Android中使用定时器的三种方法

本文实例为大家分享了Android中使用定时器的三种方法，供大家参考，具体内容如下

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

第一种方法: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

更多内容请点击专题《java定时功能》进行学习。