Chronometer控件的使用

Chronometer 是android自身提供的计时器控件
用于实现简单的计时功能,避免编写复杂的多线程代码.
使用时在布局文件中声明计时器的位置和属性.
核心方法
start() 计时开始
stop() 计时停止
setBase(SystemClock.elapsedRealtime()) 重置
setFormart() 显示时间
核心接口OnChronometerTickListener,用于监听时间的实时变化.

---

范例代码如下:

1.自定义控件继承Chronometer

public class MyChronometer extends Chronometer {    SimpleDateFormat sdf;    private long currentTime;    private long startMilliSecond=0;    private Vibrator vibrator;    public MyChronometer(Context context, AttributeSet attrs, int defStyle) {        super(context, attrs, defStyle);        init();    }    public MyChronometer(Context context, AttributeSet attrs) {        super(context, attrs);        init();    }    public MyChronometer(Context context) {        super(context);    }    @SuppressLint("SimpleDateFormat")     private void init() {        sdf = new SimpleDateFormat("HH:mm:ss");        this.setText("00:00:00");        currentTime = System.currentTimeMillis();        this.setOnChronometerTickListener(new MyOnChronometerTickListener());    }    /**     * 开始计时     */    @Override    public void start() {        super.start();    }    /**     * 停止计时     */    @Override    public void stop() {        super.stop();    }       /**     * 重置     */    public void reset() {        setBase(SystemClock.elapsedRealtime());        setText("00:00:00");    }    // // 计时监听事件，随时随地的监听时间的变化    class MyOnChronometerTickListener implements OnChronometerTickListener{        @Override        public void onChronometerTick(Chronometer chronometer) {        }    }}

2.在布局文件中声明该自定义控件

<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"    android:orientation="vertical"    tools:context="com.duan.mychronometer.MainActivity" >    <com.duan.mychronometer.MyChronometer        android:id="@+id/myChronometer"        android:layout_width="fill_parent"        android:layout_height="wrap_content"        android:layout_marginLeft="1dip"        android:background="@drawable/shape_gray_rectangle"        android:gravity="center"        android:paddingLeft="4dip"        android:paddingRight="4dip"        android:textColor="@android:color/white"        android:textSize="60sp" />    <LinearLayout        android:layout_width="fill_parent"        android:layout_height="fill_parent"        android:orientation="horizontal" >        <Button            android:id="@+id/start"            android:layout_weight="1"            android:layout_width="0dip"            android:layout_height="wrap_content"            android:text="开始" />        <Button            android:id="@+id/stop"            android:layout_weight="1"            android:layout_width="0dip"            android:layout_height="wrap_content"            android:text="停止" />        <Button            android:id="@+id/reset"            android:layout_weight="1"            android:layout_width="0dip"            android:layout_height="wrap_content"            android:text="重置" />    </LinearLayout></LinearLayout>

3.在需要Chronometer的Activity中调用相关方法

package com.duan.mychronometer;import android.app.Activity;import android.os.Bundle;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;public class MainActivity extends Activity implements OnClickListener {    private MyChronometer mChronometer;    private Button start, stop, reset;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        initView();    }    private void initView() {        mChronometer = (MyChronometer) findViewById(R.id.myChronometer);        start = (Button) findViewById(R.id.start);        stop = (Button) findViewById(R.id.stop);        reset = (Button) findViewById(R.id.reset);        start.setOnClickListener(this);        stop.setOnClickListener(this);        reset.setOnClickListener(this);    }    @Override    public void onClick(View v) {        switch (v.getId()) {        case R.id.start:            mChronometer.start();            break;        case R.id.stop:            mChronometer.stop();            break;        case R.id.reset:            mChronometer.reset();            break;        }    }}