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Se siete interessati ecco il link: http://goo.gl/SDV354

Community Days 2014

Organized by Italian community and user group devoted to Microsoft products and technologies, to offer study days in the form of technical conferences.

Calling a WCF service through a proxy server.

C# .NET Framework 4.0

I have an application client that calls a WCF service and in this client uses a proxy for the internet connection, so when I call my service I must first provide the proxy authentication.

I have created a class that implements the IWebProxy interface:

namespace Utililty {

   public class ProxyConfig : IWebProxy {

        public ICredentials Credentials {

            get

            {

                using (var context = new AOEntities())

                {

                    var query =

                        from data in context.ConnectionParameters

                        where data.ServerName.Equals("Proxy")

                        select data;

                    if (query.Any())

                    {

                        var parameters = query.FirstOrDefault();

                        if (parameters != null) return new NetworkCredential(parameters.UserName, parameters.Password);

                    }

                    return null;

                }               

            }

            set { }

        }

        public Uri GetProxy(Uri destination) {

            return WebRequest.GetSystemWebProxy().GetProxy(destination);

        }

        public bool IsBypassed(Uri host) {

            return WebRequest.GetSystemWebProxy().IsBypassed(host);

        }       

    }

}

In this example, I retrieve the credentials from a SQL Server database, but if you prefer you can put in the application configuration file.

Then in the application configuration file (app.config), I have added this section:

 <system.net>

   <defaultProxy>

     <module type=" Utililty.ProxyConfig, Utililty"/>

   </defaultProxy>

 </system.net>

and the attribute useDefaultWebProxy="true" at the WCF binding configuration.

The ProxyConfig object will have call automatically before your call to service.

Peace & Love!

Merge several TIFF images to single multipage TIFF

C# .NET Framework 4.0

In my application, I have wanted to merge and compress several TIFF images to single multipage TIFF, for this purpose I used the framework Bitmap object with EncoderParameters like explained in this link http://stackoverflow.com/questions/3478292/whats-the-recommended-tiff-compression-for-color-photos/3480411#3480411 . Unfortunately, this solution was very slow! 3’:20’’ for merging of 1420 images.

So I searched in the web and I found this awesome solution http://bitmiracle.com/libtiff/help/merge-several-tiff-images-to-single-multipage-tiff.aspx : the time for merging images has dropped to 26’’! 

That’s miracle!

WPF (MVVM) - Retrieve the Listbox SelectedItems property

C# .NET Framework 4.0 MVVM Light Toolkit

In my WPF (MVVM) application, I want to use the Listbox SelectedItems property but this property has no setter and for this reason it’s not “bindable“ to my view model.

I have tried to use the property (IsSelected) in my object and in the XAML this item container style.

<ListBox.ItemContainerStyle>

        <Style TargetType="{x:Type ListBoxItem}">

<Setter Property="IsSelected" Value="{Binding IsSelected, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" />

        </Style>

</ListBox.ItemContainerStyle>

This solution works fine if the Listbox SelectionMode property is set to Single but if the selection mode is “Extended” (SelectionMode="Extended") it doesn’t work correctly, sometimes a few items remain selected.

Finally, I found a solution that works for me. I use the MenuItem’s CommandParameter for accessing to the Listbox SelectedItems property.

Like this.

<ListBox.ContextMenu>

<ContextMenu>

                    <MenuItem Command="{Binding AddImagesSelectedCommand}" CommandParameter="{Binding PlacementTarget.SelectedItems, RelativeSource={RelativeSource AncestorType={x:Type ContextMenu}}}" Header="{Binding Source={StaticResource CustomResources}, Path=LocalizedStrings.mnuAddImagesSelected}" />

</ContextMenu>

</ListBox.ContextMenu> 

Then in the view model:

AddImagesSelectedCommand = new RelayCommand<object>(OnAddImagesSelected, CanAddImagesSelected);

private void OnAddImagesSelected(object param)

        {

            var selectedImages = ((IEnumerable)param).Cast<CaptureImage>().ToList();

     //To do something …           

        }   

private bool CanAddImagesSelected(object param)

        {

            if (param != null)

            {

                var selectedImages = ((IEnumerable) param).Cast<CaptureImage>().ToList();

                return (selectedImages != null && selectedImages.Count > 0);

            }

            return false;

        }

We must use the PlacementTarget object because the ContextMenu is not in the same part of the Visual Tree, so that is why you cannot use ElementName etc. to reference the ListBox.

See you soon for the next trick!

WPF - Zoom an image with the slider control.

C# .NET Framework 4.0

In a WPF (XAML) view I want to zoom an image using a slider control and also in this occasion the binding help me to do this with a few code rows.

<Grid>

<Grid.RowDefinitions>

             <RowDefinition Height="*"></RowDefinition>

              <RowDefinition Height="30"></RowDefinition>

       </Grid.RowDefinitions>

       <Image Grid.Row="0" Name="ImgReader" Source="Images/Exit.png" Stretch="Uniform" RenderTransformOrigin="0.5, 0.5" >

             <Image.RenderTransform>

                    <ScaleTransform ScaleX="{Binding ElementName=SliderDocument, Path=Value}" ScaleY="{Binding ElementName=SliderDocument, Path=Value}"/>

              </Image.RenderTransform>

       </Image>

       <Slider Grid.Row="1" Name="SliderDocument" VerticalAlignment="Center" Minimum="0.1" Maximum="1" />

</Grid>

It’s great!

Strange error: 'DockingManager' does not exist in XML namespace ...' - Unblock DLL

C# .NET Framework 4.0

I have had a strange error in my WPF application when I referenced an external library (Xceed.Wpf.AvalonDock.dll).

This error

 Error The tag 'DockingManager' does not exist in XML namespace 'http://avalondock.codeplex.com'. Line 41 Position 10.

 appeared at design time but not at run-time, so after a few hours I’ve founded that this was a “security error”, because Windows protects you from components downloaded from the Internet.

After that I clicked on “Unblock” and the error is missed.

Thanks Microsoft … :-|