向Button上添加OnclickListener的另一种方式
package wjq.WidgetDemo;

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 {
private Chronometer mChronometer;
/* (non-Javadoc)
* @see android.app.Activity#onCreate(android.os.Bundle)
*/
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.chronometerpage);
Button button;

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

// Watch for button clicks.
button = (Button) findViewById(R.id.start);
button.setOnClickListener(mStartListener);

button = (Button) findViewById(R.id.stop);
button.setOnClickListener(mStopListener);

button = (Button) findViewById(R.id.reset);
button.setOnClickListener(mResetListener);

button = (Button) findViewById(R.id.set_format);
button.setOnClickListener(mSetFormatListener);

button = (Button) findViewById(R.id.clear_format);
button.setOnClickListener(mClearFormatListener);
}

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);
}
};
}