Android Application Development For Dummies, 2nd Edition

Getting Choosy with Dates and Times

A Task Reminder application without a way to set the date and time is a poor Task Reminder application — it would only be a simple task list application.

If you’ve programmed dates and times in another programming language, you realize that building a mechanism for a user to enter the date and time can be a painstaking process. The Android platform comes to your rescue by providing two classes to assist you: DatePicker and TimePicker. These pickers also provide built-in classes for opening a dialog box where the user selects a date and time. Therefore, you can either embed the DatePicker or TimePicker into your application’s views or use the DialogFragment classes.

Creating picker buttons

The reminder_edit.xml file contains mechanisms to help show the DatePicker and TimePicker (under the EditText definitions described earlier). These two buttons have labels above them, as shown in Listing 11-1.

Listing 11-1: The Date and Time Buttons with Their Corresponding TextView Labels

<TextView android:layout_width=”wrap_content” →1

android:layout_height=”wrap_content”

android:text=”@string/date” />

<Button →4

android:id=”@+id/reminder_date”

android:layout_height=”wrap_content”

android:layout_width=”wrap_content”

/>

<TextView android:layout_width=”wrap_content” →9

android:layout_height=”wrap_content”

android:text=”@string/time” />

<Button →12

android:id=”@+id/reminder_time”

android:layout_height=”wrap_content”

android:layout_width=”wrap_content” ...