Set the Build Target option to Android 4. Click Next. Click Finish, and the project will be created for you. Click the New button and configure it as shown in Figure 1. Click Create AVD when finished.
7 Key Android Concepts
When prompted, click Launch. The emulator will start. Select the running emulator, and click OK. Plug your phone into your computer. It should install on your phone. If the Android Device chooser dialog appears, select your device from the list.
This project contains all the elements you need to build your application, and you should generally place all your work in this project. This section covers the basic structure of the project folder and where you should place your code, layouts, and resources. Folder struCture Expand the Example project folder in the Package Explorer and take a look at the project structure.
Android uses a standard Java application layout. Table 1. TABLe 1. It follows the standard Java package conventions. For example, a com. This folder contains all the resources of your app and is where you declare the layout using XML. This folder contains all layout files, images, themes, and strings. It usually contains only a single file, R. Do not edit anything in this folder. This folder contains miscellaneous files needed by your application. If your app needs a binary asset to function, place it here.
To use these files, you need to open them using the Java File application programming interfaces APIs. The manifest contains essential information about your app that the Android system needs. This includes the activites and services your app uses, the permissions it requires, any intents it responds to, and basic info like the app name. It includes all the activities your app uses, the services it provides, any database content it makes available via a content provider, and any intents it processes. The manifest is where you declare the physical hardware features your app needs to run.
Users with non-touchscreen phones would not be able to download an app that requires a touchscreen to properly function. You should strive to make your application as broadly compatible as possible.
Stay ahead with the world's most comprehensive technology and business learning platform.
List features your app uses, but use code to dynamically determine their availability and gracefully degrade the user experience in your app. The manifest is where you declare the permissions required by your app. Unlike hardware requirements, all the permissions necessary to run your application must be declared in the manifest. There are no optional permissions. Note: users are very unforgiving of applications that request overly broad permissions.
The manifest is where you declare the icons and labels used by your application. You can assign these attributes to many of the XML elements in the manifest. This is what will represent your application on the device home screen and app drawer.
- English Vocabulary Elements;
- Tackling Long-Term Global Energy Problems: The Contribution of Social Science?
- Basic Econometrics?
- Android UI Fundamentals: Develop & Design | Peachpit.
- Information Systems Development: Towards a Service Provision Society.
- Robust Image Authentication in the Presence of Noise;
You can use them on the permissions element, which displays when the user accepts your application to install. These elements are inherited by any sub-components. Lastly, the manifest is where you declare your supported Android API versions. This is also a good way to prevent your app from being installed on newer API releases that you may not have tested yet.
See Table 1. Declares the minimum API level required by your application. Devices running Android versions lower than this will not be able to install your application. Declares the version of your application you are building against. This is what determines the features available to your app. Declares the maximum SDK your application supports. Use this to prevent installation on newer devices that you may not be ready to support.
What are resources? Android uses the directory structure to separate resources for use in different device configurations. In the Hello World app, there are three drawable folders: drawable-ldpi, drawable-mdpi, and drawable-hdpi. These represent low-, medium-, and high-density resources. At runtime, the Android system will select the proper resource based on the device hardware.
If no resource matches, it will select the most closely matching resource. This will be covered in depth in Chapter 3. You should place all colors, dimensions, styles, and strings in this folder. In the example Hello World app, there is a single strings. You should never use string literals in your Java code or XML layouts. Always declare any user-visible strings in the strings. This makes it easier to localize your resources later. When using these strings in your app, you reference them by the name attribute of the string element.https://europeschool.com.ua/profiles/pyfoteja/chat-para-mormones-solteros.php
UI Design Do’s and Don’ts - Apple Developer
Folder names are used to separate layouts for different device configurations. The user interface UI is the connection between your app and your users. In fact, to the user, the UI is the app. The Android UI framework is powerful enough to create complex UIs with graphics and animations, but it also has enough flexibility to scale from small-screen handheld devices to tablets to TVs. This section covers the basics of Android UI development so you can start to create great UIs for your apps. The first screen an Android user encounters is the home screen Figure 1.
The home screen consists of sliding pages containing app launcher icons and widgets. You can press the launcher icons to start the corresponding applications. Widgets are like mini applications that present small chunks of data, such as weather or unread email counts. At the bottom of the screen are quick-launch icons for opening the phone dialer or email client. This also contains the launcher for the app drawer.
A key component of the Android UI is the notification tray Figure 1. You access the tray by touching the status bar at the top of the screen and sliding your finger down. Android displays a list of all notifications in the notification tray: new mail notifications, currently playing music, system status info, and any longrunning tasks such as downloads. Tapping a notification in the list typically opens the app that generated the notification.
Related Android UI Fundamentals: Develop & Design
Copyright 2019 - All Right Reserved