Android Application Development details (vi)--------------event handling mechanism (continued)

1. Engineering Catalogue

2, Testeventactivity.java

Package Com.example.test_event;import Android.os.bundle;import Android.app.activity;import android.view.KeyEvent; Import Android.view.menu;import Android.view.view;import Android.view.view.onclicklistener;import Android.view.view.onfocuschangelistener;import Android.view.view.onkeylistener;import Android.widget.Button; Import Android.widget.checkbox;import Android.widget.compoundbutton;import Android.widget.compoundbutton.oncheckedchangelistener;import Android.widget.edittext;//import Android.widget.textview;import Android.widget.toast;public class Testeventactivity extends Activity {//private TextView MyTextview1, MyTextview2, Mytextview3;private Button myButton1, mybutton2;private EditText myEditText1, Myedittext2;private CheckBox myCheckbox1; @Overrideprotected void OnCreate (Bundle savedinstancestate) {super.oncreate (savedinstancestate); Setcontentview (r.layout.test_event);//MyTextview1 = (TextView) Findviewbyid ( R.ID.TEXTVIEWLAYOUT01);//MyTextview2 = (TextView) Findviewbyid (r.id.textVIEWLAYOUT02);//myTextView3 = (TextView) Findviewbyid (r.id.textviewlayout03); myButton1 = (Button) Findviewbyid ( r.id.buttonlayout01) MyButton2 = (Button) Findviewbyid (r.id.buttonlayout02); myEditText1 = (EditText) Findviewbyid ( R.ID.EDITTEXTLAYOUT01); myEditText2 = (EditText) Findviewbyid (r.id.editviewlayout02); myCheckbox1 = (CheckBox) Findviewbyid (r.id.checkboxlayout01);//Edit the text box's key event Myedittext1.setonkeylistener (new Onkeylistener () {@ Overridepublic boolean OnKey (View arg0, int arg1, keyevent arg2) {//TODO auto-generated method Stubmyedittext1.settext ("" ); return false;}); Myedittext2.setonkeylistener (New Onkeylistener () {@Overridepublic Boolean onKey (View arg0, int arg1, keyevent arg2) {//T ODO auto-generated Method Stubmyedittext2.settext (""); return false;}); /Edit the Focus event of the text box Myedittext1.setonfocuschangelistener (new Onfocuschangelistener () {@Overridepublic void Onfocuschange ( View arg0, Boolean arg1) {//TODO auto-generated method Stubtoast.maketext (Getapplicationcontext (), Myedittext1.gettexT (), Toast.length_long). Show ();}}); Myedittext2.setonfocuschangelistener (New Onfocuschangelistener () {@Overridepublic void Onfocuschange (View arg0, Boolean arg1) {//TODO auto-generated method Stubtoast.maketext (Getapplicationcontext (), Myedittext2.gettext (), Toast.length_long). Show ();}}); /Multi Box Selection event Mycheckbox1.setoncheckedchangelistener (new Oncheckedchangelistener () {@Overridepublic void OnCheckedChanged (Compoundbutton arg0, Boolean arg1) {//TODO auto-generated method Stubtoast.maketext ( Getapplicationcontext (), mycheckbox1.ischecked () + "", Toast.length_long). Show ();}}); /Button Selection Event Mybutton1.setonclicklistener (new Onclicklistener () {@Overridepublic void OnClick (View arg0) {//TODO Auto-generated Method Stubtoast.maketext (Getapplicationcontext (), Mybutton1.gettext (), Toast.length_long). Show ();}); Mybutton2.setonclicklistener (New Onclicklistener () {@Overridepublic void OnClick (View arg0) {//TODO auto-generated Method Stubtoast.maketext (Getapplicationcontext (), Mybutton2.gettext (), Toast.lengtH_long). Show ();}}); @Overridepublic boolean Oncreateoptionsmenu (Menu menu) {//Inflate the menu; This adds items to the action bar if it is PR Esent.getmenuinflater (). Inflate (r.menu.test_event, menu); return true;}}

3. layout file

<linearlayout xmlns:android= "http://schemas.android.com/apk/res/android" android:layout_width= "Match_parent" android:layout_height= "match_parent" android:orientation= "vertical" > <tablelayout android:id= "@+id/myT Ablelayout "android:layout_width=" wrap_content "android:layout_height=" wrap_content "> <TableRo w> <textview android:id= "@+id/textviewlayout01" android:layout_width= "Wrap_ Content "android:layout_height=" wrap_content "android:text=" user name "/> <editt Ext android:id= "@+id/edittextlayout01" android:layout_width= "Fill_parent" and            Roid:scrollhorizontally= "true" android:text= "admin"/> </TableRow> <TableRow> <textview android:id= "@+id/textviewlayout02" android:layout_width= "Wrap_conten T "Android:layout_height= "wrap_content" android:text= "User password"/> <edittext android:id= "@+i                d/editviewlayout02 "android:layout_width=" Fill_parent "android:password=" true " Android:scrollhorizontally= "true" android:text= "123"/> </TableRow> &LT;TABLEROW&G            T                <textview android:id= "@+id/textviewlayout03" android:layout_width= "Wrap_content"                android:layout_height= "Wrap_content" android:text= "Automatic login"/> <checkbox Android:id= "@+id/checkboxlayout01" android:layout_width= "Wrap_content" Android:layout_heig ht= "Wrap_content"/> </TableRow> <TableRow> <button android:id= " @+id/buttonlayout01 "android:layout_width=" wrap_content "android:layout_height=" wrap_content         "       android:text= "Login"/> <button android:id= "@+id/buttonlayout02" Androi        D:layout_width= "Wrap_content" android:layout_height= "Wrap_content" android:text= "Cancel"/> </TableRow> </TableLayout></LinearLayout>

Knowledge

Common event listeners in Android:

(1) Click event View.onclicklistener: This event occurs when the user touches a component or the arrow key is pressed, and the process is onclick ()

(2) Focus event View.onfocuschangelistener: This event occurs when the component Gets or loses focus, and the processing method is Onfocuschange ()

(3) Key event View.onkeylistener: Generated when the user presses or releases a key on the device, processing method OnKey ()

(4) Touch event View.ontouchlistener: When the device has touch function, touch the screen to produce the event, processing Method Ontouch ()

(5) Create context menu event View.oncreatecontextmenulistener: The event is generated when the context menu is created, and the processing method is Oncreatecontextmenu ()

Event Processing steps:

(1) Creating an event listener

(2) Registering event listeners for the component to respond to events

(3) Write implementation code in the event handling method

Android Application Development details (vi)--------------event handling mechanism (continued)