When I get the image from the file the file remains locked

[**Developer**]

When I get the image from the file the file remains locked so the Delete
fails with a "used by another process"

So I tried using a clone and disposing the obtained image.

But that didn't fix the problem.

Can you help?

Dim zz As Image = Image.FromFile( imageFileName)

MyImage = zz.Clone

zz.Dispose()

zz = Nothing

File.Delete(ima geFileName)

[Lucky]

hi,
the problem here with cloning method is it also copies the reference
of the file that is loaded in the IMAGE object so that if you dispose
the zz object after cloning, it passes reference of the file to MyImage
object that's why ultimately the file remains locked.

try this code. this should solve your problem

Dim fs As New StreamReader("C :\all.jpg")
Dim img As Image = Image.FromStrea m(fs.BaseStream )
fs.Close()
PictureBox1.Ima ge = img
File.Delete("C: \all.jpg")
Lucky

[Michael D. Ober]

I'd really like to know if this works. The Kodak Image drivers in Windows
98 and NT4 have the same problem. I always thought this was a bug in the
Kodak drivers, but if it exists in .NET (which doesn't use the Kodak
drivers) as well, then the problem may actually be in the underlying Win32
API.

Mike Ober.

"Lucky" <tu************ @gmail.com> wrote in message
news:11******** **************@ o13g2000cwo.goo glegroups.com.. .

hi,
the problem here with cloning method is it also copies the reference
of the file that is loaded in the IMAGE object so that if you dispose
the zz object after cloning, it passes reference of the file to MyImage
object that's why ultimately the file remains locked.

try this code. this should solve your problem

Dim fs As New StreamReader("C :\all.jpg")
Dim img As Image = Image.FromStrea m(fs.BaseStream )
fs.Close()
PictureBox1.Ima ge = img
File.Delete("C: \all.jpg")
Lucky

[Lucky]

well first you need to understand the behaviour of the class and the
way it treats the resources.

in your case IMAGE class lock the resources so that if any call for
refresh/reload needs to attend by the object than the original data can
be reloaded or modified by the object itself.

i dont know why it is like this in IMAGE class but MS has implimented
it this way only.

run my code and compare it with your's and you'll see the difference
and behaviour of the class

Lucky

[R. MacDonald]

A bug, or a "feature"? I seem to recall a similar problem and found a
this reference that provided some insight.

http://support.microsoft.com/?id=814675

Cheers,
Randy

Michael D. Ober wrote:

I'd really like to know if this works. The Kodak Image drivers in Windows
98 and NT4 have the same problem. I always thought this was a bug in the
Kodak drivers, but if it exists in .NET (which doesn't use the Kodak
drivers) as well, then the problem may actually be in the underlying Win32
API.

Mike Ober.

"Lucky" <tu************ @gmail.com> wrote in message
news:11******** **************@ o13g2000cwo.goo glegroups.com.. .

hi,
the problem here with cloning method is it also copies the reference
of the file that is loaded in the IMAGE object so that if you dispose
the zz object after cloning, it passes reference of the file to MyImage
object that's why ultimately the file remains locked.

try this code. this should solve your problem

Dim fs As New StreamReader("C :\all.jpg")
Dim img As Image = Image.FromStrea m(fs.BaseStream )
fs.Close()
PictureBox1.I mage = img
File.Delete(" C:\all.jpg")
Lucky

[**Developer**]

Thanks a lot

"Lucky" <tu************ @gmail.com> wrote in message
news:11******** **************@ o13g2000cwo.goo glegroups.com.. .

hi,
the problem here with cloning method is it also copies the reference
of the file that is loaded in the IMAGE object so that if you dispose
the zz object after cloning, it passes reference of the file to MyImage
object that's why ultimately the file remains locked.

try this code. this should solve your problem

Dim fs As New StreamReader("C :\all.jpg")
Dim img As Image = Image.FromStrea m(fs.BaseStream )
fs.Close()
PictureBox1.Ima ge = img
File.Delete("C: \all.jpg")
Lucky

[Herfried K. Wagner [MVP]]

" **Developer**" <RE************ *@a-znet.com> schrieb:

When I get the image from the file the file remains locked so the Delete
fails with a "used by another process"

Check out the code snippets at
<URL:http://dotnet.mvps.org/dotnet/code/graphics/#ImageNoLock>.

