Android学习第五天--chronometer

xml

<LinearLayout 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"
    tools:context=".MainActivity"
    android:orientation="vertical" >

    <Chronometer
        android:id="@+id/chronometer"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
    
    <Button 
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/button_1"
        android:text="@string/start"/>

    <Button 
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/button_2"
        android:text="@string/stop"/>
    <Button 
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/button_3"
        android:text="@string/reset"/>
</LinearLayout>

java中

package com.will.chronometer;

import android.app.Activity;
import android.os.Bundle;
import android.os.SystemClock;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Chronometer;
import android.widget.Chronometer.OnChronometerTickListener;

public class MainActivity extends Activity implements OnClickListener
{
    Chronometer chronometer = null;
    Button but1 = null;
    Button but2 = null;
    Button but3 = null;
    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        chronometer = (Chronometer)findViewById(R.id.chronometer);
        but1 = (Button)findViewById(R.id.button_1);
        but2 = (Button)findViewById(R.id.button_2);
        but3 = (Button)findViewById(R.id.button_3);
        
        but1.setOnClickListener(this);
        but2.setOnClickListener(this);
        but3.setOnClickListener(this);
        
//        chronometer.setFormat("现在时间是： %s");
        chronometer.setOnChronometerTickListener(new OnChronometerTickListener()
        {
            
            @Override
            public void onChronometerTick(Chronometer chronometer)
            {
                if(SystemClock.elapsedRealtime() - chronometer.getBase() > 5000)
                    chronometer.stop();
            }
        });
    }
    @Override
    public void onClick(View v)
    {
        switch(v.getId())
        {
            case R.id.button_1:
                chronometer.setBase(SystemClock.elapsedRealtime());
                chronometer.start();
                break;
            case R.id.button_2:
                chronometer.stop();
                break;
            case R.id.button_3:
                chronometer.setBase(SystemClock.elapsedRealtime());
                break;
                default:
                break;
        }
    }
}