Visual Studio 2010 / .NET 4.0 and WinForms

This week saw a major release from Microsoft: Visual Studio 2010 and .NET 4.0. There are not many feature changes from their Beta Releases. (Also see ScottGu's and Scott Hanselman's blogs).

As expected, there is nothing new in WinForms except the fact that it can make use of many new .NET 4.0 features like MEF. And of course, there will be bug fixes and performance improvements as the Group Manager of WinForms says in response to a comment in Somasegar's Blog: "We continue to invest in WinForms for .NET FX 4.  This includes the core expectation of maintaining compatibility for applications already written in WinForms, fixing bugs that developers have reported, contributing to overall developer experiences across Visual Studio, as well as perf work and some feature development."

That "some feature" he mentioned is not to be seen any where. Look at the What's New in the .NET Framework 4 article in MSDN. It doesn't even mention WinForms!

Those who are still fond of WinForms find it comforting to say that  "WPF is still growing and it need much attention unlike WinForms which is matured and used for many critical LOB applications around the world." :)

ScatterView for Windows/WPF is here!

Finally, the wait is over and Microsoft has released Surface Toolkit for Windows Touch. Now we will be able to create Windows Applications that are touch enabled and works on Windows 7 computers with touch screens. The Toolkit brings many good old Surface touch controls including the much awaited ScatterView to the Windows platform. The good thing is that tremendous research has been done by Microsoft team in the areas of user experience and usability for these controls and hence we developers can save precious time otherwise spent on developing custom touch controls.

The controls included are:
LibraryBar, LibraryContainer, LibraryStack, ScatterView, SurfaceButton, SurfaceCheckBox, SurfaceInkCanvas, SurfaceListBox, SurfaceRadioButton, SurfaceScrollViewer, SurfaceSlider, SurfaceWindow.

These touch specific controls responds to touches, stylus and mouse clicks and have many special touch features (One example is the bulging out of scroll bars when touched).

One thing that is missing from the Toolkit is a Simulator similar to the Surface Simulator to help out those developers who do not have a touch screen.  Also the applications written using these controls will now only work on Windows 7 and not on Surface. Hopefully these may change when they release the next version of Surface (Surface 2.0) based on .NET 4.0.

Microsoft Surface Toolkit for Windows Touch Beta can be downloaded from here and more details can be found at the Surface Blog.

I am a Mobile Phone Developer now!

The MIX10 Announcement from Microsoft that the Silverlight is the development platform for Windows Phone 7 series makes me and other Silverlight developers the happiest. Without any additional learning, now we are all mobile platform developers! Moreover, the tools required to develop a mobile phone application (including the simulator) is freely available now; even before the actual Windows Phone 7 mobile phone devices are out there in the market.

The excellent post from Shawn Burke says how easy it is to develop a mobile app using Silverlight by comparing it with the iPhone app development. Read it here.

He agrees that MVC pattern is fairly complex and difficult to understand when you first walk up to it.  And that is why Microsoft chose “double click, write code!” pattern for mobile development. Cool... ain't it?

MEF in .NET 4.0/Visual Studio 2010 – Simple Example

The Managed Extensibility Framework (MEF) is a new library in .NET Framework 4.0 that helps in simplifying the design of extensible applications and components. If you are developing a .NET application (WinForms, WPF, Silverlight or ASP.Net) that supports plugins (independent libraries with different functionalities), then MEF is very handy.

Let us examine the basics of MEF through a very plain example application. I am building a WinForms showroom application which will display different vehicles. I have my own vehicles to display, and the application also supports vehicles from other vendors (aka plugins). All they need to do is to stick to my contract (aka implement the interface I give) while they develop their vehicles.

Let us first define the required contract. In Visual Studio 2010 (My version is Beta 2), create a new C# class library project and name it as Showroom.Contracts. Add an interface to it as below:

namespace Showroom.Contracts
{
    public interface IVehicle
    {
        string GetVehicleDetails();
    }
}

Now let us assume that we distribute this contract (interface library) to other vendors so that they can create vehicles that will fit in our showroom. To portray this scenario add another class library project named Vehicle.Hyundai. Add Showroom.Contracts project as a reference to this project as we need to implement the contract interface. This is going to be a plugin (extension or ComposablePart in MEF terminology) and hence we need to also add a reference to the MEF library System.ComponentModel.Composition. Add a class as shown below to this project:

namespace Vehicle.Hyundai
{
    using System.ComponentModel.Composition;
    using Showroom.Contracts;

    [Export(typeof(IVehicle))]
    public class HyundaiSonata : IVehicle
    {
        string IVehicle.GetVehicleDetails()
        {
            return "Hyundai Sonata";
        }
    }
}