--
M S Herfried K. Wagner
M V P <URL:http://dotnet.mvps.org/>
V B <URL:http://classicvb.org/petition/>

[**Developer**]

I don't think I can use your suggestion. I try to make it easy to see the
problem by shorting the code but I'm afriad I cut out too much code. Below
might be more then required to show the problem but I hope I didn't cut
anything relavent.

I believe the problen code starts where I left the blank lines below.

Dim wiaManager As WiaClass = Nothing ' WIA manager COM object

Dim wiaDevs As CollectionClass = Nothing ' WIA devices collection COM object

Dim wiaRoot As ItemClass = Nothing ' WIA root device COM object

Dim wiaPics As CollectionClass = Nothing ' WIA collection COM object

Dim wiaItem As ItemClass = Nothing ' WIA image COM object

Dim imageFileName As String

wiaManager = New WiaClass ' create COM instance of WIA manager

wiaDevs = wiaManager.Devi ces '

wiaDevs = wiaManager.Devi ces ' as CollectionClass ; ' call Wia.Devices to get
all devices

If wiaDevs Is Nothing OrElse wiaDevs.Count = 0 Then

MessageBox.Show ("No WIA devices found!", "WIA", MessageBoxButto ns.OK,
MessageBoxIcon. Stop)

Application.Exi t()

Return Nothing

End If

Dim selectUsingUI As Object = System.Reflecti on.Missing.Valu e ' = Nothing

wiaRoot = CType(wiaManage r.Create(select UsingUI), ItemClass) ' Display form
to let the user select device

If wiaRoot Is Nothing Then ' nothing to do

Return Nothing

End If

wiaPics = wiaRoot.GetItem sFromUI(WiaFlag .SingleImage,
WiaIntent.Image TypeColor) 'Open acquisition form to get a single image.

If wiaPics Is Nothing Then

Return Nothing

End If

Dim wiaObj As Object = wiaPics.Item(0)

wiaItem = CType(Marshal.C reateWrapperOfT ype(wiaObj, GetType(ItemCla ss)),
ItemClass)

imageFileName = Path.GetTempFil eName() ' create temporary file for image

wiaItem.Transfe r(imageFileName , False) ' Now do the scan and then transfer
picture to our temporary file (only way to get it)

Dim zz As Image = Image.FromFile( imageFileName) ' create Image instance from
file

AcquireScanner = zz.Clone

zz.Dispose() 'Unlock the file

zz = Nothing

File.Delete(ima geFileName)

When I get the image from the file the file remains locked so the Delete fails with a "used by another process" So I tried using a clone and disposing the obtained image. But that didn't fix the problem. Can you help?

[**Developer**]

Thanks, please see reply I just sent Lucky's first post
"Herfried K. Wagner [MVP]" <hi************ ***@gmx.at> wrote in message
news:ue******** ******@TK2MSFTN GP11.phx.gbl...

" **Developer**" <RE************ *@a-znet.com> schrieb:

When I get the image from the file the file remains locked so the Delete
fails with a "used by another process"

Check out the code snippets at
<URL:http://dotnet.mvps.org/dotnet/code/graphics/#ImageNoLock>.

--
M S Herfried K. Wagner
M V P <URL:http://dotnet.mvps.org/>
V B <URL:http://classicvb.org/petition/>

[**Developer**]

What is the penalty for not deleting a temp file?

Is that a way to go?

"Herfried K. Wagner [MVP]" <hi************ ***@gmx.at> wrote in message
news:ue******** ******@TK2MSFTN GP11.phx.gbl...

" **Developer**" <RE************ *@a-znet.com> schrieb:

When I get the image from the file the file remains locked so the Delete
fails with a "used by another process"

Check out the code snippets at
<URL:http://dotnet.mvps.org/dotnet/code/graphics/#ImageNoLock>.

--
M S Herfried K. Wagner
M V P <URL:http://dotnet.mvps.org/>
V B <URL:http://classicvb.org/petition/>