[RESOLVED] Error message

[Kimmy4]

Hi guys,

I have an application that basically loops through an array of photos and displays them on screen. Now if the photos are more than 24 hours old i try to delete them. But every now and then i keep gettin a message and its the same everytime. I dont know how to stop it from happening so i was hoping somebody could help me out.

Here is the full error message:

See the end of this message for details on invoking
just-in-time (JIT) debugging instead of this dialog box.

************** Exception Text **************
System.IO.IOException: The process cannot access the file 'C:\Documents and Settings\Company\Application Data\Highway 42\Plasma Screen.net\0001451521m.gif' because it is being used by another process.
at System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath)
at System.IO.File.Delete(String path)
at plasma.Form1.cleanUp() in C:\Documents and Settings\Company\My Documents\Visual Studio 2005\Projects\Plasma - 25.10.06\plasma\Form1.vb:line 607
at plasma.Form1.tmr_Time_Tick(Object sender, EventArgs e) in C:\Documents and Settings\Company\My Documents\Visual Studio 2005\Projects\Plasma - 25.10.06\plasma\Form1.vb:line 571
at System.Windows.Forms.Timer.OnTick(EventArgs e)
at System.Windows.Forms.Timer.TimerNativeWindow.WndProc(Message& m)
at System.Windows.Forms.NativeWindow.Callback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)


************** Loaded Assemblies **************
mscorlib
Assembly Version: 2.0.0.0
Win32 Version: 2.0.50727.42 (RTM.050727-4200)
CodeBase: file:///C:/WINDOWS/Microsoft.NET/Framework/v2.0.50727/mscorlib.dll
----------------------------------------
plasma
Assembly Version: 1.0.0.0
Win32 Version: 1.0.0.0
CodeBase: file:///C:/Documents%20and%20Settings/Company/Desktop/Plasma_26_01_2007/Plasma_26_01_2007/Plasma_26_01_2007/plasma/bin/Release/plasma.exe
----------------------------------------
Microsoft.VisualBasic
Assembly Version: 8.0.0.0
Win32 Version: 8.0.50727.42 (RTM.050727-4200)
CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/Microsoft.VisualBasic/8.0.0.0__b03f5f7f11d50a3a/Microsoft.VisualBasic.dll
----------------------------------------
System
Assembly Version: 2.0.0.0
Win32 Version: 2.0.50727.42 (RTM.050727-4200)
CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/System/2.0.0.0__b77a5c561934e089/System.dll
----------------------------------------
System.Windows.Forms
Assembly Version: 2.0.0.0
Win32 Version: 2.0.50727.42 (RTM.050727-4200)
CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/System.Windows.Forms/2.0.0.0__b77a5c561934e089/System.Windows.Forms.dll
----------------------------------------
System.Drawing
Assembly Version: 2.0.0.0
Win32 Version: 2.0.50727.42 (RTM.050727-4200)
CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/System.Drawing/2.0.0.0__b03f5f7f11d50a3a/System.Drawing.dll
----------------------------------------
System.Runtime.Remoting
Assembly Version: 2.0.0.0
Win32 Version: 2.0.50727.42 (RTM.050727-4200)
CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/System.Runtime.Remoting/2.0.0.0__b77a5c561934e089/System.Runtime.Remoting.dll
----------------------------------------
System.Configuration
Assembly Version: 2.0.0.0
Win32 Version: 2.0.50727.42 (RTM.050727-4200)
CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/System.Configuration/2.0.0.0__b03f5f7f11d50a3a/System.Configuration.dll
----------------------------------------
System.Xml
Assembly Version: 2.0.0.0
Win32 Version: 2.0.50727.42 (RTM.050727-4200)
CodeBase: file:///C:/WINDOWS/assembly/GAC_MSIL/System.Xml/2.0.0.0__b77a5c561934e089/System.Xml.dll
----------------------------------------

************** JIT Debugging **************
To enable just-in-time (JIT) debugging, the .config file for this
application or computer (machine.config) must have the
jitDebugging value set in the system.windows.forms section.
The application must also be compiled with debugging
enabled.

For example:

<configuration>
<system.windows.forms jitDebugging="true" />
</configuration>

When JIT debugging is enabled, any unhandled exception
will be sent to the JIT debugger registered on the computer
rather than be handled by this dialog box.

Thanks in advance for any help

[jmcilhinney]

Let me guess, you calling Image.FromFile on that file, correct? If so then read the MSDN help topic for that method and you'll find your answer.

[Kimmy4]

No i'm not, when getting the photos to check the last accessed time to delete them i'm using IO.Directory.GetFiles, storing them in an array and then looping through the array to check the last access time.

