The example
I wrote this example in an effort to monitor the Windows Services that are installed on my system at any given time. I decided to kill two birds with one stone and learn a bit about MVVM, DataBinding, and WPF in the process. I'll start by showing you a class diagram of the solution. I'll follow with providing all of the source code snippets for your review. Finally, I'll explain the application and provide a link for you to download the complete solution.
Malware and Windows Services
I've learned that Malware as well as viruses often disguise themselves as "normal" Windows services to take advantage of automatic/delayed starting capabilities. Windows services are also an ideal place for degenerates to place their malicious code because most of your typical Windows users don't take a second look here for problems.
Windows Services
And here is a screen shot of the application that I wrote to explore the many facets of WPF databinding.
As you can see, the application simply lists all Windows service names, Display names, and their dependent services. The goal was to perform a google search when double clicking a service (you can add this if you like, it's probably about 3 lines of code). I thought I could easily google suspicious looking services to find any problematic applications.
The ServiceController[] array
The .NET framework class library contains an object that describes a Windows Service and it's called the ServiceController. I decided that I would create a wrapper around this ServiceContoller array with my own object so that I could implement ObservableCollection<> as well as INotifyPropertyChanged to make the collection of objects play nice with WPF's DataBinding. Here is a class diagram that illustrates the entire application.
And here's the code....
WindowsService.cs (a wrapper to ServiceController)
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Linq;
using System.Text;
namespace WindowsServiceMonitor
{
/// <summary>
/// The purpose of this class is to serve as a wrapper class to the
/// ServiceController. This class provides propertychange notification
/// to allow databinding with WPF.
/// </summary>
public class WindowsService : INotifyPropertyChanged
{
#region "private members"
private string _serviceName;
private string _displayName;
private WindowsServiceCollection _dependentServices;
#endregion
#region "INotifyPropertyChanged event"
/// <summary>
/// Facilities property change notification and WPF databinding
/// </summary>
public event PropertyChangedEventHandler PropertyChanged;
/// <summary>
/// This method is called when any property is changed
/// </summary>
/// <param name="info"></param>
protected void OnPropertyChanged(string info)
{
PropertyChangedEventHandler handler = PropertyChanged;
if (handler != null)
{
handler(this, new PropertyChangedEventArgs(info));
}
}
#endregion
#region "Public constructors"
/// <summary>
/// Overloaded constructor
/// </summary>
/// <param name="serviceName">The short name of the service</param>
/// <param name="displayName">The friendly display name of the service</param>
/// <param name="dependentServices">An observable collection of windows services</param>
public WindowsService(string serviceName, string displayName, WindowsServiceCollection dependentServices)
{
_serviceName = serviceName;
_displayName = displayName;
_dependentServices = dependentServices;
}
/// <summary>
/// Default constructor
/// </summary>
public WindowsService() { }
#endregion
#region "Public Properties"
/// <summary>
/// The short name of the service
/// </summary>
public string ServiceName
{
get { return _serviceName; }
set
{
_serviceName = value;
OnPropertyChanged("ServiceName");
}
}
/// <summary>
/// The friendly display name of the service
/// </summary>
public string DisplayName
{
get { return _displayName; }
set
{
_displayName = value;
OnPropertyChanged("DisplayName");
}
}
/// <summary>
/// An observable collection of windows services
/// </summary>
public WindowsServiceCollection DependentServices
{
get { return _dependentServices; }
set
{
_dependentServices = value;
OnPropertyChanged("DependentServices");
}
}
/// <summary>
/// override the object tostring method to return the service name
/// </summary>
/// <returns></returns>
public override string ToString()
{
return _serviceName;
}
#endregion
}
}
WindowsServiceCollection.cs (A wrapper to ServiceController[] which inherits ObservableCollection<>)
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Linq;
using System.ServiceProcess;
using System.Text;
namespace WindowsServiceMonitor
{
/// <summary>
/// A WPF friendly collection of WindowsService objects
/// </summary>
public class WindowsServiceCollection : ObservableCollection<WindowsService>
{
/// <summary>
/// Default constructor
/// </summary>
public WindowsServiceCollection() : base() { }
/// <summary>
/// Add all windows services to this collection object
/// </summary>
/// <param name="windowsServices">The current windows service</param>
public void LoadServices(ServiceController[] windowsServices)
{
try
{
//loop through each root level service dependency
foreach (ServiceController service in windowsServices)
{
//create a new WPF friendly windows service object
WindowsService windowsService;
windowsService = new WindowsService();
//Set the service properties
windowsService.ServiceName = service.ServiceName;
windowsService.DisplayName = service.DisplayName;
try
{
//recursivley build the service depdencies
WindowsServiceCollection.BuildDependentServiceHierarchy(windowsService, service.DependentServices);
}
catch (InvalidOperationException exception)
{
//I've received unable to open ___ service on the computer
//I'll use an empty catch until i research the issue.
