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Multitouch Applications on Windows 7

Here are some good blog posts for those people who are currently doing experiments in Multitouch Applications on Windows 7:

Experimenting with Multi-Touch on Windows 7 ( Part 1 )
Experimenting with Multi-Touch on Windows 7 ( Part 2 )
Experimenting with Multi-Touch on Windows 7 ( Part 3 )
Experimenting with Multi-Touch on Windows 7 ( Part 4 )

What is Azure Service Platform?

Azure service platform is a cloud computing platform hosted in Microsoft data centers. This provides operating system & different set of development service which the developers can use to build their own web applications or enhance them directly in that platform. Without purchasing any upfront technology, developers can create their applications more quickly & easily in the cloud. They only need working knowledge in .Net Framework & Visual Studio Environment. Azure service currently supports native languages. In future it will support many more including Microsoft & Non-Microsoft languages. Once the coding is done, the developer can build & host the application in the cloud, so that end user will be able to run it over the internet.
Azure platform consists of Windows Azure, which is an Operating System to provide on demand computing, storage and management of cloud applications. In short, Windows Azure is an Operating System for the cloud computing platform designed for utility computing. It provides facilities to write, host or manage applications & store data on demand. The service layer consists of different services like: Live Service, .Net Service, SQL Service etc. which provides building blocks within the platform for the developers.

What is Cloud Computing?

Cloud computing is a dynamic style of computing in which virtualized resources are provided as a service over the internet. The users of cloud computing need not to worry about the capital expenditure and maintenance cost of hardware and software resources. They have to pay only what they are using. This can be of two types. User can either pay the provider based on the resources consumed during the time period or a time based subscription. 


The Cloud Computing services are delivered through data centers & servers with different steps of reliable virtualization technologies. These are accessible from anywhere over the world with only an internet connection as it appears as a single point of access over the net.

The main characteristics of Cloud computing is:
-  Add or Remove capacity on demand
-  Pay for what you use as you go
-  Reduce cost by implementing Automation

There are three different types of cloud computing.
- Public computing
- Private computing
- Hybrid computing

Public cloud computing is a type of computing where the providers shares the resources to the consumers dynamically via web services over the internet and bills on consumption basis.

Private cloud computing is a type of computing where the resources are shared in a private network.

Hybrid cloud computing consists of multiple public & private clouds.

Cloud computing architecture is defined as Infrastructure as a Service, Software as a Service and Platform as a Service. Infrastructure as a Service provides all the required hardware resources on terms of consumptions. User has to pay the bill based on the unit consumed during the period. So there is no need to purchase high cost servers, data center spaces or network devices. In Software as a Service providers gives an application by hosting them on their own servers to the user on demand. It actually delivers a single piece of application to multiple consumers at a time. Platform as a service delivers computing platform & solution as a service. So there is no need to buy & maintain any hardware & software for building & deploying web applications. It offers design, development, testing, deployment & hosting application throughout it's complete life cycle over the internet.

Cloud Computing is a platform which enables hosting of applications in a virtual environment over the internet. It supplies all the necessary hardware, software & storage capacity in terms of high end servers & data centers. So, there is no need to purchase or maintain those resources locally. Hence, it reduces the cost of purchasing hardware or storage space. The amount of storage space which required by the end user, has to pay only that much of amount and whenever require he can increase or decrease the amount of space to be paid. Due to its automation, no one has to worry about keeping the software's updated with all the security patches. For its flexibility over the internet, one can work from any location & can access their data from wherever they are rather than sitting on their own work-desk.

Bing – Microsoft’s new Search Engine

Microsoft launched their new search engine named Bing (Kumo) on 28th May in Europe which went fully online on 3rd June. This search engine was designed to help people not only to quickly find anything over the internet but also to plan a trip or make a purchase decision. Using "Bing" the end user can find any information they need on their daily basis to accomplish their tasks. Bing categories results in different category, based on which the user can find relevant results more accurately.


image image

You can find some Tips & Tricks on Bing.com at: http://www.labnol.org/internet/bing-tips/8931/

What is Google Wave?

Google Wave is a project announced by Google on 28th May 2009 at the Google I/O conference is expected to release later in 2009. This will be a next generation email subsystem designed to merge email, instant messaging, social networking & wiki featuring strong spelling/grammar checking & automated translation between nearly about 40 different languages.

The term "Waves" described by Google as "equal parts conversation and document", means any authorized participant can reply anywhere in the conversation, they can edit or can add more participants during the conversation process. All the participants will be notified of changes or replies in all the waves they are actively participating & all the modifications will be seen at real time, letter by letter. Not only this, multiple participants may edit a single wave simultaneously in the same context.

imageThis ability of Google Wave will let user to create collaborative documents modified in different location with full modification history, which can be searched by an user to view/modify any changes just like wikis.

