream[])this.GetData("FileContents");
SaveToFileSystem(filenames, filestreams, path);
}
public new object GetData(string format, bool autoConvert)
{
switch (format)
{
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
object fileGroupDescriptorObject = Marshal.PtrToStructure(fileGroupDescriptorWPointer, typeof(NativeMethods.FILEGROUPDESCRIPTORW));
NativeMethods.FILEGROUPDESCRIPTORW fileGroupDescriptor = (NativeMethods.FILEGROUPDESCRIPTORW)fileGroupDescriptorObject;
//create a new array to store file names in of the number of items in the file group descriptor
string[] fileNames = new string[fileGroupDescriptor.cItems];
//get the pointer to the first file descriptor
IntPtr fileDescriptorPointer = (IntPtr)((int)fileGroupDescriptorWPointer + Marshal.SizeOf(fileGroupDescriptor.cItems));
//loop for the number of files acording to the file group descriptor
for (int fileDescriptorIndex = 0; fileDescriptorIndex < fileGroupDescriptor.cItems; 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)((int)fileDescriptorPointer + Marshal.SizeOf(fileDescriptor));
}
//return the array of filenames
return fileNames;
}
finally
{
//free unmanaged memory pointer
Marshal.FreeHGlobal(fileGroupDescriptorWPointer);
}
}
//use underlying IDataObject to handle getting of data
return this.underlyingDataObject.GetData(format, autoConvert);
}
}
public abstract class FileContentDataObjectBase : System.Windows.Forms.IDataObject
{
#region NativeMethods
protected class NativeMethods
{
[DllImport("kernel32.dll")]
static extern IntPtr GlobalLock(IntPtr hMem);
[DllImport("ole32.dll", PreserveSig = false)]
internal static extern ILockBytes CreateILockBytesOnHGlobal(IntPtr hGlobal, bool fDeleteOnRelease);
[DllImport("OLE32.DLL", CharSet = CharSet.Auto, PreserveSig = false)]
internal static extern IntPtr GetHGlobalFromILockBytes(ILockBytes pLockBytes);
[DllImport("OLE32.DLL", CharSet = CharSet.Unicode, PreserveSig = false)]
internal static extern IStorage StgCreateDocfileOnILockBytes(ILockBytes plkbyt, uint grfMode, uint reserved);
[ComImport, InterfaceType(ComInterfaceType.InterfaceIsIUnknown), Guid("0000000B-0000-0000-C000-000000000046")]
internal 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)]
internal 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)]
internal sealed class POINTL
{
public int x;
public int y;
}
[StructLayout(LayoutKind.Sequential)]
internal sealed class SIZEL
{
public int cx;
public int cy;
}
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi)]
internal sealed class FILEGROUPDESCRIPTORA
{
public uint cItems;
public FILEDESCRIPTORA[] fgd;
}
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi)]
internal 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)]
internal sealed class FILEGROUPDESCRIPTORW
{
public uint cItems;
public FILEDESCRIPTORW[] fgd;
}
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
internal 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.Forms.IDataObject"/> that this class is wrapping
/// </summary>
protected System.Windows.Forms.IDataObject underlyingDataObject;
/// <summary>
/// Holds the <see cref="System.Runtime.InteropServices.ComTypes.IDataObject"/> interface to the <see cref="System.Windows.Forms.IDataObject"/> that this class is wrapping.
/// </summary>
protected System.Runtime.InteropServices.ComTypes.IDataObject comUnderlyingDataObject;
/// <summary>
/// Holds the internal ole <see cref="System.Windows.Forms.IDataObject"/> to the <see cref="System.Windows.Forms.IDataObject"/> that this class is wrapping.
/// </summary>
protected System.Windows.Forms.IDataObject oleUnderlyingDataObject;
/// <summary>
/// Holds the <see cref="MethodInfo"/> of the "GetDataFromHGLOBLAL" method of the internal ole <see cref="System.Windows.Forms.IDataObject"/>.
/// </summary>
protected MethodInfo getDataFromHGLOBLALMethod;
#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 FileContentDataObjectBase(System.Windows.Forms.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 GetDataFromHGLOBLAL so it can be called later
FieldInfo innerDataField = this.underlyingDataObject.GetType().GetField("innerData", BindingFlags.NonPublic | BindingFlags.Instance);
this.oleUnderlyingDataObject = (System.Windows.Forms.IDataObject)innerDataField.GetValue(this.underlyingDataObject);
this.getDataFromHGLOBLALMethod = this.oleUnderlyingDataObject.GetType().GetMethod("GetDataFromHGLOBLAL", 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.Forms.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.Forms.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.Forms.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)
{
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.Forms.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.GetFormat(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 "GetDataFromHGLOBLAL" method is invoked via
//reflection
return (MemoryStream)this.getDataFromHGLOBLALMethod.Invoke(this.oleUnderlyingDataObject, new object[] { DataFormats.GetFormat((short)formatetc.cfFormat).Name, medium.unionmember });
}
return null;
}
/// <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);
}
#endregion
#region methods
public static void SaveToFileSystem(string[] filenames, MemoryStream[] filestreams, string path)
{
for (int fileIndex = 0; fileIndex < filenames.Length; fileIndex++)
{
try
{
//use the fileindex to get the name and data stream
string filename = filenames[fileIndex];
MemoryStream filestream = filestreams[fileIndex];
//save the file stream using its name to the application path
FileStream outputStream = File.Create(Path.Combine(path, GetStrippedFileName(filename)));
filestream.WriteTo(outputStream);
outputStream.Close();
}
catch (IOException ex)
{
throw new Exception(ex.Message, ex);
}
catch (SecurityException ex)
{
throw new Exception(ex.Message, ex);
}
}
}
public static void SaveToFileSystem(FileContentDataObjectBase dataObject, string path)
{
dataObject.SaveToFileSystem(path);
}
public abstract void SaveToFileSystem(string path);
private static string GetStrippedFileName(string input)
{
foreach (var chr in Path.GetInvalidFileNameChars())
input = input.Replace(chr.ToString(), String.Empty);
return input;
}
#endregion
}
なぜそれが起こるのか、そしてどうすれば問題を解決できるのかを理解したいと思います。
どんな助けや洞察も歓迎します。
前もって感謝します。
かなりの時間を探した後、この有益なコメントのおかげでようやく問題を見つけました。
使用した元のコードのFILEGROUPDESCRIPTORA宣言とFILEGROUPDESCRIPTORW宣言が間違っていることが判明したため、場合によってはAccessViolation例外が発生する可能性があります。
だから私はから説明されたコメンターのような宣言を変更しました...
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi)]
public sealed class FILEGROUPDESCRIPTORA
{
public uint cItems;
public FILEDESCRIPTORA[] fgd;
}
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
public sealed class FILEGROUPDESCRIPTORW
{
public uint cItems;
public FILEDESCRIPTORW[] fgd;
}
に...
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi)]
public sealed class FILEGROUPDESCRIPTORA
{
public uint cItems;
public FILEDESCRIPTORA fgd;
}
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
public sealed class FILEGROUPDESCRIPTORW
{
public uint cItems;
public FILEDESCRIPTORW fgd;
}
その後、AccessViolation Exceptionsはなくなり、質問でリンクした元のコードをもう少し変更するだけで機能しました。
クリップボードファイルの「FileContents」形式の処理中に、2つのFILEGROUPDESCRIPTORの正しいものが毎回使用されていることを確認するために、いくつかのチェックを追加する必要がありましたが、今では完全に機能します。
この記事はインターネットから収集されたものであり、転載の際にはソースを示してください。
侵害の場合は、連絡してください[email protected]
コメントを追加