Friday, December 30, 2016

Last blog post of 2016

This is my last blog of year 2016. I just want to take a minute to say thank you to all my readers who reads my blog. It’s prodigious erudition with you all.

I wish you all a very Happy New Year and a great beginning. Catch you all in next year with same zeal :) 

Tuesday, December 27, 2016

AccessKey not working on WPF ContentPresenter

Recently I received a query from one of my friends stating that access key is not working in his WPF project when he is using ContentPresenter. So, I thought to share a post on it as it may be helpful for other reader also. Before digging directly into the problem, first let’s see what happens when access key is set directly on the Content property of a WPF Button.

Below is my code for setting a Content on a Button:
        <Button Height="39" Width="100" Content="_Save"/>

If you will run your application with above snippet, you will notice that there is no underscore coming in front of word Save. But as soon as you press ALT key, underscore comes up. Which is an expected behavior :)
Now tweak the code a bit and instead of setting content directly on a button, do it on ContentPresenter as shown below:
        <Button Width="95" Height="34" Background="Orange">
                <ControlTemplate TargetType="Button">
                        <Rectangle Fill="{TemplateBinding Background}"/>
                        <ContentPresenter Content="{TemplateBinding Content}" HorizontalAlignment="Center" VerticalAlignment="Center"/>
Now, if you will run your application with above snippet, you will get an output in which underscore is coming at incorrect place, which is before S.

Question is how to get this underscore at proper location, below S?

No worries. A simple property RecognizesAccessKey does this for you.

  <Button Width="95" Height="34" Background="Orange">
        <ControlTemplate TargetType="Button">
            <Rectangle Fill="{TemplateBinding Background}"/> 
    <ContentPresenter RecognizesAccessKey="True" Content="{TemplateBinding Content}" HorizontalAlignment="Center" VerticalAlignment="Center"/>

And that's it, we are done. Now if you will run your application, you will see the underscore under S, which is the expected output.
Happy coding!!!

Friday, December 16, 2016

Can ASP.NET Core be chosen over ASP.NET MVC?

Nowadays one of the most popular question is ‘Can ASP.NET Core be chosen over ASP.NET MVC?’
So, to answer this question, let’s have a look at .NET architecture diagram: 

By looking at above diagram, one can easily see that .NET framework is used develop desktop Windows applications using WPF and Windows Forms and Web applications using ASP.NET MVC.

.NET Core supports UWP and ASP.NET Core libraries, in which UWP is used to create Windows 10 apps and ASP.NET Core is used to build Web applications for Windows/Linux/Mac operating systems.

Now regarding what has to be chosen and when has to be chosen, I need not to re-invent the wheel because Jeff has written a very good article on it at ‘’Should I use ASP.NET Core or MVC5?’.

Hope you find this post useful.

Tuesday, December 6, 2016

Live Unit Testing in Visual Studio 2017

Let’s have a look at one of the coolest feature of Visual studio 2017. If you will see below snapshot, there are many new icons here. 

These icons are part of cool new feature called Live unit testing in Visual Studio 2017 Enterprise.

Live Unit Testing continuously runs and displays unit test result and code coverage inside editor itself. It automatically finds and runs impacted tests for every line of code. In above diagram, Red cross indicates failed test case, Green tick indicates passed test case and Blue minus indicates the code that have no test coverage at all.

Let’s start by looking at failing test case. You can quickly navigate to failing test case by clicking on tooltip as shown below: 

And below is my test case:

At this point, I’m not really sure why this is failing. So, I’ll go ahead and debug this test
We can see here that above particular code has thrown a null reference exception.
Please note that a new exception handler has been introduced in VS 2017. Now one can see complete exception details here itself.

Now as I get to know the cause of failure, I quickly went and initialized my field in my constructor as:

As soon as I updated my code, editor is showing test case as passed. Hope you enjoyed learning new feature.

Friday, December 2, 2016

Performance and Memory tips

Two things play a very significant role in any application development, and those are application’s footprint and performance. Whenever I’m asked to work on these two tracks, I used to visit a huge list of sites to get many more ideas apart from what I already know. So, I thought, why can’t I collate all the good points and add them to my repository. At the same time, I thought of sharing those points in this blog.

Rather than making this blog post full of theory, I’m planning to make it simple by just adding the bullet points.

Uhh! Enough of gossip. Let’s get started by going through some common and important rules.
  • Create object only when it is really required
  • More the objects lesser the performance :( 
  • Grab resources, use them and release at the earliest
  • Default capacity of StringBuilder is 16. So, if you want to store less than 16 values then make sure to set the capacity.
  • Avoid unnecessary boxing and unboxing
  • Prefer lazy loading
  • Use Static variables cautiously as they will stay live throughout application life
  • Avoid using IDisposable everywhere
  • For web apps, enable server GC
  • Throw fever exceptions. Avoid using exceptions to control the program flow. Never catch exceptions that you can not handle. Use Performance Monitor to check exception count and other relevant information
  • Always implement Finally block
  • Prefer value types i.e. If structure can work then why to take class
  • Prefer AddRange() over Add() for adding multiple items to collection
  • Trim your working set. Use and load minimal and only required number of assemblies. Prefer single huge assembly rather than using multiple small assemblies
  • Prefer thread pool rather than creating a new thread for each request
  • Use For loop for string iterations rather than ForEach iterator
  • Use StringBuilder for string manipulation
  • Prefer early binding
  • Be careful while choosing .NET collections as each collection is designed for specific purpose
  • Use StringCollection class to store strings
  • Use Hashtable when frequent query is required on large number of records
  • Prefer ListDictionary as it is faster than HashTable for <10 records
  • For small data go for SortedList. For large data, go for ArrayList and then call Sort method on it.
  • Prefer arrays over collections unless you need some special functionality as they use contiguous memory arrangement and are faster
  • Avoid calling GC.Collect method because it traverse all the generations. If you have to call GC.Collect in your particular niche case, then make sure to clean finalized object also using GC.WaitForPendingFinalizers() and again call GC.Collect. This will collect all the dead objects.
  • Avoid implementing Finalize as it requires 2 GC cycle. Implement it only and only you hold unmanaged resources
  • Call GC.SuppressFinalize method inside Dispose method
  • Be cautious while using Thread.Suspend, as it may lead to deadlock due to incorrect synchronization.
  • Lock(object) is the cheapest method to perform synchronization
  • Avoid locking ‘this’ as it will lock entire object, even few of its member doesn’t require synchronization 
  • Prefer Using statement to ensure Dispose is called 
  • A very good diagram is given on MSDN which talks about few more concepts around this area: 

Hope you enjoyed reading this article. Please drop your valuable comments, so that I can improvise this list further. Happy learning !!!