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General Discussion

jason zheng
jason zheng
1,520 Points

Need help, my emulator keep telling me " unfortunately, crystal ball has stopped. Idk what i did wrong

here is my code.

package com.example.crystalball;

import java.util.Random;

import android.os.Bundle; import android.support.v4.app.Fragment; import android.support.v7.app.ActionBarActivity; import android.view.LayoutInflater; import android.view.Menu; import android.view.MenuItem; import android.view.View; import android.view.ViewGroup; import android.widget.Button; import android.widget.TextView;

public class MainActivity extends ActionBarActivity {

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

final TextView answerLabel =(TextView)findViewById(R.id.textView2); Button answers =(Button)findViewById(R.id.button1); answers.setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View arg0) {
    String [] answers = {
            "It is certain",
            "It is decidely so",
            " All sign say Yes",
            " My reply is no",
            "It is not there yet",
            "Better not tell you yet",
            "cant answer now"
    };

    String answer = " ";
    Random Generator = new Random ();
    int randonNumber = Generator.nextInt(answers.length);

    answer = answers[randonNumber];
    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); } }

XTML

<TextView android:id="@+id/textView2" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_centerHorizontal="true" android:layout_centerVertical="true" />

<Button android:id="@+id/button1" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_below="@+id/textView2" android:layout_centerHorizontal="true" android:layout_marginTop="16dp" android:text="Enlighten Me" />

