Android 計時器使用官方文檔

想做一個倒計時的小功能，發現了這個，所以搬運官網分享出來。

CountDownTimer

public abstract class CountDownTimer 
extends Object 

java.lang.Object
↳	android.os.CountDownTimer

 

---

Schedule a countdown until a time in the future, with regular notifications on intervals along the way. Example of showing a 30 second countdown in a text field:

 new CountDownTimer(30000, 1000) {

     public void onTick(long millisUntilFinished) {
         mTextField.setText("seconds remaining: " + millisUntilFinished / 1000);
     }

     public void onFinish() {
         mTextField.setText("done!");
     }
  }.start();
 

The calls to onTick(long) are synchronized to this object so that one call to onTick(long) won't ever occur before the previous callback is complete. This is only relevant when the implementation of onTick(long) takes an amount of time to execute that is significant compared to the countdown interval.

 

Summary

Public constructors

CountDownTimer(long millisInFuture, long countDownInterval)

Public methods
final void	cancel() Cancel the countdown.
abstract void	onFinish() Callback fired when the time is up.
abstract void	onTick(long millisUntilFinished) Callback fired on regular interval.
final CountDownTimer	start() Start the countdown.

Inherited methods

From class java.lang.Object

Public constructors

 

CountDownTimer

 

Added in API level 1

<span style="color:inherit">public CountDownTimer (long millisInFuture, 
                long countDownInterval)</span>

 

 

Parameters
millisInFuture	long: The number of millis in the future from the call to start() until the countdown is done and onFinish() is called.
countDownInterval	long: The interval along the way to receive onTick(long) callbacks.

Public methods

 

cancel

 

Added in API level 1

<span style="color:inherit">public final void cancel ()</span>

Cancel the countdown.

 

 

onFinish

 

Added in API level 1

<span style="color:inherit">public abstract void onFinish ()</span>

Callback fired when the time is up.

 

 

onTick

 

Added in API level 1

<span style="color:inherit">public abstract void onTick (long millisUntilFinished)</span>

Callback fired on regular interval.

 

Parameters
millisUntilFinished	long: The amount of time until finished.

 

start

 

Added in API level 1

<span style="color:inherit">public final <a data-cke-saved-href="https://developer.android.com/reference/android/os/CountDownTimer.html" href="https://developer.android.com/reference/android/os/CountDownTimer.html">CountDownTimer</a> start ()</span>

Start the countdown.

 

Returns
CountDownTimer