My FunFacts App is not working

OK thank you now my app is coming up but now when i click the button it has the message again.

Hey again Miles,

I've noticed a few further issues with the ID's that will be causing further crashes.

• Your RelativeLayout does not have an android:id field in the XML file. You should add it and set it to the ID you are referring to in your Java program. In this case, it should be android:id="@+id/relativelayout".
• Your factLabel is called textView2 in the XML code. Use the same steps as in my answer above and make sure that the ID you are referring to is the same in BOTH the XML and Java files.

Hopefully this should fix the rest of the errors but again, if you run into any more then please let me know and provide another Logcat here :)

Ok in the answer above how do I fix both things?

package FactBook;

    import java.util.Random;

/**

• Created by MilesPC on 12/11/2015. */ public class FactBook {

  // Member variable (properties about the object) String[] mFacts = { "Ants stretch when they wake up in the morning.", "Ostriches can run faster than horses.", "Olympic gold medals are actually made mostly of silver.", "You are born with 300 bones; by the time you are an adult you will have 206.", "It takes about 8 minutes for light from the Sun to reach Earth.", "Some bamboo plants can grow almost a meter in just one day.", "The state of Florida is bigger than England.", "Some penguins can leap 2-3 meters out of the water.", "On average, it takes 66 days to form a new habit.", "Mammoths still walked the earth when the Great Pyramid was being built.", "TreeHouse is not actually in a tree"};

  // Method (abilities: things the object can do) public String getFact() {

  String fact = "";
  // Randomly select a fact
  Random randomGenerator = new Random();  //Construct a new random number generator
  int randomNumber = randomGenerator.nextInt(mFacts.length);
  fact = randomNumber + "";
  
  fact = mFacts[randomNumber];
  
  return fact;
  

  } }

this is colorwheel

package com.example.milespc.funfacts;

import android.graphics.Color;

import java.util.Random;

/**

• Created by MilesPC on 1/8/2016. */ public class ColorWheel {

  // Member variable (properties about the object) String[] mColors = { "#39add1", // light blue "#3079ab", // dark blue "#c25975", // mauve "#e15258", // red "#f9845b", // orange "#838cc7", // lavender "#7d669e", // purple "#53bbb4", // aqua "#51b46d", // green "#e0ab18", // mustard "#637a91", // dark gray "#f092b0", // pink "#b7c0c7" // light gray };

  // Method (abilities: things the object can do) public int getColor() {

  String color = "";
  // Randomly select a fact
  Random randomGenerator = new Random();  //Construct a new random number generator
  int randomNumber = randomGenerator.nextInt(mColors.length);
  color = randomNumber + "";
  
  color = mColors[randomNumber];
  int colorAsInt = Color.parseColor(color);
  
  return colorAsInt;
  

  } }

and activityfunfacts.java:

package com.example.milespc.funfacts;

import android.app.Activity; import android.graphics.Color; import android.os.Bundle; import android.support.design.widget.FloatingActionButton; import android.support.design.widget.Snackbar; import android.support.v7.app.AppCompatActivity; import android.support.v7.widget.Toolbar; import android.util.Log; import android.view.View; import android.view.Menu; import android.view.MenuItem; import android.widget.Button; import android.widget.RelativeLayout; import android.widget.TextView; import android.widget.Toast;

import FactBook.FactBook;

public class ActivityFunFacts extends Activity { public static final String TAG = ActivityFunFacts.class.getSimpleName();

private FactBook mFactBook = new FactBook();
private ColorWheel mColorWheel = new ColorWheel();
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_activity_fun_facts);

    // Declare our View variables and assign them the views from the layout file
    final TextView factLabel = (TextView) findViewById(R.id.factTextView);
    final Button showFactButton = (Button) findViewById(R.id.button);
    final RelativeLayout relativeLayout = (RelativeLayout) findViewById(R.id.relativelayout);
    View.OnClickListener listener = new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            String fact = mFactBook.getFact();
            // Update the label with our dynamic fact
            factLabel.setText(fact);

            int color = mColorWheel.getColor();
            relativeLayout.setBackgroundColor(color);
            showFactButton.setTextColor(color);
        }
    };
    showFactButton.setOnClickListener(listener);
    //Toast.makeText(this, "Yay! Our Activity was created!", Toast.LENGTH_LONG).show();
    Log.d(TAG, "We're logging from the onCreate() method!");



}

private class TextView2 {
}

}

Well where exactly do I put android:id="@+id/relativelayout and what is the exact code for fixing the factlable TextView2?

