Posts

Showing posts from 2017

Some good posts about .Net and C#

What goes where in .Net Variant types in .net

Custom ComboBox control to defer current selection

I had this weird requirement in my project where: When I change the selection, new value should be sent to ViewModel, but the selection should not be changed until Success response comes back from a custom device attached to the application. i.e. If failure arrives then, combobox value will remain unchanged, and if success arrives then only ComboBox reflects the new value. Requirement was very unusual and that was not the functionality a built in combo-box supposed to do. So, I had to create a custom control with few hacks to make it work. Following is the code: public class ExtendedComboBox : ComboBox, ICommandSource { private bool _valueUpdatedFromUI; private int _previousIndex; private bool _dropDownClosed; private object _newlySelectedItem; #region DP /// <summary> /// Sends new value to ViewModel property /// </summary> public object DeferredSelectedItem { get { return (object)GetValue(DeferredSelectedItemProperty); }

Using Shared Components In Xamarin Forms

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Xamarin has several cross-platform libraries available for you to use so that we have unified API for accessing platform specific features from iOS, Windows Phone, and Android. These are all open source and available via GitHub which you can then use or modify to whatever you like. There are several components that Xamarin supports. The first is "Xamarin Social" which provides some social networking capabilities to your application. It has support for posting to Facebook and Twitter, to name a few. We also have Xamarin.Auth which is used for OAuth. It supports securely connecting to the web services. And then, we have the Xamarin.Mobile component which has Location, Camera, and Photo access. As an example, here, we have some code to take a picture using Xamarin.Mobile. This code works on iOS, Android, as well as Windows apps. The media picker that you see here provides access to the photo as a file or as a stream. So then, you can load it into whatever the platfo

From XAML to Xamarin

Recently I started exploring Xamarin Cross-platform framework ( Xamarin.Forms ) to develop apps for Android, iOS and UWP. There are couple of frameworks for doing cross-platform mobile app development, however,  as I am dominantly a C#/WPF developer, I chose Xamarin.Forms. This decision turned out to be the best decision, mainly because I had vast experience using Xaml and C# and saved 80% of my learning time. It was a great experience with Visual Studio integration of Xamarin and It took only 4-5 days to get acquainted with Xamarin. I will soon be uploading my app on Play stores, but first let me share the Pros and Cons I found: Advantages: Xamarin & .NET are very well architectures. C# is a fantastic language. Being able to use C# to develop on not just one, but 3 platforms. Since 2017, its completely Free. Xamarin allows to take my knowledge of C# and apply this to the iPhone and then Android. Can use existing c#/.net knowledge in iOS and Android. I