本文实例为大家分享了Android实现简单计时器的具体代码，供大家参考，具体内容如下

布局

在res/layout 下进行布局

xmlns:android="http://schemas.android.com/apk/res/android"

xmlns:tools="http://schemas.android.com/tools"

xmlns:app="http://schemas.android.com/apk/res-auto"

android:layout_width="match_parent"

android:layout_height="match_parent"

tools:context=".MainActivity">

android:orientation="vertical"

android:layout_width="match_parent"

android:layout_height="match_parent" tools:layout_editor_absoluteY="0dp"

tools:layout_editor_absoluteX="0dp">

android:text="00:00:00"

android:textSize="60sp"

android:gravity="center"

android:layout_width="match_parent"

android:layout_height="wrap_content" android:id="@+id/timeView"/>

android:text="start"

android:onClick="onClickStart"

android:layout_width="match_parent"

android:layout_height="wrap_content" android:id="@+id/start"/>

android:text="stop"

android:onClick="onClickStop"

android:layout_width="match_parent"

android:layout_height="wrap_content" android:id="@+id/stop"/>

android:text="reset"

android:onClick="onClickReset"

android:layout_width="match_parent"

android:layout_height="wrap_content" android:id="@+id/reset"/>

MainActivity

package com.test;

import android.os.Handler;

import android.support.v7.app.AppCompatActivity;

import android.os.Bundle;

import android.view.View;

import android.widget.TextView;

public class MainActivity extends AppCompatActivity {

private int seconds = 0;

private boolean running = false; //计时状态

private boolean wasRunning = false; //保存running的状态

//app进入后台，暂停计时

@Override

protected void onStop() {

super.onStop();

wasRunning = running;

running = false;

}

//重新进入app，开始计时

@Override

protected void onStart() {

super.onStart();

if(wasRunning) running = true;

}

//失去焦点(如分屏)，暂停计时

@Override

protected void onPause() {

super.onPause();

wasRunning = running;

running = false;

}

//获得焦点,重新开始计时

@Override

protected void onResume() {

super.onResume();

if(wasRunning) running = true;

}

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

//获取保存的状态

if(savedInstanceState!=null){

seconds = savedInstanceState.getInt("seconds");

running = savedInstanceState.getBoolean("running");

wasRunning = savedInstanceState.getBoolean("wasRunning");

}

runTime();

}

/**

*保存状态

*/

@Override

public void onSaveInstanceState(Bundle saveInstanceState) {

super.onSaveInstanceState(saveInstanceState);

saveInstanceState.putInt("seconds",seconds);

saveInstanceState.putBoolean("running",running);

saveInstanceState.putBoolean("wasRunning",wasRunning);

}

/**

* 响应button的onClick事件

* 方法名和onClick的值一致

*/

public void onClickStart(View button){

running = true;

}

public void onClickStop(View button){

running = false;

}

public void onClickReset(View button){

running = false;

seconds = 0;

}

/**

* 注意 ui线程不能被堵塞，因此不能在ui线程中调用sleep方法

* 只允许ui线程更新界面，不能在后台线程更新界面

*

* ** 使用ui线程的Handler定时更新 **

* 将任务封装到 Runnable的run方法中 ，通过Handler的

* post(立即提交任务)或postDelayed(实现定时调度)方法提交到ui线程

*/

private void runTime(){

final Handler handler = new Handler();

handler.post(new Runnable() {

@Override

public void run() {

final TextView textView = findViewById(R.id.timeView);

int hour = seconds /3600%24;

int minute = seconds%3600/60;

String time = String.format("%02d:%02d:%02d",hour,minute,seconds%60);

textView.setText(time);

if(running) seconds++;

handler.postDelayed(this,1000);

}

}

);

}

}

测试

完成

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脚本之家。