DatePickerDialog in Android

Android DatePicker is a user interface control that is used to select the date by day, month, and year in the android application. DatePicker is used to ensure that the users will select a valid date. In android DatePicker having two modes, the first one shows the complete calendar and the second one shows the dates in the spinner view. One can create a DatePicker control in two ways either manually in the XML file or create it in the Activity file programmatically. We are going to do it programmatically by using Java.

Note: To implement DatePicker using Kotlin please refer to this.

Approach

Step 1: Create a New Project

To create a new project in Android Studio please refer to How to Create/Start a New Project in Android Studio. Note that select Java as the programming language.

Step 2: Working with activity_main.xml file

In the activity_main.xml file add only a TextView to display the selected date and a Button to select the date from the DatePickerDialog. Below is the complete code for the activity_main.xml file.

Step 3: Create a new class and names as DatePicker

Now create a new class by going to the package and right-click on it and select new and then Java Class. Name the class as DatePicker and its superclass as DialogFragment (androidx.fragment.app.DialogFragment) and click OK.

Now override a method onCreateDialog and instead of returning super.onCreateDialog return an instance of DatePickerDialog. 

@NonNull

   @Override

   public Dialog onCreateDialog(@Nullable Bundle savedInstanceState) {

       return new DatePickerDialog();

   }

Now pass parameters to the constructor of DatePickerDialog which requires context, OnDateSetListener, year, month, dayOfMonth.

• Pass the getActivity method for the context.
• For OnDateSetListener typecast the getActivity method to OnDateSetListener.
• For the year, month, and dayOfMonth create an instance of calendar class and assign the year, month, and dayOfMonth to variables of type int.
• Pass year and month and dayOfMonth so that when the DatePickerDialog opens it has the current date.

@NonNull

@Override

public Dialog

onCreateDialog(@Nullable Bundle savedInstanceState)

{

   Calendar mCalendar = Calendar.getInstance();

   int year = mCalendar.get(Calendar.YEAR);

   int month = mCalendar.get(Calendar.MONTH);

   int dayOfMonth = mCalendar.get(Calendar.DAY_OF_MONTH);

   return new DatePickerDialog(

       getActivity(),

       (DatePickerDialog.OnDateSetListener)getActivity(),

       year, month, dayOfMonth);

}

The complete code for the DatePicker.java class is given below. 

Step 4: Working with MainActivity.java file

Now In the MainActivity.java file, create an object of both TextView and Button and map the components(TextView and Button) with their ids. 

TextView tvDate;

Button btPickDate;

tvDate = findViewById(R.id.tvDate);

btPickDate = findViewById(R.id.btPickDate);

Implement OnDateSetListener of DatePickerDialog class and override onDateSet() method.  The  onDateSet() method will set the date after selection in the tvDate TextView. 

 @Override

   public void onDateSet(DatePicker view, int year, int month, int dayOfMonth)

 {

       // Create a Calendar instance

       Calendar mCalendar = Calendar.getInstance();

       // Set static variables of Calendar instance

       mCalendar.set(Calendar.YEAR,year);

       mCalendar.set(Calendar.MONTH,month);

       mCalendar.set(Calendar.DAY_OF_MONTH,dayOfMonth);

       // Get the date in form of string

       String selectedDate = DateFormat.getDateInstance(DateFormat.FULL).format(mCalendar.getTime());

       // Set the textview to the selectedDate String

       tvDate.setText(selectedDate);

}

In the onClick() method implement setOnClickListener of btPickDate. Create an instance of DatePicker(our class). Use the show method of the instance and pass getSupportFragmentManager() and a Tag. The complete code for the MainActivity.java file is given below.

Output: Run on Emulator