Android實現簡單計時器功能
阿新 • • 發佈:2020-10-22
本文例項為大家分享了Android實現簡單計時器的具體程式碼,供大家參考,具體內容如下
佈局
在res/layout 下進行佈局
<?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout 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"> <LinearLayout android:orientation="vertical" android:layout_width="match_parent" android:layout_height="match_parent" tools:layout_editor_absoluteY="0dp" tools:layout_editor_absoluteX="0dp"> <TextView 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"/> <Button android:text="start" android:onClick="onClickStart" android:layout_width="match_parent" android:layout_height="wrap_content" android:id="@+id/start"/> <Button android:text="stop" android:onClick="onClickStop" android:layout_width="match_parent" android:layout_height="wrap_content" android:id="@+id/stop"/> <Button android:text="reset" android:onClick="onClickReset" android:layout_width="match_parent" android:layout_height="wrap_content" android:id="@+id/reset"/> </LinearLayout> </android.support.constraint.ConstraintLayout>
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; //計時狀態 private boolean wasRunning = false; //儲存running的狀態 //app進入後臺,暫停計時 @Override protected void onStop() { super.onStop(); wasRunning = running; running = false; } //重新進入app,開始計時 @Override protected void onStart() { super.onStart(); if(wasRunning) running = true; } //失去焦點(如分屏),暫停計時 @Override protected void onPause() { super.onPause(); wasRunning = running; running = false; } //獲得焦點,重新開始計時 @Override protected void onResume() { super.onResume(); if(wasRunning) running = true; } @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); //獲取儲存的狀態 if(savedInstanceState!=null){ seconds = savedInstanceState.getInt("seconds"); running = savedInstanceState.getBoolean("running"); wasRunning = savedInstanceState.getBoolean("wasRunning"); } runTime(); } /** *儲存狀態 */ @Override public void onSaveInstanceState(Bundle saveInstanceState) { super.onSaveInstanceState(saveInstanceState); saveInstanceState.putInt("seconds",seconds); saveInstanceState.putBoolean("running",running); saveInstanceState.putBoolean("wasRunning",wasRunning); } /** * 響應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執行緒不能被堵塞,因此不能在ui執行緒中呼叫sleep方法 * 只允許ui執行緒更新介面,不能在後臺執行緒更新介面 * * ** 使用ui執行緒的Handler定時更新 ** * 將任務封裝到 Runnable的run方法中 ,通過Handler的 * post(立即提交任務)或postDelayed(實現定時排程)方法提交到ui執行緒 */ 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); } } ); } }
測試
完成
以上就是本文的全部內容,希望對大家的學習有所幫助,也希望大家多多支援我們。