如何在Android开发中使用DatePicker与TimePicke监听时间

<&#63;xml version="1.0" encoding="utf-8"&#63;>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:orientation="vertical"
  android:layout_width="fill_parent"
  android:layout_height="fill_parent"
  >
<TextView
  android:layout_width="fill_parent"
  android:layout_height="wrap_content"
  android:text="选择时间"
  />
  <DatePicker android:id="@+id/datepicker"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:layout_gravity="center_horizontal"
  />
  <TimePicker
  android:id="@+id/timepicker"
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
    android:layout_gravity="center_horizontal"
  />
  <EditText
    android:id="@+id/et"
    android:layout_width="fill_parent"
  android:layout_height="wrap_content"
  android:editable="false"
  android:cursorVisible="false"
  />
</LinearLayout>

package com.ly;
import java.util.Calendar;
import android.app.Activity;
import android.os.Bundle;
import android.widget.DatePicker;
import android.widget.DatePicker.OnDateChangedListener;
import android.widget.EditText;
import android.widget.TimePicker;
import android.widget.TimePicker.OnTimeChangedListener;
/**
 * @author kurting
 * 两个时间控件监听
 *
 */
public class TimeExampleActivity extends Activity {
  private int year;
  private int month;
  private int day;
  private int hour;
  private int minute;
  /** Called when the activity is first created. */
  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    DatePicker datapicker = (DatePicker) findViewById(R.id.datepicker);
    TimePicker timepicker =(TimePicker) findViewById(R.id.timepicker);
    Calendar c =Calendar.getInstance();
    year =c.get(Calendar.YEAR);
    month=c.get(Calendar.MONTH);
    day=c.get(Calendar.DAY_OF_MONTH);
    hour = c.get(Calendar.HOUR);
    minute =c.get(Calendar.MINUTE);
    datapicker.init(year, month, day, new OnDateChangedListener() {
      @Override
      public void onDateChanged(DatePicker view, int year, int monthOfYear,
          int dayOfMonth) {
    TimeExampleActivity.this.year=year;
    TimeExampleActivity.this.month=monthOfYear;
    TimeExampleActivity.this.day=dayOfMonth;
    showDate(year,month,day,hour,minute);
      }
    });
    timepicker.setOnTimeChangedListener(new OnTimeChangedListener() {
      @Override
      public void onTimeChanged(TimePicker view, int hourOfDay, int minute) {
        // TODO Auto-generated method stub
        TimeExampleActivity.this.hour=hourOfDay;
        TimeExampleActivity.this.minute=minute;
      }
    });
  }
  private void showDate(int year, int month, int day, int hour,int minute) {
    EditText et = (EditText) findViewById(R.id.et);
    et.setText(year+"年"+month+"月"+day+"日"+hour+"时"+minute+"分");
  }
}