WPF Discussion Boards

Allonii10-Jan-09 4:58

10-Jan-09 4:58

Im trying to write a image from a database to the hard drive and then read it back to the Image Control.

Im getting the error: The process could not access .........\temp.jpg because it is being used by another process

I have a the same app in Winforms and there its simple just put Picturebox.Image.Dispose before you attempt to write over the old file. But in WPF it won't work. I have spent hours trying to figure this out, tried to dispose a lot of resources and Google. But could not find anything.

I don't want to read the picture to the memory because it uses a lot of it.

If someone could help me it would be appreciated, Thanks

my code is

if (imageStorage.Source != null)
{
imageStorage.Source = null;
}

FileStream FS1 = new FileStream("temp.jpg", FileMode.Create);
byte[] buff = (byte[])dRow[1];
FS1.Write(buff, 0, buff.Length);
FS1.Close();
FS1.Dispose();

BitmapImage image = new BitmapImage();
image.BeginInit();
image.UriSource = new Uri(Directory.GetCurrentDirectory() + "\\temp.jpg");

image.DecodePixelWidth = 200;
image.EndInit();

imageimageStorage.Source = image;

Re: Image Control problem

User 27100910-Jan-09 15:09

User 271009

10-Jan-09 15:09

Instead of writing the data to a disk file which gets locked, why not just feed the stream directly to the image.

I Googled the below code snippet, should get you going.

BitmapImage NI = new BitmapImage();<br />
Stream ImageStream = new MemoryStream(byteArray);<br />
NI.StreamSource = ImageStream;

Cheers, Karl

» CodeProject 2008 MVP, CodeProject 2009 MVP

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modified 27-Feb-21 21:01pm.

Re: Image Control problem [modified]

Allonii10-Jan-09 15:19

Allonii

10-Jan-09 15:19

"I don't want to read the picture to the memory because it uses a lot of it."

modified on Saturday, January 10, 2009 9:27 PM

Re: Image Control problem

User 27100910-Jan-09 15:25

User 271009

10-Jan-09 15:25

What does writing the file to disk get you? Is there are requirement to do this?

Is there a reason to persist the image from the database to the disk, then read disk and load into Image?

After you read the image from the database, it is in memory. That's why is suggested that solution.

Cheers, Karl

» CodeProject 2008 MVP, CodeProject 2009 MVP

My Blog | Mole's Home Page |
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modified 27-Feb-21 21:01pm.

Re: Image Control problem

Allonii10-Jan-09 15:31

Allonii

10-Jan-09 15:31

Well I have a reason: the images loaded into the memory uses a lot of memory.

reason here is the same to save memory. Its better to write the single file to the disk and keep overwriting it until the user closes the application. Then it will be deleted

Re: Image Control problem

Snufflufugus10-Jan-09 15:54

Snufflufugus

10-Jan-09 15:54

When you set the Image.ImageSource to your file, you are reading it into memory. You can read it directly into your image instead (and overwrite as needed). All writing it to a file before loading it into your image does is create the additional overhead of the File I/O operations.

Hope this helps,

Keith

Re: Image Control problem

Allonii10-Jan-09 23:07

Allonii

10-Jan-09 23:07

How im I reading it into the memory in my code?

The big problem is that If I set imageStorage.Source = null; the source is null but the picture still has a height and width which means the its still in the Image Control?? thats the strangest part. I think if someone would suggest a solution here, it would work.

Allonii

Re: Image Control problem

Gideon Engelberth12-Jan-09 3:35

Gideon Engelberth

12-Jan-09 3:35

You are reading the picture into memory when you set the image source equal to the file. If the program is going to display the image, it MUST read the image into memory at some point and WILL keep it in memory for at least the duration of the time it is being shown.

Re: Image Control problem

Allonii12-Jan-09 23:32

Allonii

12-Jan-09 23:32

yes, I'm aware of that but its then referring to the file and by that reduce the memory usage.

I tried to write 10 pictures to the hard drive and read from them and compered the same application but instead reading from a memory stream. Well the app reading from the files used 30-50 % less memory.

That's why I don't see anything positive with reading pictures directly from a memory stream

How to pass parameters to WPF ?

Yanshof10-Jan-09 4:10

Yanshof

10-Jan-09 4:10

Im new in the WPF issues.

I create some WPF object - this object is some square that need to be in some size.
In run time i need to pass somehow the size of the square and i dont know how to do it.

thanks for any help.

Re: How to pass parameters to WPF ?

Mohammad Dayyan10-Jan-09 11:58

Mohammad Dayyan

10-Jan-09 11:58

Please post your XAML code

Re: How to pass parameters to WPF ?

Mark Salsbery12-Jan-09 8:37

Mark Salsbery

12-Jan-09 8:37

Yanshof wrote:
I create some WPF object - this object is some square

It would really make it easier to help if you specify the class of the "some WPF object".

Mark

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Re: How to pass parameters to WPF ?

Pete O'Hanlon12-Jan-09 9:31

Pete O'Hanlon

12-Jan-09 9:31

SomeWpfObject, it implements ISomeWpfObject.

"WPF has many lovers. It's a veritable porn star!" - Josh Smith

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Re: How to pass parameters to WPF ?

