In this section, we will modify our project and create a button which will display text upon click. After our textview that we created, we will add a button as shown below. Instead of adding the code for accessing the Web service to each project, I am going to create a new Class Library project. This class library will serve as the shared library to be used by both the iPhone and Android projects. On the solution, open Resources → layout → Main.axml file. Switch from Design View and go to the Source file and type the following lines of code to build your app.

Just like in the iPhone project, you create an instance of the MyClass class and then proceed to call its USDtoEURRate() method. The only difference is that in Android, you use the RunOnUiThread() method to display the Toast window in the main UI thread. Run the application on the AVD and you can see the exchange rate after a while (see Figure 28). Expand the Resources item and then choose Layout and you can see the Main.axml file listed (see Figure 16). The Main.axml file contains the layout for your activity. In the editor, you can drag-and-drop widgets from the Toolbox onto the design surface.

Deploying your Xamarin app on Visual Studio for Windows

First, launch Xamarin Studio and you’ll see the opening screen, as shown in Figure 2. All the programs in this tutorial have been developed using Visual C#. Therefore, you should have a good understanding of code written in C# programming language. Tutorials Point is a leading https://wizardsdev.com/en/news/new-mobile-course/ Ed Tech company striving to provide the best learning material on technical and non-technical subjects. Open MainActivity.cs file and replace the existing code with the following lines of code. Enter the URL for the Web service and click the Jump to button (see Figure 25).

Instead, whatever statements added here are reflected in Xamarin Studio automatically. Be sure to save the .xib file in Xcode and then exit Xcode. In this chapter, we will see how to create a small Android application using Xamarin. In the MainActivity.cs file, add the statements that are new, as shown in Listing 7. You can compile the Class Library project into a DLL by selecting Build | Build WebServiceAccess. By this point, you should have a good feel for developing iOS and Android apps using Xamarin.

Integrated Development Environment (IDE): Xamarin Studio

Also, ensure that the HelloiPhoneViewController.h file is selected (see Figure 7). Xamarin’s approach is to let developers create UI that are unique to each platform, and then create components that can be reused easily on another platform. Xamarin takes the middle path; it respects the uniqueness of each platform and does not force developers to create apps that look the same on all platforms. On the contrary, it encourages developers to take advantage of the features that each platform offers.

In a nutshell, Figure 1 shows how Xamarin works. You write your UI code for each specific platform-one for Android and one for an iOS device. Then write business logic that can be reused on both platforms. Fill in the rest of the fields and click the OK button. You can select it from the list of existing Android Virtual Devices and then click Start to launch it.

Building Your First Mobile App with C# .NET and Xamarin

Click the Connect button to create an IBAction for the button. Click on the New button to create a new project. For now, expand the iOS section (see Figure 3) and select iPhone. On the right-side of the dialog box, select Single View Application. A good IDE enables acceleration of any development effort.

Back in Xamarin Studio, click the Run button to test the application on the AVD that you have just created. You should see a dialog box to select a device for testing. Select the AVD that you have just launched and click OK.

Coding the Counter app

The second argument specifies the message you want to display, and the third takes in an object of type MyAlertDelegate that you have defined in the code. The use of this object is to handle the Clicked event that is fired when the pop-up is dismissed, letting you know which button was clicked. The last argument is of params type, meaning you can pass in a variable number of arguments. Here, you specify the caption of the buttons that are to be displayed in the pop-up.

Xamarin exposes all the APIs available in iOS and Android to your application as regular C# class libraries. When you are ready to compile the application for each platform, Xamarin produces an ARM binary for iOS and takes advantage of just-in-time compilation for Android. As Xamarin apps are compiled to native binary, they are able to perform without any performance degradation that you might expect from cross-compiled apps.

Filed under:

Within the MyAlertDelegate class, override the Clicked method. Here, you simply want to print a statement indicating which button was clicked. To implement the partial method, define the partial method in the HelloiPhoneViewController.cs file, as shown in Listing 2. Two of the new statements added automatically in Objective-C, which you will not use directly in Xamarin.

• Then write business logic that can be reused on both platforms.
• You can compile the Class Library project into a DLL by selecting Build | Build WebServiceAccess.
• In the MainActivity.cs file, add the statements that are new, as shown in Listing 7.
• The View window loads, and after a while, the alert view displays the exchange rate, as shown in Figure 27.
• For simplicity, you are finding the exchange rate between the US Dollars and the Euro.

However, “write once, run everywhere” also means that the app will look the same everywhere. This limited the usability of the apps, as their UI must be written to the lowest-common-denominator. But the upside of using this approach is that Web apps are relatively easy (and less expensive) to build-developers simply need to know HTML, JavaScript, and CSS. Unless you have been hiding in a cave for the past few months, you have heard of a company called Xamarin. In 2013, Xamarin announced Xamarin Studio, a tool that allows developers to build mobile applications using the C# language.