More information about this is available in Google Wave Site.

What’s new in .Net 4.0 and Visual Studio 2010?

Microsoft has recently launched Visual Studio 2010 and .Net 4.0 Beta 1 with more expressive features. Some of them are mentioned below:

[New Language Support]
Visual F# is a new programming language which actually combines functional & object oriented programming to provide scalable language for .Net.

[Test Driven Development]
Visual Studio 2010 now offers greater support for test driven development where tests can be written before the actual code as an approach to the software design.

[Multi Targeting]
By using the multi targeting feature you can also create application of earlier version in new IDE of visual studio.

[Parallel Processing]
Using the new parallel extension of .Net 4.0 developers can create application which will scale efficiently as the number of cores & processors increase.

The new framework improvements & expanded capabilities in the security model by simplifying the security policy. Now runtime support has been removed for enforcing the Deny, RequestMinimum, RequestOptional, and RequestRefuse permission requests.

.Net framework 4.0 beta 1 now provides improvement in the startup time and faster performance for multi threaded applications.

[Lazy Initialization]
By using this feature, the memory for an object is not allocated until it is needed. This improves the performance by spreading the object allocation across the lifetime of the application.

[In-Process Execution]
This enables an application to load & activate multiple version of the CLR inside the same process. Now you can run applications those are based on the .Net 2.0 & .Net 4.0 inside the same process.

In the new framework you can now attach, run and detach profiling tasks at any point of time.

[Garbage Collection]
.Net Framework 4.0 now supports background garbage collection. In earlier frameworks it was a concurrent garbage collection.

[Collection & Data Structure]
- The new framework now includes BigInteger which supports all the standard numeric operation including the bit operation.
- It now supports self balancing SortedSet tree which sorts automatically after insert/delete operation.
- A new data structure named Tuple has been introduced in this framework which can hold an ordered set of heterogeneous items.

[Exception Handling]
The new CLR can now handle any exception regarding the corrupted state of the underlying operating system.

and more…

Custom Virtual Panel to hold huge data

Recently, I was facing performance issue while working with huge data. I need to bind those data inside a panel as Custom User Control & want to change the properties multiple times in a second. When I used less no's of data it was working fine, but, when I tried with more no of data, my application starts crying. It was a real pain to the application to start while loading those records & unfortunately I didn’t get any solution to that.

After doing a lot of analysis with VirtualizingStackPanel concept that I shared in my previous post “What is Virtualizing StackPanel?” didn’t solve my problem which I was facing due to huge no of data.

Later, I found a very good post (“WPF: Adventures in Virtualization by Mike Taulty”) shared by Dr. WPF on implementing custom Virtual Panel, which actually resolved my problem.

Here you will find some very good articles on step-by-step implementation of Virtual Panel:

Those are very nice articles to implement the custom virtual panel step-by-step & after implementation of this panel, I noticed a huge performance improvement in my application. This really helped me while working with a huge records.

Now, come to the basic concept of this virtual panel. What it actually does. It loads all the records in a different thread & populate them in the UI as much as records that can be viewable in the screen. While scrolling, it actually creates new object of the elements by virtualizing the existing elements. So, only those objects will be in the memory which are available in the screen. The rest will go for a cleanup process. Hence, improving the performance more & more…. depending on the visible UI elements.

See a nice example in this location: http://blogs.msdn.com/jgoldb/attachment/8116217.ashx

What is Virtualizing StackPanel?

Virtualizing StackPanel generates container items when needed & throws them from memory when they are no longer in the view. When the panel has huge number of items, at that time there is no need to keep the extra items in memory which are not in view. This solves the memory problem.

If you are populating a huge number of items in any panel, then it is a better idea to use the Virtualization. But, due to throwing away of the extra items & recreating them when in view, costs some extra processing power when the Virtualizing StackPanel uses the default Standard Mode. To solve this issue, just change the virtualization mode to "Recycling". This is called as Container Recycling, which introduced in .Net 3.5 SP1 as a new feature.

By default, this recycling mode is turned off. To enable the container recycling, first turn on the Virtualizing StackPanel with “VirtualizationModeProperty” as “Recycling”.

<WrapPanel x:Name="wrpPanel" VirtualizingStackPanel.IsVirtualizing="true" VirtualizingStackPanel.VirtualizationMode="Recycling" />

You can also use GetVirtualizationMode() & SetVirtualizationMode() to get or set the current mode.

