Question

I am absolutely new to the Android platform and have been building an application while learning the development process.

Currently, I am working on an activity in which i need to deploy 2 date pickers. One is a “Start Date” and the other is an “End date”. I have been following the DatePicker tutorial on the android developers page here: http://developer.android.com/resources/tutorials/views/hello-datepicker.html

For one DatePicker, it works just fine.

Now my problem is, when I replicate the whole process for a second date picker, it shows up just fine on the emulator as well as on the handset. But when no matter which button I press to select the dates, only the first TextView is updated and the second TextView keeps showing the current date.

Here is the code:

package com.datepicker;

import java.util.Calendar;

import android.app.Activity;
import android.app.DatePickerDialog;
import android.app.Dialog;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.DatePicker;
import android.widget.TextView;

public class datepicker extends Activity {

private TextView mDateDisplay;
private TextView endDateDisplay;
private Button mPickDate;
private Button endPickDate;
private int mYear;
private int mMonth;
private int mDay;

static final int START_DATE_DIALOG_ID = 0;
static final int END_DATE_DIALOG_ID = 0;


/** Called when the activity is first created. */
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    /*  capture our View elements for the start date function   */
    mDateDisplay = (TextView) findViewById(R.id.startdateDisplay);
    mPickDate = (Button) findViewById(R.id.startpickDate);

    /* add a click listener to the button   */
    mPickDate.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {
            showDialog(START_DATE_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);

    /* display the current date (this method is below)  */
    updateStartDisplay();


 /* capture our View elements for the end date function */
    endDateDisplay = (TextView) findViewById(R.id.enddateDisplay);
    endPickDate = (Button) findViewById(R.id.endpickDate);

    /* add a click listener to the button   */
    endPickDate.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {
            showDialog(END_DATE_DIALOG_ID);
        }
    });

    /* get the current date */
    final Calendar c1 = Calendar.getInstance();
    mYear = c1.get(Calendar.YEAR);
    mMonth = c1.get(Calendar.MONTH);
    mDay = c1.get(Calendar.DAY_OF_MONTH);

    /* display the current date (this method is below)  */
    updateEndDisplay();
}



private void updateEndDisplay() {
    endDateDisplay.setText(
            new StringBuilder()
                // Month is 0 based so add 1
                .append(mMonth + 1).append("-")
                .append(mDay).append("-")
                .append(mYear).append(" "));

}



private void updateStartDisplay() {
    mDateDisplay.setText(
            new StringBuilder()
                // Month is 0 based so add 1
                .append(mMonth + 1).append("-")
                .append(mDay).append("-")
                .append(mYear).append(" "));


}

/* the callback received when the user “sets” the date in the dialog for the start date function */

 private DatePickerDialog.OnDateSetListener mDateSetListener =
            new DatePickerDialog.OnDateSetListener() {

            public void onDateSet(DatePicker view, int year, 
                                  int monthOfYear, int dayOfMonth) {
                mYear = year;
                mMonth = monthOfYear;
                mDay = dayOfMonth;
                updateStartDisplay();
            }
        };

@Override
protected Dialog onCreateDialog(int id) {
    switch (id) {
    case START_DATE_DIALOG_ID:
        return new DatePickerDialog(this,
                    mDateSetListener,
                    mYear, mMonth, mDay);
    }
    return null;
}
/* the callback received when the user "sets" the date in the dialog for the end date function  */

private DatePickerDialog.OnDateSetListener endDateSetListener =
        new DatePickerDialog.OnDateSetListener() {

            public void onDateSet(DatePicker view, int year, 
                                  int monthOfYear, int dayOfMonth) {
                mYear = year;
                mMonth = monthOfYear;
                mDay = dayOfMonth;
                updateStartDisplay();
            }
        };

protected Dialog onCreateDialog1(int id) {
    switch (id) {
    case END_DATE_DIALOG_ID:
        return new DatePickerDialog(this,
                    endDateSetListener,
                    mYear, mMonth, mDay);
    }
    return null;
}

}

Please advise on the changes required for the code.

Answer 1

You need to make 2 separate DatePicker Dialogs

Make 2 Listeners

int from_year, from_month, from_day,to_year, to_month, to_day; //initialize them to current date in onStart()/onCreate()
DatePickerDialog.OnDateSetListener from_dateListener,to_dateListener;

Implement them…

         from_dateListener = new OnDateSetListener(){

            public void onDateSet(DatePicker arg0, int arg1, int arg2, int arg3) {

                          ...

                }
            }

        };
        to_dateListener = new OnDateSetListener(){
            public void onDateSet(DatePicker arg0, int arg1, int arg2, int arg3) {
                .....
            }
        };

Create Seperate Dialogs for both of them

int DATE_PICKER_TO = 0;
int DATE_PICKER_FROM = 1;

@Override
protected Dialog onCreateDialog(int id) {

    switch(id){
        case DATE_PICKER_FROM:
                return new DatePickerDialog(this, from_dateListener, from_year, from_month, from_day); 
            case DATE_PICKER_TO:
                return new DatePickerDialog(this, to_dateListener, to_year, to_month, to_day);
    }
        return null;
}