Android DatePickerDialog TimePickerDialog

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:onClick="datePickerDialog"
        android:text="DatePickerDialog" />
    
    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:onClick="timePickerDialog"
        android:text="TimePickerDialog" />

</LinearLayout>

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    /**
     * DatePickerDialog和TimePickerDialog都继承于AlertDialog，基本方法和DataPicker和TimePicker组件一样，
     * 只需要调用Dialog的show()方法来显示，在构造方法里传入回调监听
     * @param v
     */
    int year = Calendar.getInstance().get(Calendar.YEAR);
    int month = Calendar.getInstance().get(Calendar.MONTH);
    int dayOfMonth = Calendar.getInstance().get(Calendar.DAY_OF_MONTH);
    public void datePickerDialog(View v){
        DatePickerDialog dialog = new DatePickerDialog(MainActivity.this, new OnDateSetListener() {
            @Override
            public void onDateSet(DatePicker view, int year, int month, int dayOfMonth) {
                Toast.makeText(MainActivity.this, year+"-"+(month+1)+"-"+dayOfMonth, Toast.LENGTH_SHORT).show();
                
            }
        }, year, month, dayOfMonth);
        dialog.show();
    }
    
    int hourOfDay = Calendar.getInstance().get(Calendar.HOUR_OF_DAY);
    int minute = Calendar.getInstance().get(Calendar.HOUR_OF_DAY);
    public void timePickerDialog(View v){
        TimePickerDialog dialog = new TimePickerDialog(MainActivity.this, new OnTimeSetListener() {
            
            @Override
            public void onTimeSet(TimePicker view, int hourOfDay, int minute) {
                Toast.makeText(MainActivity.this, hourOfDay+"："+minute, Toast.LENGTH_SHORT).show();
            }
        }, hourOfDay, minute, true);
        dialog.show();
    }
}