Fun Facts has stopepd

Did you check the logs or insert any println statements with console output that could possibly help you debug the issue?

This is what the log says:

Unable to start activity ComponentInfo{com.reisventures.funfacts/com.reisventures.funfacts.FunFactsActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.Button.setOnClickListener(android.view.View$OnClickListener)' on a null object reference

All my code is the same as in the video! :/

From your error statement it looks like a button has not been initialized correctly. Can you post your code?

Hey Jon Thanks a lot in advance!

Code:

package com.reisventures.funfacts;

import android.app.Activity; import android.os.Bundle; import android.view.Menu; import android.view.MenuItem; import android.view.View; import android.widget.Button; import android.widget.TextView;

public class FunFactsActivity extends Activity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_fun_facts);

    final TextView factLabel = (TextView) findViewById(R.id.factTextView);
    Button showFactButton = (Button) findViewById(R.id.showFactButton);
    View.OnClickListener listener = new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            String fact = "Ostriches can run faster than horses.";
            factLabel.setText(fact);
        }
    };

    showFactButton.setOnClickListener(listener);

Hey Jon,

You tipped me! I went to the xml file and saw that the id was different for the button! I didn't know capital letters metter! ;)

Anyway, I'm really struggling to understand why we need to use these 2 lines of code. I know a bit of VBA, and it is more straight forward!

I get the part of the click listener, basically I'm creating and action. I don't understand why we need the following part of the code and why we relate it to the id's we've created for the layouts:

Code:

final TextView factLabel = (TextView) findViewById(R.id.factTextView);

Button showFactButton = (Button) findViewById(R.id.showFactButton);

Thanks in advance.

Duarte

Thanks a lot! It is much more clear now!

The process of learning this things is really frustrating! While I (now) understand the code and what it does, I would never be able to replicate it by myself! :)

Cheers,

Duarte