Don't worry. Not everyone knows it...

Most of us might be aware that Microsoft is going to rename it's one of the cloud storage service SkyDrive soon due to disputes with one of the UK firm named  British Sky Broadcasting Group. You can find this official announcement at blog by Ryan Gavin.

Nowadays MVVM is one of the most common architectural structure and hope most of us working on WPF, Silverlight, Windows Phone or Windows Store apps might have come across this. When talking about MVVM, the first thing which strikes in mind is INotifyPropertyChanged interface. The usual and most common practice of implementing INotifyPropertyChanged is: public class ViewModelBase : INotifyPropertyChanged     {         public event PropertyChangedEventHandler PropertyChanged;         protected void RaisePropertyChanged(string prop)         {             if (PropertyChanged != null)             {                 PropertyChanged(this, new PropertyChangedEventArgs(prop));             }         }     } What do you think about the above code? In first sight, it looks correct, but is it really perfect or thread safe? Well, here answer is NO. One very minor thing is missing in above code which can lead your application to crash in multi-threaded environment. If you will inspec

In continuation to my previous article titled ' Dynamically selecting DataTemplate for WPF ListView ', in this article, I am discussing about the alternative way to achieve the same goal. But here, to make the example simple, I am going to display only Employee names as shown below: Now this to achieve this, I am going to inherit MarkupExtension class provided by Microsoft. This class will give me the DataTemplate. If you will explore further, you will came to know that this MarkupExtension class has only one method named as ProvideValue, which will return me the appropriate template based on the supplied value.  Before inheriting MarkupExtension, I created a class named MyDataTemplateDictionary, which will inherit Dictionary<object, DataTemplate>. Please note, here key will be my DataTemplate name and value will be the DataTemplate. Below is the code depicting the same: Next comes is the class inheriting MarkupExtension. As there is nothing

Recently I get a chance to work on a project in which requirement was to select different different types of data templates based on the data. I faced bit difficulty, but afterwards I was manage to get it work. Let's have a look at the scenario first: Inside a WPF ListView, there are two GridViewColumns for storing Name and Age. Now requirement is to highlight the name of the person based on certain age criteria. If age is below 25, then name should be highlighted as red else it should be in green color, with desired background. I know there are ways to implement this using the concept of triggers, but I personally refrain from using triggers due to performance fall back. So, what else ??? The option left was dynamically selecting data templates. In this post I am going to write about the simplest approach and later on I'll do the same thing using Dictionary. Well, let's begin with our code. First of all, I created a class named Employee and added some data which w

Recently I was working on a XAML based application, in which my requirement was to play a sound (.wav file) whenever a given button is clicked. So, to achieve this, I wrote a below snippet: My above snippet worked but at the same time, I feel a noticeable delay in beep sound and that make me analyze further and write a blog post :) Now question is, why there is delay between button click and sound ??? Well, there is a simple concept behind it, which I missed while implementing above requirement :( Reason is, the event hierarchy.  Most of us might be aware that Click is a bubbling event, which means event will be fired from the control who initiated it. So, in our case, whenever button is clicked, it bubbles from button to window. And that's the reason, click event handler is executing before the window event is triggered, which is ultimately leading to delay. Now, how to handle this??? Method 1: Then I thought to write a preview event, which will be fired

DataTemplate is a very powerful concept which allows you to provide a visualization for your objects in your application. DataTemplate objects are very useful specially dealing with collections. If you bind your collection with any of the ItemsControl, say ListBox then by using a DateTemplate one can change the appearance of data objects very easily. Well, now let's create a DataTemplate quickly. Let's start by creating a class called Employee: FirstName and Age will be our business objects that will reside in our application. Now we will go ahead and show the value of these objects on screen in a WPF application. For that our XAML will look like: Now looking at the code-behind: In code-behind, we have set the values for FirstName and Age with DataContext of main window. So, that XAML can bind to these values via EmployeeDetail property. At this point of time, if you will run the application, you will see: By above image yo

Recently working on one of the project, I came across an requirement of validating a TextBox in which Textbox should allow numbers only between range -999 and 0. If you will surf on internet, you will perhaps find many solutions to this problem in which developers create their own versions of TextBox either by creating a Custom/User controls or by inheriting it. But problem of this approach is - you would need to replace your TextBox definitions with your newly created TextBox. Sometimes this solution can be opted but sometimes it is not feasible to do so. This article describes on how to enhance existing WPF TextBox to make it happen. So, the approach I am proposing here doesn't require the replacement of existing TextBox control. Whilst it uses the very basic concept of Events. Well, enough of theory. Let's move on to coding part: XAML code: Code-Behind code: Hope you like this clean approach.