android基础-Toast提示框、日历视图（CalendarView）组件、日期、时间选择器DatePicker和TimerPicker等

1. Toast提示框

       // 创建一个Toast提示信息
                Toast toast = Toast.makeText(MainActivity.this
                        , "简单的提示信息"
                        , Toast.LENGTH_SHORT);
                toast.show();

2. 日历视图（CalendarView）组件

实例：选择您的生日

public class MainActivity extends AppCompatActivity {
    CalendarView cv;
    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        cv = (CalendarView)findViewById(R.id.calendarView);
        // 为CalendarView组件的日期改变事件添加事件监听器
        cv.setOnDateChangeListener(new CalendarView.OnDateChangeListener()
        {
            @Override
            public void onSelectedDayChange(CalendarView view, int year,
                                            int month, int dayOfMonth)
            {
                // 使用Toast显示用户选择的日期
                Toast.makeText(MainActivity.this,
                        "你生日是" + year + "年" + month + "月"
                                + dayOfMonth + "日",
                        Toast.LENGTH_SHORT).show();
            }
        });
    }
}

<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="选择您的生日："/>
    <!-- 设置以星期二作为每周第一天
    设置该组件总共显示4个星期
    并对该组件的日期时间进行了定制 -->
    <CalendarView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:firstDayOfWeek="3"
        android:shownWeekCount="4"
        android:selectedWeekBackgroundColor="#aff"
        android:focusedMonthDateColor="#f00"
        android:weekSeparatorLineColor="#ff0"
        android:unfocusedMonthDateColor="#f9f"
        android:id="@+id/calendarView" />
</LinearLayout>

3. 日期、时间选择器DatePicker和TimerPicker

实例：用户选择日期和时间

    // 定义5个记录当前时间的变量
    private int year;
    private int month;
    private int day;
    private int hour;
    private int minute;
    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        DatePicker datePicker = (DatePicker)
                findViewById(R.id.datePicker);
        TimePicker timePicker = (TimePicker)
                findViewById(R.id.timePicker);
        // 获取当前的年、月、日、小时、分钟
        Calendar c = Calendar.getInstance();
        year = c.get(Calendar.YEAR);
        month = c.get(Calendar.MONTH);
        day = c.get(Calendar.DAY_OF_MONTH);
        hour = c.get(Calendar.HOUR);
        minute = c.get(Calendar.MINUTE);
        // 初始化DatePicker组件，初始化时指定监听器
        datePicker.init(year, month, day, new OnDateChangedListener()
        {
            @Override
            public void onDateChanged(DatePicker arg0, int year
                    , int month, int day)
            {
                MainActivity.this.year = year;
                MainActivity.this.month = month;
                MainActivity.this.day = day;
                // 显示当前日期、时间
                showDate(year, month, day, hour, minute);
            }
        });
        timePicker.setEnabled(true);
        // 为TimePicker指定监听器
        timePicker.setOnTimeChangedListener(new OnTimeChangedListener()
        {
            @Override
            public void onTimeChanged(TimePicker view
                    , int hourOfDay, int minute)
            {
                MainActivity.this.hour = hourOfDay;
                MainActivity.this.minute = minute;
                // 显示当前日期、时间
                showDate(year, month, day, hour, minute);
            }
        });
    }
    // 定义在EditText中显示当前日期、时间的方法
    private void showDate(int year, int month
            , int day, int hour, int minute)
    {
        EditText show = (EditText) findViewById(R.id.show);
        show.setText("您的购买日期为：" + year + "年"
                + (month + 1) + "月" + day + "日  "
                + hour + "时" + minute + "分");
    }

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="选择购买本书的具体时间"/>
    <!-- 定义一个DatePicker组件 -->
    <DatePicker android:id="@+id/datePicker"
        android:layout_width="wrap_content"
        android:layout_height="200dp"
        android:layout_gravity="center_horizontal"
        android:startYear="2000"
        android:endYear="2016"
        android:calendarViewShown="true"
        android:spinnersShown="true"/>
    <!-- 定义一个TimePicker组件 -->
    <TimePicker android:id="@+id/timePicker"
        android:layout_width="wrap_content"
        android:layout_height="100dp"
        android:layout_gravity="center_horizontal"/>
    <!-- 显示用户输入日期、时间的控件 -->
    <EditText android:id="@+id/show"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:editable="false"
        android:cursorVisible="false"/>
</LinearLayout>