Tutorial by Examples: en

Say we have a button (we can create it programmatically, or bind it from a view using findViewbyId(), etc...) Button btnOK = (...) Now, create an anonymous class and set it inline. btnOk.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { ...

Declaration of an interface using the interface keyword: public interface Animal { String getSound(); // Interface methods are public by default } Override Annotation @Override public String getSound() { // Code goes here... } This forces the compiler to check that we are overri...

Collect with toList() and toSet() Elements from a Stream can be easily collected into a container by using the Stream.collect operation: System.out.println(Arrays .asList("apple", "banana", "pear", "kiwi", "orange") .stream() .filter...

Generics enable classes, interfaces, and methods to take other classes and interfaces as type parameters. This example uses generic class Param to take a single type parameter T, delimited by angle brackets (<>): public class Param<T> { private T value; public T getValue() ...

To use a NavigationView just add the dependency in the build.gradle file as described in the remarks section Then add the NavigationView in the layout <?xml version="1.0" encoding="utf-8"?> <android.support.v4.widget.DrawerLayout xmlns:android="http://schema...

Dependencies can be added for a specific product flavor, similar to how they can be added for specific build configurations. For this example, assume that we have already defined two product flavors called free and paid (more on defining flavors here). We can then add the AdMob dependency for the ...

A Java class can implement multiple interfaces. public interface NoiseMaker { String noise = "Making Noise"; // interface variables are public static final by default String makeNoise(); //interface methods are public abstract by default } public interface FoodEater { ...

This example illustrates sending a String with value as "Some data!" from OriginActivity to DestinationActivity. NOTE: This is the most straightforward way of sending data between two activities. See the example on using the starter pattern for a more robust implementation. OriginActivit...

An interface can extend another interface via the extends keyword. public interface BasicResourceService { Resource getResource(); } public interface ExtendedResourceService extends BasicResourceService { void updateResource(Resource resource); } Now a class implementing ExtendedR...

Addition Map<Integer, String> map = new HashMap<>(); map.put(1, "First element."); System.out.println(map.get(1)); Output: First element. Override Map<Integer, String> map = new HashMap<>(); map.put(1, "First element."); map.put(1, &quot...

Methods can also have generic type parameters. public class Example { // The type parameter T is scoped to the method // and is independent of type parameters of other methods. public <T> List<T> makeList(T t1, T t2) { List<T> result = new ArrayList<T&...

When we create any View in layout, we can use the android:onClick attribute to reference a method in the associated activity or fragment to handle the click events. XML Layout <Button android:id="@+id/button" ... // onClick should reference the method in your activity or fra...

Dimensions are typically stored in a resource file names dimens.xml. They are defined using a <dimen> element. res/values/dimens.xml <?xml version="1.0" encoding="utf-8"?> <resources> <dimen name="small_padding">5dp</dimen> &l...

Data model public class Item { private String name; public String getName() { return name; } } Layout XML You must import referenced classes, just as you would in Java. <?xml version="1.0" encoding="utf-8"?> <layout xmlns:android="h...

package com.example; import android.os.Bundle; import android.support.annotation.Nullable; import android.util.Log; import android.view.View; import android.view.ViewTreeObserver; public class ExampleActivity extends Activity { @Override protected void onCreate(@Nullable final ...

// Compile a Uri with the 'mailto' schema Intent emailIntent = new Intent(Intent.ACTION_SENDTO, Uri.fromParts( "mailto","[email protected]", null)); // Subject emailIntent.putExtra(Intent.EXTRA_SUBJECT, "Hello World!"); // Body of email emailIntent.putEx...

public class MyActivity extends Activity { private static final String PREFS_FILE = "NameOfYourPrefrenceFile"; // PREFS_MODE defines which apps can access the file private static final int PREFS_MODE = Context.MODE_PRIVATE; // you can use live template "key"...

If you want to take a screenshot from the Android Emulator (2.0), then you just need to press Ctrl + S or you click on the camera icon on the side bar: If you use an older version of the Android Emulator or you want to take a screenshot from a real device, then you need to click on the camera ico...

Once the SDK installed, you can open the AVD Manager from the command line using android avd. You can also access AVD Manager from Android studio using Tools > Android > AVD Manager or by clicking on the AVD Manager icon in the toolbar which is the second in the screenshot below.

It is possible to define an array with more than one dimension. Instead of being accessed by providing a single index, a multidimensional array is accessed by specifying an index for each dimension. The declaration of multidimensional array can be done by adding [] for each dimension to a regular a...