crystal ball has stopped working.

Hi Giusweppe,

Could you post the contents of LogCat (there should be a 'LogCat' tab at the bottom of Eclipse which displays the error) here along with your MainActivity.java and activity_main.xml?

Don't forget to use the Markdown formatting below so the code is easier to read :)

1. LogCat

. 06-10 00:21:14.902: D/AndroidRuntime(1114): Shutting down VM 06-10 00:21:14.902: W/dalvikvm(1114): threadid=1: thread exiting with uncaught exception (group=0xb1b0fba8) 06-10 00:21:14.922: E/AndroidRuntime(1114): FATAL EXCEPTION: main 06-10 00:21:14.922: E/AndroidRuntime(1114): Process: com.example.crystalball, PID: 1114 06-10 00:21:14.922: E/AndroidRuntime(1114): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.crystalball/com.example.crystalball.MainActivity}: java.lang.NullPointerException 06-10 00:21:14.922: E/AndroidRuntime(1114): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195) 06-10 00:21:14.922: E/AndroidRuntime(1114): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245) 06-10 00:21:14.922: E/AndroidRuntime(1114): at android.app.ActivityThread.access$800(ActivityThread.java:135) 06-10 00:21:14.922: E/AndroidRuntime(1114): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196) 06-10 00:21:14.922: E/AndroidRuntime(1114): at android.os.Handler.dispatchMessage(Handler.java:102) 06-10 00:21:14.922: E/AndroidRuntime(1114): at android.os.Looper.loop(Looper.java:136) 06-10 00:21:14.922: E/AndroidRuntime(1114): at android.app.ActivityThread.main(ActivityThread.java:5017) 06-10 00:21:14.922: E/AndroidRuntime(1114): at java.lang.reflect.Method.invokeNative(Native Method) 06-10 00:21:14.922: E/AndroidRuntime(1114): at java.lang.reflect.Method.invoke(Method.java:515) 06-10 00:21:14.922: E/AndroidRuntime(1114): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779) 06-10 00:21:14.922: E/AndroidRuntime(1114): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595) 06-10 00:21:14.922: E/AndroidRuntime(1114): at dalvik.system.NativeStart.main(Native Method) 06-10 00:21:14.922: E/AndroidRuntime(1114): Caused by: java.lang.NullPointerException 06-10 00:21:14.922: E/AndroidRuntime(1114): at com.example.crystalball.MainActivity.onCreate(MainActivity.java:23) 06-10 00:21:14.922: E/AndroidRuntime(1114): at android.app.Activity.performCreate(Activity.java:5231) 06-10 00:21:14.922: E/AndroidRuntime(1114): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087) 06-10 00:21:14.922: E/AndroidRuntime(1114): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159)

1. ActivityMain.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:paddingBottom="@dimen/activity_vertical_margin" android:paddingLeft="@dimen/activity_horizontal_margin" android:paddingRight="@dimen/activity_horizontal_margin" android:paddingTop="@dimen/activity_vertical_margin" tools:context="com.example.crystalball.MainActivity$PlaceholderFragment" >

<TextView
    android:id="@+id/textView1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_centerHorizontal="true"
    android:layout_centerVertical="true"
    android:textSize="32sp" />

<Button
    android:id="@+id/button1"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_below="@+id/textView1"
    android:layout_centerHorizontal="true"
    android:text="Enlighten Me!" />

</RelativeLayout>

1. MainActivity.java

package com.example.crystalball;

import android.os.Bundle; import android.support.v7.app.ActionBarActivity; import android.view.Menu; import android.view.MenuItem; import android.view.View; import android.widget.Button; import android.widget.TextView;

public class MainActivity extends ActionBarActivity {

@SuppressWarnings("null")
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    // Declare Our View Variables and assign them the views from the layout file
    final TextView answerLabel = (TextView) findViewById(R.id.textView1);
    Button getAnswerButton = null;

    getAnswerButton.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            // The Button was Clicked, so update the answer label with an answer
            String answer = "Yes";
            answerLabel.setText(answer);
        }
    });
}


@Override
public boolean onCreateOptionsMenu(Menu menu) {

    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();
    if (id == R.id.action_settings) {
        return true;
    }
    return super.onOptionsItemSelected(item);
}

}

I hope that is what you meant by markdown. thank you for taking the time to help :) i followed the instructions step by step. dont know where im going wrong.

thankyou so much for helping me :) i understand what you mean by null now :)