I think this is it: Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.Button.setOnClickListener(android.view.View$OnClickListener)' on a null object reference

this is everything in red: 01-20 12:28:54.309 23410-23410/com.example.milespc.funfacts E/AndroidRuntime: FATAL EXCEPTION: main Process: com.example.milespc.funfacts, PID: 23410 java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.milespc.funfacts/com.example.milespc.funfacts.ActivityFunFacts}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.Button.setOnClickListener(android.view.View$OnClickListener)' on a null object reference at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2331) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2393) at android.app.ActivityThread.access$800(ActivityThread.java:151) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1309) at android.os.Handler.dispatchMessage(Handler.java:102) at android.os.Looper.loop(Looper.java:135) at android.app.ActivityThread.main(ActivityThread.java:5356) at java.lang.reflect.Method.invoke(Native Method) at java.lang.reflect.Method.invoke(Method.java:372) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:908) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:703) Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.Button.setOnClickListener(android.view.View$OnClickListener)' on a null object reference at com.example.milespc.funfacts.ActivityFunFacts.onCreate(ActivityFunFacts.java:47) at android.app.Activity.performCreate(Activity.java:6020) at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1105) at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2284) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2393)  at android.app.ActivityThread.access$800(ActivityThread.java:151)  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1309)  at android.os.Handler.dispatchMessage(Handler.java:102)  at android.os.Looper.loop(Looper.java:135)  at android.app.ActivityThread.main(ActivityThread.java:5356)  at java.lang.reflect.Method.invoke(Native Method)  at java.lang.reflect.Method.invoke(Method.java:372)  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:908)  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:703)

this is the line: showFactButton.setOnClickListener(listener); and no i didn't change the showFactButton to "@+id/button" should I?

Ok now my app is coming up but when i press the button it says "Unfortunately, FunFacts has stopped" do you need my new logcat because it is different.

Hey Miles,

Could you please make sure that where you have an ID like this in your activity_main.xml file:

        <...
            android:id="@+id/exampleID" <------------
            ... />

That where you refer to this specific element in Java, you use the SAME ID as referenced in your XML, like this:

final ExampleElement exampleElement = (ExampleElement) findViewById(R.id.exampleID); <------

The findViewById() method is a Java method that gets a reference to an XML element, so that you can use it in your Java code. Inside the brackets, we tell Java the ID, which is always R.id. followed by the ID you set (exampleID in this example).

to harry i did.

01-22 14:29:11.847 22909-22909/com.example.milespc.funfacts E/AndroidRuntime: FATAL EXCEPTION: main Process: com.example.milespc.funfacts, PID: 22909 java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.setText(java.lang.CharSequence)' on a null object reference at com.example.milespc.funfacts.ActivityFunFacts$1.onClick(ActivityFunFacts.java:42) the code in java now is: factLabel.setText(fact);

also to your second thing i don't know how would i find that out.

Hey Miles,

Can you please supply your updated code files so that we can take a look?

Thanks in advance.

Hey Miles,

For the issue with the fact not changing, take a look at the comment you wrote:

// Update the label with our dynamic factlabel.setText(fact);

You've got this comment but you're not actually setting the factLabel to use the new text - this should be done every time the button is tapped and after we get the new fact.

So, all you need to do is add this line factLabel.setText(fact), I recommend placing it just below your comment. Watch the capitalization though! In your comment, you should have a capital for Label!

As for the issue with the color on the inside staying green, could you please expand on this? What do you mean by "the inside"?

Speak again soon :)

I notice you have an empty RelativeLayout inside the root one that has the same id. Why don't you try removing the empty one and see if that corrects the color issue.

okay, so after i put the fact label and took out the empty relative layout, i ran it, and funfacts stopped and this error came up in logcat: 02-01 13:24:55.618 10646-10646/com.example.milespc.funfacts E/AndroidRuntime: FATAL EXCEPTION: main Process: com.example.milespc.funfacts, PID: 10646 java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.setText(java.lang.CharSequence)' on a null object reference at com.example.milespc.funfacts.ActivityFunFacts$1.onClick(ActivityFunFacts.java:44) at android.view.View.performClick(View.java:4764) at android.view.View$PerformClick.run(View.java:19844) at android.os.Handler.handleCallback(Handler.java:739) at android.os.Handler.dispatchMessage(Handler.java:95) at android.os.Looper.loop(Looper.java:135) at android.app.ActivityThread.main(ActivityThread.java:5356) at java.lang.reflect.Method.invoke(Native Method) at java.lang.reflect.Method.invoke(Method.java:372) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:908) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:703)

What I mean by color on the iside is that the border of the screen changes color but the rectangle inside doesn't change.

I figured out the color problem! now for the text. ;)