MainActivity

package com.example.android.todolista;

import android.app.DatePickerDialog;
import android.app.Dialog;
import android.app.DialogFragment;
import android.app.TimePickerDialog;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.text.format.DateFormat;
import android.view.View;
import android.widget.Button;
import android.widget.DatePicker;
import android.widget.EditText;
import android.widget.RadioButton;
import android.widget.TextView;
import android.widget.TimePicker;
import android.widget.Toast;

import java.util.Calendar;

public class MainActivity extends AppCompatActivity {
    private EditText etItemDesc;
    private static TextView tvDate;
    private static TextView tvTime;
    private Button btnChooseDate;
    private Button btnChooseTime;
    private Button btnAdd;
    private Button btnCancel;
    private RadioButton rbtnDone;

    public static class TimePickerFragment extends DialogFragment
            implements TimePickerDialog.OnTimeSetListener {

        @Override
        public Dialog onCreateDialog(Bundle savedInstanceState) {
            // Use the current time as the default values for the picker
            final Calendar c = Calendar.getInstance();
            int hour = c.get(Calendar.HOUR_OF_DAY);
            int minute = c.get(Calendar.MINUTE);

            // Create a new instance of TimePickerDialog and return it
            return new TimePickerDialog(getActivity(), this, hour, minute,
                    DateFormat.is24HourFormat(getActivity()));
        }

        public void onTimeSet(TimePicker view, int hourOfDay, int minute) {
            tvTime.setText(hourOfDay+":"+minute);
        }
    }

    public static class DatePickerFragment extends DialogFragment
            implements DatePickerDialog.OnDateSetListener {

        @Override
        public Dialog onCreateDialog(Bundle savedInstanceState) {
            // Use the current date as the default date in the picker
            final Calendar c = Calendar.getInstance();
            int year = c.get(Calendar.YEAR);
            int month = c.get(Calendar.MONTH);
            int day = c.get(Calendar.DAY_OF_MONTH);

            // Create a new instance of DatePickerDialog and return it
            return new DatePickerDialog(getActivity(), this, year, month, day);
        }

        public void onDateSet(DatePicker view, int year, int month, int day) {
            tvDate.setText(day+"."+month+"."+year);
        }
    }

    public void addButtonClick(View v) {
        Toast.makeText(this, etItemDesc.getText() + ", " + tvDate.getText()
                + ", " + tvTime.getText() + ", " + rbtnDone.isChecked(), Toast.LENGTH_SHORT).show();
    }

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

        etItemDesc = (EditText) findViewById(R.id.etItemDesc);
        rbtnDone = (RadioButton) findViewById(R.id.radioButton);
        tvDate = (TextView) findViewById(R.id.tvDate);
        tvTime = (TextView) findViewById(R.id.tvTime);
        btnChooseDate = (Button) findViewById(R.id.btnChooseDate);
        btnChooseTime = (Button) findViewById(R.id.btnChooseTime);
        btnAdd = (Button) findViewById(R.id.btnAdd);
        btnCancel = (Button) findViewById(R.id.btnCancel);

        btnChooseDate.setOnClickListener(new View.OnClickListener(){
            @Override
            public void onClick(View v) {
                DialogFragment newFragment = new DatePickerFragment();
                newFragment.show(getFragmentManager(), "datePicker");
            }
        });

        btnChooseTime.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                DialogFragment newFragment = new TimePickerFragment();
                newFragment.show(getFragmentManager(), "timePicker");
            }
        });
    }
}