android使用datepicker计算年龄

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_TITLE);
  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");

 }

}