Notice the Export attribute. This informs MEF that this is a plugin of type IVehicle. Now let us add one more similar class:

namespace Vehicle.Hyundai
{
    using System.ComponentModel.Composition;
    using Showroom.Contracts;

    [Export(typeof(IVehicle))]
    public class HyundaiSantro : IVehicle
    {
        string IVehicle.GetVehicleDetails()
        {
            return "Hyundai Santro!";
        }
    }
}

To portray one more vendor, add another class library project named Vehicle.Maruti and add a similar class to this as well:

namespace Vehicle.Maruti
{
    using System.ComponentModel.Composition;
    using Showroom.Contracts;

    [Export(typeof(IVehicle))]
    public class MarutiSwift : IVehicle
    {
        string IVehicle.GetVehicleDetails()
        {
            return "Maruti Swift";
        }
    }
}

Now that the contract and plugins based on these contracts are ready, let us build the showroom host or shell application to display these vehicles. Add a new WinForms project to the solution named Showroom.Shell. Add a project reference to Showroom.Contracts and reference to System.ComponentModel.Composition. Add a listbox to the form and name it as uxVehicles. This will display all the vehicles we have.

Remember we have our own vehicles to display in the showroom (besides vehicles from other vendors). Let us add a new class to the project:

namespace Showroom.Shell
{
    using System.ComponentModel.Composition;
    using Showroom.Contracts;

    [Export(typeof(IVehicle))]
    public class ShowroomVehicle1: IVehicle
    {
        string IVehicle.GetVehicleDetails()
        {
            return "Showroom Vehicle Normal";
        }
    }
}

And one more similar one:

namespace Showroom.Shell
{
    using System.ComponentModel.Composition;
    using Showroom.Contracts;

    [Export(typeof(IVehicle))]
    public class ShowroomVehicle2 : IVehicle
    {
        string IVehicle.GetVehicleDetails()
        {
            return "Showroom Vehicle Special";
        }
    }
}

Note that these are also decorated with Export attribute for MEF to pick them up later. Now go to the source code of Form1 to build the shell logic:

namespace Showroom.Shell
{
    using System;
    using System.Collections.Generic;
    using System.ComponentModel.Composition;
    using System.ComponentModel.Composition.Hosting;
    using System.Reflection;
    using System.Windows.Forms;
    using Showroom.Contracts;

    public partial class Form1 : Form
    {
        [ImportMany(typeof(IVehicle))]
        public List<IVehicle> Vehicles { get; set; }

        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            this.Vehicles = new List<IVehicle>();

            AggregateCatalog cat = new AggregateCatalog();
            cat.Catalogs.Add(new AssemblyCatalog(Assembly.GetExecutingAssembly()));
            cat.Catalogs.Add(new DirectoryCatalog("Plugins"));

            CompositionContainer contnr = new CompositionContainer(cat);

            contnr.ComposeParts(this);

            foreach (IVehicle item in this.Vehicles)
            {
                uxVehicles.Items.Add(item.GetVehicleDetails());
            }
        }
    }
}

We have declared a property named Vehicles to contain all the vehicles we plan to display in our showroom. Notice the ‘ImportMany’ attribute. It tells MEF that this property need to be loaded using plugins of type ‘IVehicle’. We have used ‘ImportMany’ as there are more than one vehicle and will be using ‘Import’ instead if there is only one plugin.

MEF's core is comprised of a catalog and a CompositionContainer. A catalog is responsible for discovering extensions (plugins) and the container coordinates creation and satisfies dependencies. The AssemblyCatalog gathers plugins from an assembly. Here we have asked it to find all the plugins (classes with ‘Export’ attributes) from the currently executing assembly (Showroom.Shell). The DirectoryCatalog gathers plugins from a directory. Here we have asked the catalog to look in a directory named ‘Plugins’ for the assemblies containing classes that have ‘Export’ attribute. We have used AggregateCatalog to aggregate the tow different (Assembly and Directory) catalogs of plugins into one. The ComposeParts method of the CompositionContainer does all the magic by importing the required types from these plugins and loading them to the corresponding properties. Here in our code, the property ‘Vehicles’ will now be loaded with all the available vehicle plugins and we call their ‘GetVehicleDetails’ methods to add the results to a the listbox.


Before running this application, copy the plugin assemblies (Vehicle.Hyundai.dll and Vehicle.Maruti.dll) to a folder named ‘Plugins’ under ..\bin\Debug\ folder of the Showroom.Shell project.

