Android UI Components and Notifications

There are two way to declare the duration of the Toast:
int dur=Toast.LENGTH_SHORT;
int dur=Toast.LENGTH_LONG;

The Toasts class is used to give a simple message that is flashed on the screen for a short time (5 to 10 seconds). A toast is the most basic and least intrusive notification.

To create a dialog, extend the DialogFragment class and implement either onCreateView or onCreateDialog method.

To avoid creating anonymous classes for click handling, you can Implement the click interfaces in your activity and pass in this when registering a click listener.

A long press is triggered when the user taps and holds on the screen. Long Presses are handled by registering an onLongPressListener.Other than the name, the setup of a long press listener is exactly the same a standard click listener.

Android 3.0 introduced the Notification. Builder class for creating notification. This builder class replaces the existing constructor for the Notification class and makes creating notifications easier.

When the user taps the screen, a touch event is fired and the corresponding onTouch method of the tapped view is called.

The process of converting a layout XML file into a hierarchy of views is called inflating. This is done using the layoutInflater class.

Like all other Android layouts, menus can be defined using XML or Java code. But it is better to use XML because we can quickly create the menu options and their order without any boilerplate code.

The correct code for Notification is as follows:
int icon=R.drawable.icon;
CharSequence ticker = “Hello World”;
Long cur=System.currentTimeMillis();
Notification notn=new Notification(icon,ticker,cur)

The onCreateOptionsMenu callback is called when the user presses the menu button; this is where we create the menu by using the layout resource file.

Context menus work the same way as options menus but are triggered when the user long presses a view.

Both statements are correct. By extending the  DialogFragment  class and implementing on onCreateView or onCreateDialog method, you can create the dialog. You can use onCreateView to set the view hierarchy for the dialog and onCreateDialog to create a completely custom dialog.