Android计时器chronometer使用实例讲解

package com.example.android.apis.view;

// Need the following import to get access to the app resources, since this
// class is in a sub-package.
import com.example.android.apis.R;

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;

public class ChronometerDemo extends Activity {
  Chronometer mChronometer;

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    setContentView(R.layout.chronometer);

    Button button;

    mChronometer = (Chronometer) findViewById(R.id.chronometer);

    // Watch for button clicks.
    button = (Button) findViewById(R.id.start);
    button.setOnClickListener(mStartListener);//对应的是开始计时

    button = (Button) findViewById(R.id.stop);
    button.setOnClickListener(mStopListener); //对应的是停止计时

    button = (Button) findViewById(R.id.reset);
    button.setOnClickListener(mResetListener);//对应的是重新置数

    button = (Button) findViewById(R.id.set_format);
    button.setOnClickListener(mSetFormatListener);//对应的是设置时间的显示格式

    button = (Button) findViewById(R.id.clear_format);
    button.setOnClickListener(mClearFormatListener);//对应的是使用非格式的计时显示功能
  }

  View.OnClickListener mStartListener = new OnClickListener() {
    public void onClick(View v) {
      mChronometer.start();
    }
  };

  View.OnClickListener mStopListener = new OnClickListener() {
    public void onClick(View v) {
      mChronometer.stop(); 
    }
  };

  View.OnClickListener mResetListener = new OnClickListener() {
    public void onClick(View v) {
      mChronometer.setBase(SystemClock.elapsedRealtime());
    }
  };

  View.OnClickListener mSetFormatListener = new OnClickListener() {
    public void onClick(View v) {
      mChronometer.setFormat("Formatted time (%s)");
    }
  };

  View.OnClickListener mClearFormatListener = new OnClickListener() {
    public void onClick(View v) {
      mChronometer.setFormat(null);
    }
  };
}