android使用datepicker计算年龄

<RelativeLayout  ns:android=\"http://schemas.android.com/apk/res/android\"
  ns:tools=\"http://schemas.android.com/tools\"
 android:layout_width=\"match_parent\"
 android:layout_height=\"match_parent\"
 android:paddingBottom=\"@dimen/activity_vertical_margin\"
 android:paddingLeft=\"@dimen/activity_horizontal_margin\"
 android:paddingRight=\"@dimen/activity_horizontal_margin\"
 android:paddingTop=\"@dimen/activity_vertical_margin\"
 tools:context=\"com.example.datepicker.MainActivity\" >

 <TextView
  android:id=\"@+id/editText\"
  android:layout_width=\"wrap_content\"
  android:layout_height=\"wrap_content\"
  android:layout_centerHorizontal=\"true\"
  android:layout_centerVertical=\"true\"
  android:hint=\"选择你的出生年月\" />

 <Button
  android:id=\"@+id/select\"
  android: =\"SelectAge\"
  android:layout_width=\"wrap_content\"
  android:layout_height=\"wrap_content\"
  android:layout_align line=\"@+id/editText\"
  android:layout_alignBottom=\"@+id/editText\"
  android:layout_alignParentLeft=\"true\"
  android:text=\"选择年龄\" />

</RelativeLayout>

package com.example.datepicker;

import java.text.SimpleDateFormat;
import java.util.Date;

import android.app.Activity;
import android.app.DatePickerDialog;
import android.app.DatePickerDialog.OnDateSetListener;
import android.os.Bundle;
import android.view.View;

import android.view.Window;
import android.widget.DatePicker;

import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends Activity implements OnDateSetListener {
 private TextView mText;

 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  requestWindowFeature(Window.FEATURE_NO_ );
  setContentView(R.layout.activity_main);
  mText = (TextView) findViewById(R.id.editText);
 }

 public void SelectAge(View v) {
// 这设置默认显示的日期 我选的2000年1月1日       月这是从0开始 0 是一月
  new DatePickerDialog(MainActivity.this, this, 2000, 0, 1).show();

 }

 @Override
 public void onDateSet(DatePicker view, int year, int monthOfYear, int dayOfMonth) {
  // TODO Auto-generated method stub
//  选择1月会是0 要把月份+1
  Toast.makeText(MainActivity.this, \"你选择的是\" + year + \"年\" + (monthOfYear+1) + \"月\" + dayOfMonth + \"日\",
    Toast.LENGTH_LONG).show();
  SimpleDateFormat format = new SimpleDateFormat(\"yyyy\");
  int NowYear = Integer.parseInt(format.format(new Date()));
  mText.setText(\"你今年\" + (NowYear - year) + \"岁\");

 }

}