Question

I have created an xml layout which is in effect a grid. I need to use it as a calendar and have read about the calendar class but i’ve been unable to get any of the code it suggests to work.

How would i go about displaying the current year,month and days in the various text views?

This is what i have so far:

Calendar c = Calendar.getInstance(); 
    int month = c.get(Calendar.MONTH);

    String month_name = Integer.toString(month);

    TextView monthdisp = (TextView) findViewById(R.id.month_disp);

    monthdisp.setText(month_name);

    setContentView(R.layout.main);

However a null pointer excpetion is generated at monthdisp.setText(month_name);

Answer 1

See the Android Developers guide To get the current year, month and days you’d use the following:

Calendar cal = Calendar.getInstance();
int year = cal.get(Calendar.YEAR); // get the current year
int month = cal.get(Calendar.MONTH); // month...
int day = cal.get(Calendar.DAY_OF_MONTH); // current day in the month

// sets your textview to e.g. 2012/03/15 for today
textview.setText("Year / month / day: "+ year + "/" + month + "/" + day);

Alternatively, you can use SimpleDateFormat like so:

// set-up the desired formatting
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
Calendar cal = Calendar.getInstance();

Date now = cal.getTime(); // set the current datetime in a Date-object

// SimpleDateFormat.format( Date date ) returns a formatted string
// with the predefined format
String mTimeString = sdf.format( now ); // contains yyyy-MM-dd (e.g. 2012-03-15 for March 15, 2012)

TextView textView = new TextView(this);
textView.setText( mTimeString );

The other way around also works:

SimpleDateFormat sdf = new SimpleDateFormat("dd-MM-yyyy");

String mDateString = "14-05-2012";
Date mDate = sdf.parse( mDateString ); // returns a Date-object
                                       // with date set to May 14, 2012