How to Implement a DependencyProperty?

DependencyProperty is set to enable declarative code to alter the properties of an object which reduces the data requirements by providing a more powerful notification system regarding the change of data in a very specific way. In .NET, there are two types of properties. One is the normal property & another is the DependencyProperty which has added functionality over the normal property.

Now, let us discuss on how to implement such DependencyProperty to give a powerful notification on data change:

First of all, implement the UserControl class from INotifyPropertyChanged interface:

public partial class MyUserControl : UserControl, INotifyPropertyChanged
    public event PropertyChangedEventHandler PropertyChanged;
    protected void OnPropertyChanged(string propertyName)
        if (PropertyChanged != null)
            PropertyChanged(this, new PropertyChangedEventArgs(propertyName));

Create your own normal Property, lets say the name of the property is “Caption”.

public string Caption

    get { return GetValue(CaptionProperty).ToString(); } 
    set { SetValue(CaptionProperty, value); }

Now, register the DependencyProperty to the CLR by calling the Register method by passing the property field that you used to store the data in earlier step:

public static readonly DependencyProperty CaptionProperty = DependencyProperty.Register("Caption", typeof(string), typeof(MyUserControl), new PropertyMetadata(string.Empty, OnCaptionPropertyChanged));

The name of the identifier field of the DependencyProperty will be same as you used in the property after appending “Property” at the end. In this example, our Property name is “Caption”, hence our identifier field name is “CaptionProperty”. Add the PropertyMetaData with default value & callback event handler within the Register method as mentioned in the above code. Mark the identifier as static & readonly so that this will be unique to the CLR.

Now, implement the OnCaptionPropertyChanged event handler:

private static void OnCaptionPropertyChanged(DependencyObject dependencyObject, DependencyPropertyChangedEventArgs e)

    MyUserControl myUserControl = dependencyObject as MyUserControl; 

private void OnCaptionPropertyChanged(DependencyPropertyChangedEventArgs e)
    txbCaption.Text = Caption;

The implementation of the DependencyProperty is complete. You can either call it from XAML:

<local:MyUserControl Caption="My First Dependency Property Example" />

or from Code behind:

MyUserControl myUserControl = new MyUserControl();
myUserControl.SetValue(MyUserControl.CaptionProperty, "My First Dependency Property Example");

How to add a Splash Screen to WPF application?

Splash Screens are always helpful while starting the application. At the time of loading application code & data from backend, it is always good to show a splash screen to the end user. It actually gives a look & feel of loading something and that time the user will see the first UI on his desktop. In .Net 3.5 SP1, this is really simple. Just do the following to add a simple basic splash screen to your application.

1. Create a PNG image & add it to your project. PNG images are better choice rather than BMP images because, they are lighter in size and you can also create a transparent PNG image.

2. Now right click on that image & click properties from the solution explorer of Visual Studio 2008 SP1.

3. Here you will find an option named “Build Action”. Select “SplashScreen” from the dropdown.

4. Save the project, build it & run the application.

Now you will see the image (Splash Screen) before rendering the actual application. After completion of rendering of the main window, the Splash Screen will automatically close. This way, it improves the startup experience of the WPF application.

How to create SSL certificate for Web Development?

Microsoft provides a tool named “MakeCert.exe” which helps us to create a temporary SSL Certificate for development environment. This tool comes with Visual Studio & also with Windows SDK. If you installed Visual Studio, you can find it in this location: “C:\Program Files\Microsoft Visual Studio <VERSION>\SmartDevices\SDK\SDKTools”. If you installed Windows SDK, you will get it here: “C:\Program Files\Microsoft SDKs\Windows\<VERSION>\Bin”.

Now open Command Console (“cmd.exe”) & change your current directory to one of the location specified above. Type the following in Command Prompt & hit enter:

makecert -b 01/01/2009 -e 01/01/2020 -n "CN=Developers" -pe -r -sk "Microsoft Cryptographic Provider" -ss "Microsoft Cryptographic Store" c:\developerCertificate.cer

This will create a test certificate (valid from 01/01/2009 to 01/01/2020) named “developerCertificate.cer” in your ‘C’ drive, which you can use for development environment. You can change the validity period by changing the begindate (-b) & expirydate (-e). You can also change all the parameters specified above.

Here is the list of the parameters mentioned above:

Parameter Description
-b Begin Date
-e Expiry Date
-n Certificate Subject Name
-pe Mark Generated Private Key as Exportable
-r Configures MakeCert to create a self-signed root certificate
-sk Subject’s Key Container Name
-ss Subject’s Certificate Store Name

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