Mark Salsbery12-Jan-09 10:30

Mark Salsbery

12-Jan-09 10:30

I need to read the docs more closely Sigh | :sigh:

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Re: How to pass parameters to WPF ?

schiebel-t2-Feb-09 8:20

schiebel-t

2-Feb-09 8:20

Hi,
if your squar is any UIElement or a rectangle try this

Rectangle myrect = new Rectangle;
myrect.width = 10;
myrect.height = 10;
myrect.Margin = new Thickness(100,100,0,0);

Can I use a silverlight control inside my asp.net 2.0 web application?

Nada Adel10-Jan-09 3:33

Nada Adel

10-Jan-09 3:33

if I created a silverlight menu using expression blend, what do I need to do exactly in order to add to my asp.net 2.0 web application?
I know that silverlight needs framerwork 3.0 or 3.5. But my web applcation is built on framework 2.0 so how can I convert it so that I could use the silverlight control?

I need steps please..
thanks in advance

Re: Can I use a silverlight control inside my asp.net 2.0 web application?

Mark Salsbery15-Jan-09 9:15

Mark Salsbery

15-Jan-09 9:15

I don't see any reason it wouldn't work, but you do have some options:

Integrating Silverlight with a Web Page[^]

Try it!

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Issue with binding and ValidationRules

Rohde9-Jan-09 23:24

Rohde

9-Jan-09 23:24

I have a problem with ValidationRules. Basically the data binding works, but the Validate-method of the ValidationRules never fire.

This is part of my XAML (ZoomDialogBox.xaml):

<StackPanel Grid.Column="0" Grid.Row="1" Orientation="Horizontal" VerticalAlignment="Center">
            <Label>Factor:</Label>
            <TextBox Name="FactorTextBox" Width="30" Margin="10,0,0,0">
                <TextBox.Text>
                    <Binding Path="." UpdateSourceTrigger="PropertyChanged">
                        <Binding.ValidationRules>
                            <validators:ZoomFactorValidationRule MinZoomFactor="1" MaxZoomFactor="20" />
                        </Binding.ValidationRules>                        
                    </Binding>
                </TextBox.Text>
            </TextBox>
        </StackPanel>

This is the property I am binding to, and this binding works (from ZoomDialogBox.cs):

public int ZoomFactor
        {
            get
            {
                return (int) this.DataContext;
            }

            set
            {
                this.DataContext = value;
            }
        }

As said, the binding works, but the ValidationRules is never applied. What am I doing wrong here?

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Re: Issue with binding and ValidationRules

User 27100910-Jan-09 15:02

User 271009

10-Jan-09 15:02

Give this short article a read. Your missing the NotifyOnValidationError property setting.

http://blog.spencen.com/2007/10/04/wpf-validation-rules.aspx[^]

Cheers, Karl

» CodeProject 2008 MVP, CodeProject 2009 MVP

My Blog | Mole's Home Page |
XAML Power Toys Home Page

Just a grain of sand on the worlds beaches.

modified 27-Feb-21 21:01pm.

Re: Issue with binding and ValidationRules

Rohde10-Jan-09 15:34

Rohde

10-Jan-09 15:34

I did try that earlier (and now again), and the result is the same. Validate() never fires!

Re: Issue with binding and ValidationRules

User 27100910-Jan-09 15:41

User 271009

10-Jan-09 15:41

Your ZoomFactor property should be turned into a property with a backing field.

There are many different ways for the TextBox to bind to the ZoomFactor property.

One way is in the constructor of the ZoomDialogBox.cs file, use this line of code

this.DataContext = this;

Then change the Path in the TextBox to ZoomFactor.

You should also look at the VS Output window to see any data binding errors when your application is running.

Cheers, Karl

» CodeProject 2008 MVP, CodeProject 2009 MVP

My Blog | Mole's Home Page |
XAML Power Toys Home Page

Just a grain of sand on the worlds beaches.

modified 27-Feb-21 21:01pm.

Re: Issue with binding and ValidationRules

Rohde10-Jan-09 15:47

Rohde

10-Jan-09 15:47

Yes, yes yes! Thank you. Now it works. Smile | :)

And thanks for the tip on the Output window, I did not know that databinding errors was shown there. That can be a great time-saver.

Once again, thanks for the help.

Re: Issue with binding and ValidationRules

User 27100910-Jan-09 15:48

User 271009

10-Jan-09 15:48

Glad you're up and running. Have a great day!

Cheers, Karl

» CodeProject 2008 MVP, CodeProject 2009 MVP

My Blog | Mole's Home Page |
XAML Power Toys Home Page

Just a grain of sand on the worlds beaches.

modified 27-Feb-21 21:01pm.

Silverlight problem in IIS

CrazyCoder269-Jan-09 20:29

CrazyCoder26

9-Jan-09 20:29

Hi I have developed an ASP.Net application which uses silverlight.
This application works fine on my local PC.But when I uploaded it on the web server,it throws an exception saying
Silverlight error code: 2104 error type : InitializeError.
I have added the required(.xap application/x-silverlight-app,.xaml application/xaml+xml, .xbap application/x-ms-xbap ) MIME types to the IIS.
Still it is showing the same error.
Can anyone tell me how can I configure the webserver to support silverlight?
Thanks and regards

ARINDAM

Re: Silverlight problem in IIS

Mohammad Dayyan20-Jan-09 19:57

Mohammad Dayyan

20-Jan-09 19:57

I think the server doesn't support SilverLight.
Are u sure about it.

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