private unsafe void CreateLocalCopyFromIStreamSource(
NativeInterfaces.IShellItem item,
IFileTransferProgressEvents progressEvents,
out string pathNameResult)
{
string fileName = null;
item.GetDisplayName(NativeConstants.SIGDN.SIGDN_NORMALDISPLAY, out fileName);
string pathName = FileSystem.GetTempPathName(fileName);
Guid bhidStream = NativeConstants.BHID_Stream;
Guid iid_IStream = new Guid(NativeConstants.IID_IStream);
NativeInterfaces.IStream iStream = null;
item.BindToHandler(IntPtr.Zero, ref bhidStream, ref iid_IStream, out iStream);
try
{
VerifyNotCanceled();
NativeStructs.STATSTG statstg = new NativeStructs.STATSTG();
iStream.Stat(out statstg, NativeConstants.STATFLAG.STATFLAG_NONAME);
progressEvents.SetItemWorkTotal((long)statstg.cbSize);
const int bufSize = 4096;
byte[] buffer = new byte[bufSize];
fixed(void *pbBuffer = buffer)
{
IntPtr pbBuffer2 = new IntPtr(pbBuffer);
ulong qwBytesLeft = statstg.cbSize;
using (FileStream localFile = new FileStream(pathName, FileMode.Create, FileAccess.Write, FileShare.Read))
{
VerifyNotCanceled();
// NOTE: We do not call VerifyNotCanceled() during any individual item. This is because, while testing
// this, it was determined that oftentimes the transfer gets very confused if we just stop
// calling Read() and jump straight to Marshal.ReleaseComObject(). By "confused" I mean that
// the "Canceling..." text would remain on the progress dialog for up to a minute, and then
// the blinking light on the camera would continue indefinitely and you wouldn't be able to
// use the camera again until you unplugged it and plugged it back in.
while (qwBytesLeft > 0)
{
uint wantToRead = (uint)Math.Min(qwBytesLeft, bufSize);
uint amtRead = 0;
iStream.Read(pbBuffer2, wantToRead, out amtRead);
if (amtRead > qwBytesLeft)
{
throw new InvalidOperationException("IStream::Read() reported that more bytes were read than were in the file");
}
qwBytesLeft -= amtRead;
localFile.Write(buffer, 0, (int)amtRead);
progressEvents.SetItemWorkProgress((long)(statstg.cbSize - qwBytesLeft));
}
}
VerifyNotCanceled();
}
}
finally
{
if (iStream != null)
{
try
{
Marshal.ReleaseComObject(iStream);
}
catch (Exception)
{
}
iStream = null;
}
}
pathNameResult = pathName;
}
private unsafe void CreateLocalCopyFromIStreamSource(
NativeInterfaces.IShellItem item,
IFileTransferProgressEvents progressEvents,
out string pathNameResult)
{
string fileName = null;
item.GetDisplayName(NativeConstants.SIGDN.SIGDN_NORMALDISPLAY, out fileName);
string pathName = FileSystem.GetTempPathName(fileName);
Guid bhidStream = NativeConstants.BHID_Stream;
Guid iid_IStream = new Guid(NativeConstants.IID_IStream);
NativeInterfaces.IStream iStream = null;
item.BindToHandler(IntPtr.Zero, ref bhidStream, ref iid_IStream, out iStream);
try
{
VerifyNotCanceled();
NativeStructs.STATSTG statstg = new NativeStructs.STATSTG();
iStream.Stat(out statstg, NativeConstants.STATFLAG.STATFLAG_NONAME);
progressEvents.SetItemWorkTotal((long)statstg.cbSize);
const int bufSize = 4096;
byte[] buffer = new byte[bufSize];
fixed (void* pbBuffer = buffer)
{
IntPtr pbBuffer2 = new IntPtr(pbBuffer);
ulong qwBytesLeft = statstg.cbSize;
using (FileStream localFile = new FileStream(pathName, FileMode.Create, FileAccess.Write, FileShare.Read))
{
VerifyNotCanceled();
// NOTE: We do not call VerifyNotCanceled() during any individual item. This is because, while testing
// this, it was determined that oftentimes the transfer gets very confused if we just stop
// calling Read() and jump straight to Marshal.ReleaseComObject(). By "confused" I mean that
// the "Canceling..." text would remain on the progress dialog for up to a minute, and then
// the blinking light on the camera would continue indefinitely and you wouldn't be able to
// use the camera again until you unplugged it and plugged it back in.
while (qwBytesLeft > 0)
{
uint wantToRead = (uint)Math.Min(qwBytesLeft, bufSize);
uint amtRead = 0;
iStream.Read(pbBuffer2, wantToRead, out amtRead);
if (amtRead > qwBytesLeft)
{
throw new InvalidOperationException("IStream::Read() reported that more bytes were read than were in the file");
}
qwBytesLeft -= amtRead;
localFile.Write(buffer, 0, (int)amtRead);
progressEvents.SetItemWorkProgress((long)(statstg.cbSize - qwBytesLeft));
}
}
VerifyNotCanceled();
}
}
finally
{
if (iStream != null)
{
try
{
Marshal.ReleaseComObject(iStream);
}
catch (Exception)
{
}
iStream = null;
}
}
pathNameResult = pathName;
}
