Android实现倒计时方法汇总

android开发中经常会有倒计时的功能，下面将总结出常见的集中实现方式。

1.直接使用handler的消息机制来实现

xml布局中文件如下：

<?xml version="1.0" encoding="utf-8"?>
<linearlayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="match_parent"
  android:layout_height="match_parent"
  android:orientation="horizontal" >

  <button
    android:id="@+id/button"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:onclick="clickbutton"
    android:text="开始计时" />


</linearlayout>

java代码如下：

import android.app.activity;
import android.os.bundle;
import android.os.handler;
import android.os.message;
import android.view.view;
import android.widget.button;

public class firstactivity extends activity{

  private button button;
  private int count = 60;
  private int count_time = 0;
  @override
  protected void oncreate(bundle savedinstancestate) {
    super.oncreate(savedinstancestate);
    setcontentview(r.layout.first_activity);
    button = (button) findviewbyid(r.id.button);

  }

  private handler handler = new handler(){

    @override
    public void handlemessage(message msg) {
      if(count <= 0){
        count = 60;
        button.settext("重新计时");
        button.setclickable(true);
        return;
      }
      count--;
      button.settext(""+count);
      sendemptymessagedelayed(count_time,1000);
    }
  };

  public void clickbutton(view view){
    handler.sendemptymessage(count_time);
    button.setclickable(false);
  }
}

2.使用timer和timertask，结合handler一起实现倒计时

import java.util.timer;
import java.util.timertask;

import android.app.activity;
import android.os.bundle;
import android.os.handler;
import android.os.message;
import android.view.view;
import android.widget.button;

public class firstactivity extends activity{

  private button button;
  private int count = 30;
  private int count_time = 0;

  @override
  protected void oncreate(bundle savedinstancestate) {
    super.oncreate(savedinstancestate);
    setcontentview(r.layout.first_activity);
    button = (button) findviewbyid(r.id.button);

  }

  private handler handler = new handler(){

    @override
    public void handlemessage(message msg) {
      button.settext(""+count);
      if(count <= 0){
        count = 30;
        button.setclickable(true);
        button.settext("重新计时");
        timertask.cancel(); //取消该任务
      }
    }
  };

  private timer timer = new timer();
  private timertask timertask;
  public void clickbutton(view view){
    button.setclickable(false);

    timertask = new timertask() {

      @override
      public void run() {
        count--;
        handler.sendemptymessage(count_time);
      }
    };
    timer.schedule(timertask,0,1000); //0秒后，每过一秒钟执行一次该任务
  }

  @override
  protected void ondestroy() {
    super.ondestroy();
    //释放资源
    if(timertask != null){
      timertask.cancel();
      timertask = null;
    }
    if(timer != null){
      timer.cancel();
      timer = null;
    }
  }
}

3.使用android自带的原生倒计时类 countdowntimer

import android.app.activity;
import android.os.bundle;
import android.os.countdowntimer;
import android.view.view;
import android.widget.button;

public class firstactivity extends activity{

  private button button;

  private countdowntimer timer;

  @override
  protected void oncreate(bundle savedinstancestate) {
    super.oncreate(savedinstancestate);
    setcontentview(r.layout.first_activity);
    button = (button) findviewbyid(r.id.button);

  }

  public void clickbutton(view view){
    button.setclickable(false);
    //第一个参数：倒计时的毫秒数；第二个参数：接收ontick回调的时间间隔
    timer = new countdowntimer(30000, 10) {
       public void ontick(long millisuntilfinished) {
         button.settext(millisuntilfinished / 1000 + "秒");
       }
       public void onfinish() {
         button.settext("重新计时");
         button.setclickable(true);
       }
     };
    timer.start();
  }
  @override
  protected void ondestroy() {
    super.ondestroy();
    if(timer != null){
      timer.cancel();
    }
  }
}

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。