Ndtyjky

I have an app that has three fragments. On the second fragment I have a time picker and I want to feed the value selected on this time picker to the main activity.

I believe there is an error in this section of code as it builds and deploys to my device, but crashes on opening.

@Override

        protected void onCreate(Bundle savedInstanceState) {

            super.onCreate(savedInstanceState);

            setContentView(R.layout.activity_main);



            mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());



            // Set up the ViewPager with the sections adapter.

            mViewPager = (ViewPager) findViewById(R.id.container);

            mViewPager.setAdapter(mSectionsPagerAdapter);





//In debugging here is the section of code that causes the app to no longer run



            timePicker1 = (TimePicker) findViewById(R.id.alarmTimePickerStart);

            time = (TextView) findViewById(R.id.textView3);

            calendar = Calendar.getInstance();



            int hour = calendar.get(Calendar.HOUR_OF_DAY);

            int min = calendar.get(Calendar.MINUTE);

            showTime(hour, min);

        }



        public void setTime(View view) {

            int hour = timePicker1.getCurrentHour();

            int min = timePicker1.getCurrentMinute();

            showTime(hour, min);

        }



        public void showTime(int hour, int min) {

            if (hour == 0) {

                hour += 12;

                format = "AM";

            } else if (hour == 12) {

                format = "PM";

            } else if (hour > 12) {

                hour -= 12;

                format = "PM";

            } else {

                format = "AM";

            }



            time.setText(new StringBuilder().append(hour).append(" : ").append(min)

                    .append(" ").append(format));





        }

Am I putting this code in the wrong java file? I figured it would be a main activity command as the value of time picked needs to be global to the application and must be saved during termination of the app.

Here is the error log:

E/AndroidRuntime: FATAL EXCEPTION: main

    Process: io.mindfulmotivation.mindfulmotivation, PID: 31814

    java.lang.RuntimeException: Unable to start activity ComponentInfo{io.mindfulmotivation.mindfulmotivation/io.mindfulmotivation.mindfulmotivation.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.setText(java.lang.CharSequence)' on a null object reference

        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2679)

        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2740)

        at android.app.ActivityThread.-wrap12(ActivityThread.java)

        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1487)

        at android.os.Handler.dispatchMessage(Handler.java:102)

        at android.os.Looper.loop(Looper.java:154)

        at android.app.ActivityThread.main(ActivityThread.java:6164)

        at java.lang.reflect.Method.invoke(Native Method)

        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:888)

        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:778)

     Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.setText(java.lang.CharSequence)' on a null object reference

        at io.mindfulmotivation.mindfulmotivation.MainActivity.showTime(MainActivity.java:84)

        at io.mindfulmotivation.mindfulmotivation.MainActivity.onCreate(MainActivity.java:62)

        at android.app.Activity.performCreate(Activity.java:6720)

        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1119)

        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2632)

        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2740) 

        at android.app.ActivityThread.-wrap12(ActivityThread.java) 

        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1487) 

        at android.os.Handler.dispatchMessage(Handler.java:102) 

        at android.os.Looper.loop(Looper.java:154) 

        at android.app.ActivityThread.main(ActivityThread.java:6164) 

        at java.lang.reflect.Method.invoke(Native Method) 

        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:888) 

        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:778)

This is happening because you are trying to set text in a TextView which is not in the MainActivity.

time = (TextView) findViewById(R.id.textView3);

And

time.setText(new StringBuilder().append(hour).append(" : ").append(min)

                    .append(" ").append(format));

Make sure R.id.textView3 is in the MainActivity, not in any Fragment.