Android Material

1. Difference between Service and AsyncTask? 2. Life cycle of fragment? 3.  Localization in Android 4.  Handling different display devices in android 5.  How mdpi, hdpi, xhdpi folder works? 6. Custom UI design procedure? 7. Bluetooth connection and how u will pair? 8. Abstract, interface, inheritance? 9. Overloading, over riding? 10. What is thread, process, and how will u create thread? 11. What is synchronization and where will you use it? 12. Why we will go for serialization and its importance in java? 13. HashMap, hashtable, iterator, enumaration? 14. which one is best to use ArrayList or LinkedList? 15. what is ThreadLocal? 16. StoredProcedure, Sqlite 17. Difference between IntentService n service? 18. How will you create Broadcase receiver and where u used in ur project? 19.  What is a “DOCTYPE” tag and what does this tag do? 20.  How does a browser come to know, if the page written is in HTML4.1 or   HTML5 ?

1. Application Localization Process Android loads text and media resources from the project’s  ‘res’  directory. Additionally, Android can select and load resources from different directories, based on the current device configuration and locale. For example, if the code loads a string called ‘R.string.title’ , Android will choose the correct value for that string at runtime by loading the appropriate strings.xml  file from a matching  ‘res/values’  directory. In order to have a multilingual Android app you need to provide Android with the localized resource files. If the locale is  ‘en-US’ , Android will look for a value of “R.string.title”  by searching the files in the following order: ‘res/values-en-rUS/strings.xml’ ‘res/values-en/strings.xml’ ‘res/values/strings.xml’ When it manages to find the string in the resource file, it uses that value and stops searching. This means that the default language acts as a fall-back option and when translation exists, it’s used

Handling Different Device Displays Android devices come in a variety of different screen sizes and resolutions. The ideal solution is to design the user interface of your application so that it appears correctly on the widest possible range of devices. The best way to achieve this is to design the user interface using layout managers that do not rely on absolute positioning (in other words specific X and Y coordinates) such as the RelativeLayout so that views are positioned relative to both the size of the display and each other. Similarly, avoid using specific width and height properties wherever possible. When such properties are unavoidable, always use density-independent (dp) values as these are automatically scaled to match the device display at application runtime. Having designed the user interface, be sure to test it on each device on which it is intended to be supported. In the absence of the physical device hardware, use the emulator templates wherever possible to tes

Solution 1: You can create different graphic objects for use at different pixel densities. Android treats mdpi (160 pixels/inch) as the base density. So for mdpi devices, 1 dp = 1 pixel. At higher densities, there are more pixels per inch (240 for hdpi, 320 for xhdpi). Android attempts to make graphic images occupy the same physical dimensions on the screen regardless of the device pixel density. So if all it finds is an mdpi resource, and the device is hdpi, it will scale the graphic by 240/160 = 150%, and it will double the size of the graphic for xhdpi. If you don't want this automatic scaling (which can make graphics look poor), you can simply supply your own version of graphic resources for use at higher densities. These graphics should be of the same size that Android would scale an mdpi resource. Note that the pixels/inch that was stored in the image file has nothing to do with this. It's all based on where you put the graphics files in the resources directory f