Learn how to handle android<android events from scratch. 24 .>

There are a number of events in Android, each of which has its own corresponding processing mechanism.

As in the following several

1	Click events	View.onclicklistener	public abstract void OnClick (View v)	Triggered when a component is clicked
2	Click events	View.onlongclicklistener	Public abstract Boolean Onlongclick (View v)	Triggered when the component is long pressed
3	Keyboard events	View.onkeylistener	Public abstract Boolean OnKey (View v, int keycode, keyevent event)	Handling Keyboard Events
4	Focus Event	View.onfocuschangelistener	public abstract void Onfocuschange (View V, boolean hasfocus)	Trigger when focus changes
5	Touch events	View.ontouchlistener	Public abstract Boolean OnTouch (View V, motionevent event)	Generate Touch Events
6	Create a context Menu	View.oncreatecontextmenulistener	public abstract void Oncreatecontextmenu (ContextMenu menu, View V, Contextmenu.contextmenuinfo menuinfo)	triggered when the context menu is created

Monitoring Methods

1	public void Setonclicklistener (View.onclicklistener l)	Ordinary	Registering Click events
2	public void Setonlongclicklistener (View.onlongclicklistener l)	Ordinary	Registering Long Press Events
3	public void Setonkeylistener (View.onkeylistener l)	Ordinary	Registering keyboard events
4	public void Setonfocuschangelistener (View.onfocuschangelistener l)	Ordinary	Register Focus Change Event
5	public void Setontouchlistener (View.ontouchlistener l)	Ordinary	Registering Touch Events
6	Public void Setoncreatecontextmenulistener (view.oncreatecontextmenulistener L)	Ordinary	Registering context Menu Events

The following is an example of an onclick stand-alone event that illustrates three ways to handle events in Android

1. Internal class handling events

2. Anonymous internal class handling events

3. Data Source Handling Events

Examples are as follows:

XML file

<span style= "FONT-SIZE:18PX;" ><relativelayout xmlns:android= "http://schemas.android.com/apk/res/android" xmlns:tools= "http// Schemas.android.com/tools "android:layout_width=" match_parent "android:layout_height=" Match_parent "Android:paddi ngbottom= "@dimen/activity_vertical_margin" android:paddingleft= "@dimen/activity_horizontal_margin" Android: paddingright= "@dimen/activity_horizontal_margin" android:paddingtop= "@dimen/activity_vertical_margin" tools: Context= ". Mainactivity "> <button android:id=" @+id/button1 "android:layout_width=" Wrap_content "Andro        id:layout_height= "Wrap_content" android:layout_alignparenttop= "true" android:layout_centerhorizontal= "true"        android:layout_margintop= "60DP" android:text= "Way One"/> <button android:id= "@+id/button2" Android:layout_width= "Wrap_content" android:layout_height= "wrap_content" android:layout_alignleft= "@+id/b Utton1 "Android:layout_below= "@+id/button1" android:layout_margintop= "44DP" android:text= "way Two"/> <Button        Android:id= "@+id/button3" android:layout_width= "wrap_content" android:layout_height= "Wrap_content" android:layout_alignleft= "@+id/button2" android:layout_below= "@+id/button2" android:layout_margintop= "35d P "android:onclick=" click "android:text=" mode three "/> </RelativeLayout></span>

Java files

<span style= "FONT-SIZE:18PX;" >package Com.example.actionoperator;import Android.app.activity;import Android.os.bundle;import Android.view.view;import Android.view.view.onclicklistener;import Android.widget.button;import Android.widget.toast;public class Mainactivity extends Activity {public Button button1, Button2, button3;// Get Bubuttononclicklistener object Buttononclicklistener click =new buttononclicklistener (); @Overrideprotected void OnCreate (Bundle savedinstancestate) {super.oncreate (savedinstancestate); Super.setcontentview (r.layout.activity_ Main); button1 = (Button) This.findviewbyid (r.id.button1); button2 = (Button) This.findviewbyid (r.id.button2); Button3 = (Button) This.findviewbyid (R.ID.BUTTON3);//Use internal classes for processing Button1.setonclicklistener (new MyListener ());// Working with anonymous inner classes Button2.setonclicklistener (new Onclicklistener () {@Overridepublic void OnClick (View arg0) {//TODO Auto-generated method Stubtoast.maketext (Mainactivity.this, "methods of anonymous internal classes to implement the method of listening processing", 2). Show ();}); /Use the data source method to process, can say all single-machine thingsRegister on this click to process Button3.setonclicklistener (click);} Class Buttononclicklistener implements Onclicklistener {public void OnClick (View v) {//reader can set the switch case statement here to the ID of the passed parameter   The same method that implements multiple events is used to process if (V==button3) {Toast.maketext (mainactivity.this, "Use data source implementation Method listener processing", 2). Show (); }}class MyListener implements Onclicklistener {@Overridepublic void OnClick (view view) {//TODO auto-generated method stub Toast.maketext (Mainactivity.this, "method implementation method for inner class listener processing", 2). Show ();}} </span>

Final effect

All the handling of the event is basically the above three kinds of processing mechanism, I hope the reader must carefully grasp

The next section predicts:

Dialog dialog box component