Logcat

06-05 02:30:45.476: D/gralloc_goldfish(1107): Emulator without GPU emulation detected. 06-05 02:30:52.396: I/Choreographer(1107): Skipped 43 frames! The application may be doing too much work on its main thread. 06-05 02:32:08.656: D/AndroidRuntime(1152): Shutting down VM 06-05 02:32:08.656: W/dalvikvm(1152): threadid=1: thread exiting with uncaught exception (group=0xb2aebba8) 06-05 02:32:08.666: E/AndroidRuntime(1152): FATAL EXCEPTION: main 06-05 02:32:08.666: E/AndroidRuntime(1152): Process: com.example.crystalball, PID: 1152 06-05 02:32:08.666: E/AndroidRuntime(1152): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.crystalball/com.example.crystalball.MainActivity}: java.lang.NullPointerException 06-05 02:32:08.666: E/AndroidRuntime(1152): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195) 06-05 02:32:08.666: E/AndroidRuntime(1152): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245) 06-05 02:32:08.666: E/AndroidRuntime(1152): at android.app.ActivityThread.access$800(ActivityThread.java:135) 06-05 02:32:08.666: E/AndroidRuntime(1152): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196) 06-05 02:32:08.666: E/AndroidRuntime(1152): at android.os.Handler.dispatchMessage(Handler.java:102) 06-05 02:32:08.666: E/AndroidRuntime(1152): at android.os.Looper.loop(Looper.java:136) 06-05 02:32:08.666: E/AndroidRuntime(1152): at android.app.ActivityThread.main(ActivityThread.java:5017) 06-05 02:32:08.666: E/AndroidRuntime(1152): at java.lang.reflect.Method.invokeNative(Native Method) 06-05 02:32:08.666: E/AndroidRuntime(1152): at java.lang.reflect.Method.invoke(Method.java:515) 06-05 02:32:08.666: E/AndroidRuntime(1152): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779) 06-05 02:32:08.666: E/AndroidRuntime(1152): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595) 06-05 02:32:08.666: E/AndroidRuntime(1152): at dalvik.system.NativeStart.main(Native Method) 06-05 02:32:08.666: E/AndroidRuntime(1152): Caused by: java.lang.NullPointerException 06-05 02:32:08.666: E/AndroidRuntime(1152): at com.example.crystalball.MainActivity.onCreate(MainActivity.java:31) 06-05 02:32:08.666: E/AndroidRuntime(1152): at android.app.Activity.performCreate(Activity.java:5231) 06-05 02:32:08.666: E/AndroidRuntime(1152): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087) 06-05 02:32:08.666: E/AndroidRuntime(1152): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159) 06-05 02:32:08.666: E/AndroidRuntime(1152): ... 11 more 06-05 02:32:24.396: I/Process(1152): Sending signal. PID: 1152 SIG: 9 06-05 02:33:23.326: D/AndroidRuntime(1199): Shutting down VM 06-05 02:33:23.326: W/dalvikvm(1199): threadid=1: thread exiting with uncaught exception (group=0xb2aebba8) 06-05 02:33:23.336: E/AndroidRuntime(1199): FATAL EXCEPTION: main 06-05 02:33:23.336: E/AndroidRuntime(1199): Process: com.example.crystalball, PID: 1199 06-05 02:33:23.336: E/AndroidRuntime(1199): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.crystalball/com.example.crystalball.MainActivity}: java.lang.NullPointerException 06-05 02:33:23.336: E/AndroidRuntime(1199): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195) 06-05 02:33:23.336: E/AndroidRuntime(1199): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245) 06-05 02:33:23.336: E/AndroidRuntime(1199): at android.app.ActivityThread.access$800(ActivityThread.java:135) 06-05 02:33:23.336: E/AndroidRuntime(1199): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196) 06-05 02:33:23.336: E/AndroidRuntime(1199): at android.os.Handler.dispatchMessage(Handler.java:102) 06-05 02:33:23.336: E/AndroidRuntime(1199): at android.os.Looper.loop(Looper.java:136) 06-05 02:33:23.336: E/AndroidRuntime(1199): at android.app.ActivityThread.main(ActivityThread.java:5017) 06-05 02:33:23.336: E/AndroidRuntime(1199): at java.lang.reflect.Method.invokeNative(Native Method) 06-05 02:33:23.336: E/AndroidRuntime(1199): at java.lang.reflect.Method.invoke(Method.java:515) 06-05 02:33:23.336: E/AndroidRuntime(1199): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779) 06-05 02:33:23.336: E/AndroidRuntime(1199): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595) 06-05 02:33:23.336: E/AndroidRuntime(1199): at dalvik.system.NativeStart.main(Native Method) 06-05 02:33:23.336: E/AndroidRuntime(1199): Caused by: java.lang.NullPointerException 06-05 02:33:23.336: E/AndroidRuntime(1199): at com.example.crystalball.MainActivity.onCreate(MainActivity.java:31) 06-05 02:33:23.336: E/AndroidRuntime(1199): at android.app.Activity.performCreate(Activity.java:5231) 06-05 02:33:23.336: E/AndroidRuntime(1199): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087) 06-05 02:33:23.336: E/AndroidRuntime(1199): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159) 06-05 02:33:23.336: E/AndroidRuntime(1199): ... 11 more 06-05 02:33:29.066: I/Process(1199): Sending signal. PID: 1199 SIG: 9 06-05 02:38:16.366: D/AndroidRuntime(1247): Shutting down VM 06-05 02:38:16.366: W/dalvikvm(1247): threadid=1: thread exiting with uncaught exception (group=0xb2aebba8) 06-05 02:38:16.376: E/AndroidRuntime(1247): FATAL EXCEPTION: main 06-05 02:38:16.376: E/AndroidRuntime(1247): Process: com.example.crystalball, PID: 1247 06-05 02:38:16.376: E/AndroidRuntime(1247): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.crystalball/com.example.crystalball.MainActivity}: java.lang.NullPointerException 06-05 02:38:16.376: E/AndroidRuntime(1247): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195) 06-05 02:38:16.376: E/AndroidRuntime(1247): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245) 06-05 02:38:16.376: E/AndroidRuntime(1247): at android.app.ActivityThread.access$800(ActivityThread.java:135) 06-05 02:38:16.376: