Sharing Violation on image View and Edit WPF

问题:

I'm working on MVVM and WPF application. I have a scenario in which i have to edit the viewing image and save it.

I have used RadCarousel in which using the ContextMenu on right click i'm editing the image using mspaint. When i try to save the edited image i get the "Sharing violation error on path".

The images are located in a shared folder.

//XAML Code:

    <telerik:RadCarousel x:Name="MarketSeriesCarousel" 
                             HorizontalAlignment="Stretch"
                             VerticalAlignment="Stretch" 
                             ItemsSource="{Binding Path=MarketSeriesImageList, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged, NotifyOnSourceUpdated=True, NotifyOnTargetUpdated=True}" 
                             SelectedItem="{Binding SelectedMarketSeriesImage, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged, NotifyOnSourceUpdated=True}" 
                             Background="Transparent" 
                             HorizontalScrollBarVisibility="Auto" 
                             ScrollViewer.CanContentScroll="True" 
                             ScrollViewer.VerticalScrollBarVisibility="Auto"                                                                 
                             telerik:StyleManager.Theme="Windows8" 
                             Focusable="True" 
                             PropertyChanged="MarketSeriesCarousel_PropertyChanged">
     <telerik:RadCarousel.ContextMenu>
        <ContextMenu >
            <MenuItem Header="Edit" Command="{Binding EditImage}" CommandParameter="{Binding }"/>     
            <MenuItem Header="MetaData" IsEnabled="False"/>  
            <MenuItem Header="Delete" Command="{Binding DeleteImage}"/>                         
        </ContextMenu>

    </telerik:RadCarousel.ContextMenu>     

    <telerik:RadCarousel.ItemsPanel>
        <ItemsPanelTemplate>
            <telerik:RadCarouselPanel Path="{StaticResource path}" 
                                      telerik:StyleManager.Theme="Windows8" >
            </telerik:RadCarouselPanel>
        </ItemsPanelTemplate>
    </telerik:RadCarousel.ItemsPanel>
    <i:Interaction.Triggers>
        <i:EventTrigger EventName="MouseDoubleClick">
            <i:InvokeCommandAction Command="{Binding ViewSeriesImage}" />
        </i:EventTrigger>

    </i:Interaction.Triggers>
</telerik:RadCarousel>

//ViewModel Code:

/// <summary>
        /// Edit image viewer.
        /// </summary>
        private void EditImageViewer()
        {
            try
            {

                ProcessStartInfo startInfo = new ProcessStartInfo(ImagePath);
                startInfo.Verb = "edit";
                Process proc = Process.Start(startInfo);

            }
            catch (Exception ex)
            {
                // Error handling.

                throw new ApplicationException(ex.Message);
            }
        }

Any possible ways that i can achieve this? Or any alternatives for image editing.

But i need all the functionalities in the mspaint.

回答1:

You get this error because your wpf application is keeping a the image file locked because you are actually referring to it. To solve this problem create a memory bitmap image of the same file. I use following code for this also using mvvm :

public BitmapImage Image
    {
        get
        {
            if (!image_retrieved) getImageAsync();
            return _Image;
        }
    }

private async Task getImageAsync()
    {
        image_retrieved = true;
        _Image = await ImageFactory.CreateImageAsync(ImageFullPath).ConfigureAwait(true);
        this.OnPropertyChanged(() => Image);
    }

public static async Task<BitmapImage> CreateImageAsync(string filename)
    {
        if (!string.IsNullOrEmpty(filename) && File.Exists(filename))
        {
            try
            {
                byte[] buffer = await ReadAllFileAsync(filename).ConfigureAwait(false);
                System.IO.MemoryStream ms = new System.IO.MemoryStream(buffer);
                BitmapImage image = new BitmapImage();
                image.BeginInit();
                image.CacheOption = BitmapCacheOption.OnLoad;
                image.StreamSource = ms;
                image.EndInit();
                image.Freeze();
                return image;
            }
            catch
            {
                return null;
            }
        }
        else return null;
    }

static async Task<byte[]> ReadAllFileAsync(string filename)
    {
        try
        {
            using (var file = new FileStream(filename, FileMode.Open, FileAccess.Read, FileShare.Read, 4096, true))
            {
                byte[] buff = new byte[file.Length];
                await file.ReadAsync(buff, 0, (int) file.Length).ConfigureAwait(false);
                return buff;
            }
        }
        catch
        {
            return null;
        }
    }

Then change your binding to bind to the Image property. It is doing the image creating asynchronously if you don't need that just do in your gui thread.