Android Tutorials DatePicker and TimePicker

DatePicker と TimePicker は似たようなサンプルだから一つに纏めようとしたらすんなり動いた。
それなりに理解してきたかな？

画面はXML、他は全部Javaで書く。画面もJavaで書けるけど非推奨の様です。画面いじる様にレイアウトエディターがあるけどこれはどうなんだろう・・・ なんだか良くわからないですね。

エミュレータが起動も動作も超もっさりなのは我慢ですかね・・・

main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:orientation="vertical">
    <TextView android:id="@+id/dateDisplay"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text=""/>
    <Button android:id="@+id/pickDate"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Change the date"/>
    <Button android:id="@+id/pickTime"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Change the time"/>
</LinearLayout>

HelloDatePicker.java

package com.example.hellodatepicker;
import java.util.Calendar;
import android.app.Activity;
import android.app.DatePickerDialog;
import android.app.Dialog;
import android.app.TimePickerDialog;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.DatePicker;
import android.widget.TextView;
import android.widget.TimePicker;
public class HelloDatePicker extends Activity {
    /** Called when the activity is first created. */
    private TextView mDateDisplay;
    private Button mPickDate;
    private Button mPickTime;
    private int mYear;
    private int mMonth;
    private int mDay;
    private int mHour;
    private int mMinute;
    static final int DATE_DIALOG_ID = 0;
    static final int TIME_DIALOG_ID = 1;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        // capture our view elements
        mDateDisplay = (TextView) findViewById(R.id.dateDisplay);
        mPickDate = (Button) findViewById(R.id.pickDate);
        mPickTime = (Button) findViewById(R.id.pickTime);
        // add a click listener to the button
        mPickDate.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) { showDialog(DATE_DIALOG_ID); }
        });
        mPickTime.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) { showDialog(TIME_DIALOG_ID); }
        });
        // get the current date
        final Calendar c = Calendar.getInstance();
        mYear = c.get(Calendar.YEAR);
        mMonth = c.get(Calendar.MONTH);
        mDay = c.get(Calendar.DAY_OF_MONTH);
        mHour = c.get(Calendar.HOUR_OF_DAY);
        mMinute = c.get(Calendar.MINUTE);
        // display the current date
        updateDisplay();
    }
    @Override
    protected Dialog onCreateDialog(int id) {
        switch (id) {
        case DATE_DIALOG_ID:
            return new DatePickerDialog(this, mDateSetListener, mYear, mMonth, mDay);
        case TIME_DIALOG_ID:
            return new TimePickerDialog(this, mTimeSetListener, mHour, mMinute, false);
        }
        return null;
    }
    private void updateDisplay() {
        mDateDisplay.setText(
            new StringBuilder()
                // Month is 0 based so add 1
                .append(mMonth + 1).append("-")
                .append(mDay).append("-")
                .append(mYear).append(" ")
                .append(pad(mHour)).append(":")
                .append(pad(mMinute)));
    }
    // the callback received when the user "sets" the date in the dialog
    private DatePickerDialog.OnDateSetListener mDateSetListener =
        new DatePickerDialog.OnDateSetListener() {
            public void onDateSet(DatePicker view, int year, int monthOfYear, int dayOfMonth) {
                mYear = year;
                mMonth = monthOfYear;
                mDay = dayOfMonth;
                updateDisplay();
            }
    };
    private TimePickerDialog.OnTimeSetListener mTimeSetListener =
        new TimePickerDialog.OnTimeSetListener() {
            public void onTimeSet(TimePicker view, int hourOfDay, int minute) {
                mHour = hourOfDay;
                mMinute = minute;
                updateDisplay();
            }
    };
    private static String pad(int c) {
        if (c >= 10)
            return String.valueOf(c);
        else
            return "0" + String.valueOf(c);
    }
}