Android countdown and android countdown

Android countdown and android countdown

Preface

When you open the welcome interface of iQiYi and other apps, there is a countdown control in the upper right corner. After the countdown, enter the main interface. Now let's implement this function.

Method 1

Using the java class Timer, TimerTask and android Handler

Ui welcome_activity.xml

<?xml version="1.0" encoding="utf-8"?><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">    <TextView        android:id="@+id/count_down"        android:layout_width="60dp"        android:layout_height="60dp"        android:layout_alignParentRight="true"        android:layout_alignParentTop="true"        android:layout_marginRight="16dp"        android:layout_marginTop="16dp"        android:gravity="center"        android:textSize="32sp"        android:textColor="#50000000"        android:background="@drawable/count_down_background"        tools:text="2"        /></RelativeLayout>

Package com. example. counttimer; import java. util. date; import java. util. timer; import java. util. timerTask; import android. app. activity; import android. content. intent; import android. OS. bundle; import android. OS. handler; import android. view. menu; import android. view. menuItem; import android. view. window; import android. widget. textView; public class WelcomeActivity extends Activity {private final static int COUN T = 1; private TextView countDown; @ Override protected void onCreate (Bundle savedInstanceState) {super. onCreate (savedInstanceState); requestWindowFeature (Window. FEATURE_NO_TITLE); setContentView (R. layout. activity_welcome); initView () ;}// the first and third parameters of sehedule are the time of the first startup delay, and the third parameter is the interval of execution. The Unit is ms.
// Therefore, a message is sent to handler every second to update the UI.
// Three seconds later. In the second sehedule of timer, the private void initView () {countDown = (TextView) findViewById (R. id. count_down); final Timer timer = new Timer (); final long end = System. currentTimeMillis () + 1000*3; timer. schedule (new TimerTask () {@ Override public void run () {handler. sendEmptyMessage (COUNT) ;}}, 0, 1000); // The second parameter of schedule indicates that the method timer in run is run as soon as possible at this time. schedule (new TimerTask () {@ Override public void run () {Intent I = new Intent (WelcomeActivity. this, SecondActivity. class); I. addFlags (Intent. FLAG_ACTIVITY_CLEAR_TASK); startActivity (I); finish (); timer. cancel () ;}, new Date (end) ;}private Handler handler = new Handler () {int num = 2; public void handleMessage (android. OS. message msg) {switch (msg. what) {case COUNT: countDown. setText (String. valueOf (num); num --; break; default: break ;}};};}

count_down_background.xml

<?xml version="1.0" encoding="utf-8"?><shape xmlns:android="http://schemas.android.com/apk/res/android"    android:shape="rectangle">    <corners        android:radius="8dp"/>    <solid        android:color="#1e000000"/></shape>

 

Another empty activity will not be posted.

The result is as follows: Countdown to 0 to SecondActivity

 

Method 2

Use the CountDownTimer class encapsulated by android. Actually, Handler is used internally. All others are the same.

Package com. example. counttimer; import android. app. activity; import android. content. intent; import android. OS. bundle; import android. OS. countDownTimer; import android. view. window; import android. widget. textView; public class WelcomeActivity extends Activity {private final static int COUNT = 1; private TextView countDown; @ Override protected void onCreate (Bundle savedInstanceState) {super. onCreate (savedInstanceState); requestWindowFeature (Window. FEATURE_NO_TITLE); setContentView (R. layout. activity_welcome); initView ();} private void initView () {countDown = (TextView) findViewById (R. id. count_down );
// The CountDownTimer constructor uses the first parameter to indicate the total time, and the second parameter to indicate the interval.
// This means that every xxx calls back the onTick method, and then calls back the onFinish method after xxx. CountDownTimer timer = new CountDownTimer (3200,1000) {int num = 2; @ Override public void onTick (long millisUntilFinished) {countDown. setText (String. valueOf (num); num --;} @ Override public void onFinish (){
// Call Intent I = new Intent (WelcomeActivity. this, SecondActivity. class); I. addFlags (Intent. FLAG_ACTIVITY_CLEAR_TASK); startActivity (I); finish () ;}}; timer. start ();}}