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