var operationExceptionMessage = exception.Message;
}
catch (Exception exception)
{
var generalExceptionMessage = exception.Message;
}
//add the WPF friendly service to this Observable service collection
Add(windowsService);
}
}
catch (Exception ex)
{
var message = ex.Message;
}
}
/// <summary>
/// recursivley build the service depdencies
/// </summary>
/// <param name="service">the WFP friendly windows service wrapper</param>
/// <param name="dependentServices">The collection of windows service dependencies</param>
/// <returns></returns>
public static void BuildDependentServiceHierarchy(WindowsService service, ServiceController[] dependentServices)
{
//if we don't have a valid service object
if (service == null)
//alert the caller
throw new NullReferenceException("Invalid service object.");
//loop through each dependent service
foreach (ServiceController dependentService in dependentServices)
{
WindowsService dependentServiceWrapper = new WindowsService(dependentService.ServiceName, dependentService.DisplayName, new WindowsServiceCollection());
//build the current service's dependencies
WindowsServiceCollection.BuildDependentServiceHierarchy(dependentServiceWrapper, dependentService.DependentServices);
//if the depdent services collection has yet to be created
if (service.DependentServices == null)
//create a new observable collection of dependent services
service.DependentServices = new WindowsServiceCollection();
//add the depdency to the wrappers dependents collection
service.DependentServices.Add(dependentServiceWrapper);
}
}
}
}
ServiceMonitorViewModel.cs (This is the ViewModel and it basically loads all ServiceContoller classes and builds the corresponding WindowsServiceCollections and serves the data to the WPF MainWindow view via DataBinding.)
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Linq;
using System.Text;
using System.ServiceProcess;
using System.Windows.Data;
namespace WindowsServiceMonitor.ViewModels
{
public class ServiceMonitorViewModel
{
private ServiceController[] _serviceControllers;
private WindowsServiceCollection _observableServices;
public ServiceMonitorViewModel()
{
this.LoadSystemServices();
this.ObservableWindowsServices = new WindowsServiceCollection();
this.ObservableWindowsServices = _observableServices;
//this.ObservableWindowsServices.Source = _observableServices;
}
public WindowsServiceCollection ObservableWindowsServices { get; set; }
private void LoadSystemServices()
{
_serviceControllers = ServiceController.GetServices();
_observableServices = new WindowsServiceCollection();
_observableServices.LoadServices(_serviceControllers);
}
}
}
And finally we have MainWindow.xaml which is our WPF view.
<Window x:Class="WindowsServiceMonitor.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:viewModel="clr-namespace:WindowsServiceMonitor.ViewModels"
Title="MainWindow" SizeToContent="WidthAndHeight"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008" mc:Ignorable="d">
<Window.Resources>
<viewModel:ServiceMonitorViewModel x:Key="WindosServicesViewModel"/>
<Style TargetType="ListBoxItem">
<Setter Property="FontFamily" Value="Verdana" />
<Setter Property="FontSize" Value="12"></Setter>
<Setter Property="Padding" Value="10"></Setter>
</Style>
<DataTemplate x:Key="DetailTemplate">
<Border Margin="20"
BorderBrush="Aqua" BorderThickness="1" Padding="8">
<Grid ScrollViewer.CanContentScroll="True" ScrollViewer.HorizontalScrollBarVisibility="Auto"
ScrollViewer.VerticalScrollBarVisibility="Auto" VerticalAlignment="Stretch" HorizontalAlignment="Stretch" >
<Grid.RowDefinitions>
<RowDefinition/>
<RowDefinition/>
<RowDefinition/>
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition/>
<ColumnDefinition/>
</Grid.ColumnDefinitions>
<TextBlock Grid.Row="0" Grid.Column="0" Text="Service Name:"/>
<TextBlock Grid.Row="0" Grid.Column="1" Text="{Binding Path=ServiceName}"/>
<TextBlock Grid.Row="1" Grid.Column="0" Text="Display Name:"/>
<TextBlock Grid.Row="1" Grid.Column="1" Text="{Binding Path=DisplayName}"/>
<TextBlock Grid.Row="2" Grid.Column="0" Text="Dependents:"/>
<ListBox Name="lstDependentServices" Grid.Row="2" Grid.Column="1" IsSynchronizedWithCurrentItem="True" ItemsSource="{Binding Path=DependentServices}" DisplayMemberPath="DisplayName" />
</Grid>
</Border>
</DataTemplate>
</Window.Resources>
<DockPanel>
<StackPanel>
<TextBlock>Windows Services</TextBlock>
<ListBox Name="lstServices" HorizontalAlignment="Stretch" Height="300" HorizontalContentAlignment="Stretch" VerticalContentAlignment="Center" VerticalAlignment="Stretch" DataContext="{Binding Source={StaticResource WindosServicesViewModel}}" ScrollViewer.VerticalScrollBarVisibility="Auto" IsSynchronizedWithCurrentItem="True"
ItemsSource="{Binding ObservableWindowsServices}"/>
<TextBlock Grid.Row="0" Grid.Column="0" Text="Service Properties" />
<ContentControl DataContext="{Binding Source={StaticResource WindosServicesViewModel}}" Content="{Binding ObservableWindowsServices}"
ContentTemplate="{StaticResource DetailTemplate}" />
</StackPanel>
</DockPanel>
</Window>
And that about wraps it up. Please note that each WindowsServiceCollection contains a WindowsServiceCollection of dependent windows services. Also notice the many different uses of WPF databinding. We bind the root level WindowsServiceCollection to a ListView and we bind some TextBlocks to it's selection so that way when the user clicks to select a service, we can display a details view of the specified service.
That's pretty much all there is to it. I can say that I learned a lot by writing this application and I had a lot of fun as well.
Here is a link to the entire solution for you to download WindowsServiceMonitor.zip (2.92 mb)
I hope you have enjoyed this post and I hope you will check back soon!
Thanks!
~/Buddy James
