三种定时器的使用
16lz
2021-01-26
三种定时器的使用
Android中使用定时器的三种方法学习与整理
按惯例是图示:
因为都比较简单,所以就直接贴代码(虑去再次点击停止的操作),有个全局的Handler负责接收消息更新UI
第一种,Thread.sleep();方法
Runnable runnable = new Runnable() { @Override public void run() { while (true) { mHandler.sendEmptyMessage(0); try { Thread.sleep(1000); } catch (InterruptedException e) { e.printStackTrace(); } } } };new Thread(runnable).start();}第二种方法:Handler的postDelay()方法
final Runnable runnable = new Runnable() { @Override public void run() { if (isStart2) { mHandler.sendEmptyMessage(0); mHandler.postDelayed(this, 1000); } } };mHandler.postDelayed(runnable, 1000); }第三种:Timer和TimerTask
private Timer timer = new Timer(); private TimerTask timerTask = new TimerTask() { @Override public void run() { mHandler.sendEmptyMessage(0); } }; timer.schedule(timerTask, 1000, 1000);总的来说第三种方法最方便,不易出错,第二种容易忘记添加出发事件.
贴一下完整代码:
布局文件
<?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" android:paddingBottom="@dimen/activity_vertical_margin" android:paddingLeft="@dimen/activity_horizontal_margin" android:paddingRight="@dimen/activity_horizontal_margin" android:paddingTop="@dimen/activity_vertical_margin" tools:context="com.brioal.timertest.MainActivity"> <TextView android:id="@+id/main_tv" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_centerHorizontal="true" android:layout_marginTop="100dp" android:text="Hello World!" /> <LinearLayout android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_below="@id/main_tv" android:layout_marginTop="100dp" android:gravity="center" android:orientation="vertical"> <Button android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="center" android:layout_margin="5dp" android:onClick="Method1" android:text="方法1:Thread" android:textAllCaps="false" /> <Button android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="center" android:layout_margin="5dp" android:onClick="Method2" android:text="方法2:Handler" android:textAllCaps="false" /> <Button android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_gravity="center" android:layout_margin="5dp" android:onClick="Method3" android:text="方法3:Task" android:textAllCaps="false" /> </LinearLayout></RelativeLayout>MainActivity
package com.brioal.timertest;import android.os.Bundle;import android.os.Handler;import android.os.Message;import android.support.v7.app.AppCompatActivity;import android.view.View;import android.widget.TextView;import java.text.SimpleDateFormat;import java.util.Timer;import java.util.TimerTask;public class MainActivity extends AppCompatActivity { private TextView mTv; private Handler mHandler = new Handler() { @Override public void handleMessage(Message msg) { super.handleMessage(msg); //收到消息后显示当前时间 long current = System.currentTimeMillis(); SimpleDateFormat dateFormat = new SimpleDateFormat("HH:mm:ss"); String time = dateFormat.format(current); mTv.setText(time); } }; private Timer timer = new Timer(); private TimerTask timerTask = new TimerTask() { @Override public void run() { mHandler.sendEmptyMessage(0); } }; private Thread thread1; private boolean isStart1 = false; private boolean isStart2 = false; private boolean isStart3 = false; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); mTv = (TextView) findViewById(R.id.main_tv); } //Thread方法 public void Method1(View view) { Runnable runnable = new Runnable() { @Override public void run() { while (isStart1) { mHandler.sendEmptyMessage(0); try { Thread.sleep(1000); } catch (InterruptedException e) { e.printStackTrace(); } } } }; if (isStart1) { isStart1 = false; } else { isStart1 = true; thread1 = new Thread(runnable); thread1.start(); } } public void Method2(View view) { final Runnable runnable = new Runnable() { @Override public void run() { if (isStart2) { mHandler.sendEmptyMessage(0); mHandler.postDelayed(this, 1000); } } }; if (isStart2) { isStart2 = false; } else { mHandler.postDelayed(runnable, 1000); isStart2 = true; } } public void Method3(View view) { if (isStart3) { timer.cancel(); isStart3 = false; } else { timer.schedule(timerTask, 1000, 1000); isStart3 = true; } }}总结完了,完整Github地址:TimerTest
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