[danasegarane]

I think this thread has some information for you Link

[Kimmy4]

Thanks, but i dont see how that is going to help me as firstly i'm not using Image.FromFile and secondly i'm not using pictureboxes to display my images. I'm using Graphics.DrawImage using GDI+

???

[danasegarane]

I think you have to display code here?

[Kimmy4]

What code do you need to see....the code to display the image or to delete the file?

[danasegarane]

It will be better if we see the coding of displaying the image and deleting the file

[Kimmy4]

This is the code that deletes the files:

[vbcode]
Dim twentyFourHours As New TimeSpan(24, 0, 0)
Dim fileNames As String() = IO.Directory.GetFiles(CACHE_DIRECTORY, "*.jpg")
Dim fileNames2 As String() = IO.Directory.GetFiles(CACHE_DIRECTORY, "*.gif")
For r As Integer = 0 To fileNames.GetUpperBound(0) Step 1
dt = File.GetLastAccessTime(fileNames(r))
If dt <= Date.Now().Subtract(twentyFourHours) Then
'Error occurs when trying to delete files at this point
File.Delete(fileNames(r))
End If
Next
For p As Integer = 0 To fileNames2.GetUpperBound(0) Step 1
dt2 = File.GetLastAccessTime(fileNames2(p))
If dt2 <= Date.Now().Subtract(twentyFourHours) Then
'Error occurs when trying to delete files at this point
File.Delete(fileNames2(p))
End If
Next

[/vbcode]

and this is the code that displays the images:

[vbcode]
Dim g As Graphics = e.Graphics 'where e is System.Windows.Forms.PaintEventArgs
g.DrawImage(arrDisplay(f).image1.bmp_Image, New Rectangle(arrDisplay(f)._point.X, arrDisplay(f)._point.Y, iNew_width, iNew_height))
[/vbcode]
where arrDisplay is the array that holds all the images and the positions on the screen they should be displayed at and iNew_width and iNew_Height are the height and width the image should be drawn at

[danasegarane]

Try placing dispose in this

Dim g As Graphics = e.Graphics 'where e is System.Windows.Forms.PaintEventArgs
g.DrawImage(arrDisplay(f).image1.bmp_Image, New Rectangle(arrDisplay(f)._point.X, arrDisplay(f)._point.Y, iNew_width, iNew_height))
g.Dispose()

[Kimmy4]

Ok i'll try that but could you just explain what difference that would make please. And would i need to put that after every g.DrawImage line because i have about 3 or 4 of them???

Thanks

[jmcilhinney]

If that last block of code is in a Paitn event handler then you certainly shouldn't be disposing it. It was created by the system and it will be disposed by the system

Presumably this:

arrDisplay(f).image1.bmp_Image

refers to a Bitmap object. How are you creating that object? Are you using the Bitmap constructor? If so it locks the file just like Image.FromFile does.

[Kimmy4]

Yes it refers to a bitmap object. I am getting the image from a downloaded xml file and inserting it into the array using the following code:

Dim att_large_loc = xml_node.ChildNodes.Item(1).InnerText
Dim large_file_name As String = Path.GetFileName(att_large_loc)
arr_xml_images(i).bmp_Image = New Bitmap(CACHE_DIRECTORY & large_file_name)

CACHE_DIRECTORY is where i am storing the images when they have been downloaded.

[jmcilhinney]

Exactly as I said before. This is from the MSDN help topic for the Bitmap(String) constructor:

The file remains locked until the Bitmap is disposed.

If you want to delete the file you have to either dispose all Image objects created from it in that way or using Image.FromFile, or else use some other method of creating the Image that doesn't lock the file.

[Kimmy4]

Ok thanks.
What other ways are there that dont lock the files?

[jmcilhinney]

You can open a FileStream, then call Image.FromStream or else use the Bitmap constructor that takes a Stream object. Once you've created the Image you close the stream and the file is unlocked.

Note that creating Images doesn't just lock files for the sake of it. There is a reason for it and if you don't keep the stream open it can cause issues under some circumstances. That's because there are situations where GDI+ goes back to the stream to read more information and, if it's closed, an exception is thrown. Try it and see. It will most likely be OK but if you get generic GDI+ errors then it's because it's trying to read the stream you closed.

[Kimmy4]

Ok thanks. I have another little question. I am soon going to be changing my program to introduce XAML to make the display more appealing to look and add a bit more 'snazzy' features to it. Now when i display images do i have to keep the advice you gave me in mind or is there anything else that i should be aware of before changing my code???

Thanks again

[jmcilhinney]

The only circumstances I'm specifically aware of this issue occurring is if you try to save the Image to another file. There may well be others too though.

I don't know a thing about XAML.

[Kimmy4]

Ok thanks for all your help.