Download the complete sample (works in Visual Studio 2010 Beta 2) from here http://wayfarer.bizhat.com/techbites/downloads/mef_showroom1.zip

Visual Studio 2010 and .NET 4.0 Features

I started working in Visual Studio since its early Visual Basic days. The latest in that series was 6.0.  Then came a series of .NET platform versions: Visual Studio .NET (Rainier, 2003-Feb),  Visual Studio .NET 2003 (Everett, 2003-Apr), Visual Studio 2005 (Whidbey, 2005-Oct) and Visual Studio 2008 (Orcas, 2007-Nov). The latest version of Microsoft Visual Studio is VS 2010 (Code Name: Hawaii) and is expected to be available for public in March, 2010. I tried out the recently released Beta 2 version of VS 2010 and its cool.


Here are some of the new features (collected from various blogs including ScottGu's Blog and Kevin McNeish's Blog):
Visual Studio

• Fresh look and feel with a blue based new logo and color theme.
• Works side by side with VS 2008 and supports Multi Targeting (.NET 2.0, 3.0, ...).
• New Product Lineup (Express, Professional, Premium, Ultimate).
• Multi-Monitor Support (editors, designers and tool-windows).
• Silverlight UI layout support.
• Data binding support for both WPF and Silverlight.
• Zoom in/out of any code editing window or text editing window.
• Call hierarchy for C# is available at design time (Similar to stack trace; Right click on a symbol(method or class, etc.) and choose View Call Hierarchy).
• Naviagate To (Edit > Navigate To or Ctrl+Comma) option to do quick search for a symbol or file in the source code (can search part of a name or abbreviation like IC for InitializeComponent, and can specify multiple strings separated by space).
• Highlight References: Put the cursor on a symbol and after a short delay, all its references are highlighted. Or use Find all references (Right click on a symbol and choose Find All References) to see all its instances.(Ctrl-Shift-up/down arrow to cycle)
• Consume First Development: Even if there is no class by name Person, you can type Person obj = new Person(); and then choose to generate the class. (Ctrl+ Dot)
• Tools > Extension Manager to manage add-ins.

.NET Framework 4.0

• Dynamic Language Support. [kind of late binding: dynamic Car = GetCar();]
• MEF (Managed Extensibility Framework) for developing applications that supports plugins.
• Optional Parameters [Supply a default value to make it optional: public void CreateBook(string title="No Title", string isbn = "0-00000-000-0"){}]
• Named Parameters [Supply parameter values in any order specifying its name: CreateBook(isbn: "5-55555-5555-5"); or CreateBook("Book Title", isbn: "5-55555-5555-5");]
• Co-variance and Contra-variance support [IEnumerable<string> strings = GetStrings();IEnumerable<object> objects = strings; is now possible.]

ASP.NET 4.0

• Starter Project Templates (Installed & Online; Empty, Normal, MVC, Ajax, etc.).
• Clean Web.Config Files.
• Code Optimized Web Development Profile(Or Tools>Options>HTML Designer>Off Designer)
• ASP.NET, HTML, JavaScript Snippet Support.
• Auto start: Only on IIS 7.5 (well-defined approach to perform expensive application startup).
• URL Routing with ASP.NET 4 Web Forms.

WPF 4.0

• New controls: DataGrid, DatePicker, and Calendar
• Bag O’ Tricks controls: AnimatingTilePanel, ColorPicker, InfoTextBox, ListPager, NumericUpDown, Reveal, TransitionsPresenter, TreeMapPanel.
• Extra control: Windows 7 & Office Ribbon Control
• Graphics improvements: Cached Composition, Pixel Shader 3 Support, LayoutRounding, Animation Easing Function, CleartypeHint
• Text improvements: New Text Rendering Stack, Display-optimized character layout, explicitly selecting aliased, grayscale, or ClearType rendering modes, optimizing text hinting and snapping, support for fonts with embedded bitmaps, BindableRun (Run.Text), Custom Dictionaries, Selection and Caret Brush
• Windows 7 Multitouch Support: Multi-touch Manipulation, Inertia (Pan, Zoom, Rotate) events on UIElement, Raw multi-touch events (Up, Move, Down) on UIElement, UIElement3D and ContentElement, Multiple capture supporting multiple active controls, ScrollViewer enhancement to support multi-touch panning, Touch device extensibility, Future Surface SDK compatibility
• Windows 7 Shell Integration: Jump List (Tasks, Items, Recent and Frequent Lists) and Taskbar (Progress bar, Overlay Icon, Thumbnail buttons with commanding support, Description Text) integration
• Fundamentals: New XAML/BAML Parser Engine, Data Binding Support for DLR, Visual State Manager (VSM), HTML-XBAP Script Interop, UIAutomation Virtualization, SynchronizedInput Pattern
• Deployment: .NET Framework 4 Client Profile, Full Trust XBAP Deployment

Win Forms 4.0

• No new features or controls!
• Will maintain compatibility for applications already written in WinForms.
• Bug fixes and perf improvements.