E/AndroidRuntime(1247): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196) 06-05 02:38:16.376: E/AndroidRuntime(1247): at android.os.Handler.dispatchMessage(Handler.java:102) 06-05 02:38:16.376: E/AndroidRuntime(1247): at android.os.Looper.loop(Looper.java:136) 06-05 02:38:16.376: E/AndroidRuntime(1247): at android.app.ActivityThread.main(ActivityThread.java:5017) 06-05 02:38:16.376: E/AndroidRuntime(1247): at java.lang.reflect.Method.invokeNative(Native Method) 06-05 02:38:16.376: E/AndroidRuntime(1247): at java.lang.reflect.Method.invoke(Method.java:515) 06-05 02:38:16.376: E/AndroidRuntime(1247): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779) 06-05 02:38:16.376: E/AndroidRuntime(1247): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595) 06-05 02:38:16.376: E/AndroidRuntime(1247): at dalvik.system.NativeStart.main(Native Method) 06-05 02:38:16.376: E/AndroidRuntime(1247): Caused by: java.lang.NullPointerException 06-05 02:38:16.376: E/AndroidRuntime(1247): at com.example.crystalball.MainActivity.onCreate(MainActivity.java:31) 06-05 02:38:16.376: E/AndroidRuntime(1247): at android.app.Activity.performCreate(Activity.java:5231) 06-05 02:38:16.376: E/AndroidRuntime(1247): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087) 06-05 02:38:16.376: E/AndroidRuntime(1247): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159) 06-05 02:38:16.376: E/AndroidRuntime(1247): ... 11 more 06-05 02:40:40.296: D/AndroidRuntime(1291): Shutting down VM 06-05 02:40:40.296: W/dalvikvm(1291): threadid=1: thread exiting with uncaught exception (group=0xb2aebba8) 06-05 02:40:40.306: E/AndroidRuntime(1291): FATAL EXCEPTION: main 06-05 02:40:40.306: E/AndroidRuntime(1291): Process: com.example.crystalball, PID: 1291 06-05 02:40:40.306: E/AndroidRuntime(1291): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.crystalball/com.example.crystalball.MainActivity}: java.lang.NullPointerException 06-05 02:40:40.306: E/AndroidRuntime(1291): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195) 06-05 02:40:40.306: E/AndroidRuntime(1291): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245) 06-05 02:40:40.306: E/AndroidRuntime(1291): at android.app.ActivityThread.access$800(ActivityThread.java:135) 06-05 02:40:40.306: E/AndroidRuntime(1291): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196) 06-05 02:40:40.306: E/AndroidRuntime(1291): at android.os.Handler.dispatchMessage(Handler.java:102) 06-05 02:40:40.306: E/AndroidRuntime(1291): at android.os.Looper.loop(Looper.java:136) 06-05 02:40:40.306: E/AndroidRuntime(1291): at android.app.ActivityThread.main(ActivityThread.java:5017) 06-05 02:40:40.306: E/AndroidRuntime(1291): at java.lang.reflect.Method.invokeNative(Native Method) 06-05 02:40:40.306: E/AndroidRuntime(1291): at java.lang.reflect.Method.invoke(Method.java:515) 06-05 02:40:40.306: E/AndroidRuntime(1291): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779) 06-05 02:40:40.306: E/AndroidRuntime(1291): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595) 06-05 02:40:40.306: E/AndroidRuntime(1291): at dalvik.system.NativeStart.main(Native Method) 06-05 02:40:40.306: E/AndroidRuntime(1291): Caused by: java.lang.NullPointerException 06-05 02:40:40.306: E/AndroidRuntime(1291): at com.example.crystalball.MainActivity.onCreate(MainActivity.java:31) 06-05 02:40:40.306: E/AndroidRuntime(1291): at android.app.Activity.performCreate(Activity.java:5231) 06-05 02:40:40.306: E/AndroidRuntime(1291): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087) 06-05 02:40:40.306: E/AndroidRuntime(1291): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159) 06-05 02:40:40.306: E/AndroidRuntime(1291): ... 11 more 06-05 02:40:53.716: I/Process(1291): Sending signal. PID: 1291 SIG: 9 06-05 02:41:19.226: D/gralloc_goldfish(1339): Emulator without GPU emulation detected. 06-05 02:43:14.516: D/AndroidRuntime(1383): Shutting down VM 06-05 02:43:14.516: W/dalvikvm(1383): threadid=1: thread exiting with uncaught exception (group=0xb2aebba8) 06-05 02:43:14.526: E/AndroidRuntime(1383): FATAL EXCEPTION: main 06-05 02:43:14.526: E/AndroidRuntime(1383): Process: com.example.crystalball, PID: 1383 06-05 02:43:14.526: E/AndroidRuntime(1383): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.crystalball/com.example.crystalball.MainActivity}: java.lang.NullPointerException 06-05 02:43:14.526: E/AndroidRuntime(1383): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195) 06-05 02:43:14.526: E/AndroidRuntime(1383): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245) 06-05 02:43:14.526: E/AndroidRuntime(1383): at android.app.ActivityThread.access$800(ActivityThread.java:135) 06-05 02:43:14.526: E/AndroidRuntime(1383): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196) 06-05 02:43:14.526: E/AndroidRuntime(1383): at android.os.Handler.dispatchMessage(Handler.java:102) 06-05 02:43:14.526: E/AndroidRuntime(1383): at android.os.Looper.loop(Looper.java:136) 06-05 02:43:14.526: E/AndroidRuntime(1383): at android.app.ActivityThread.main(ActivityThread.java:5017) 06-05 02:43:14.526: E/AndroidRuntime(1383): at java.lang.reflect.Method.invokeNative(Native Method) 06-05 02:43:14.526: E/AndroidRuntime(1383): at java.lang.reflect.Method.invoke(Method.java:515) 06-05 02:43:14.526: E/AndroidRuntime(1383): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779) 06-05 02:43:14.526: E/AndroidRuntime(1383): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595) 06-05 02:43:14.526: E/AndroidRuntime(1383): at dalvik.system.NativeStart.main(Native Method) 06-05 02:43:14.526: E/AndroidRuntime(1383): Caused by: java.lang.NullPointerException 06-05 02:43:14.526: E/AndroidRuntime(1383): at com.example.crystalball.MainActivity.onCreate(MainActivity.java:31) 06-05 02:43:14.526: E/AndroidRuntime(1383): at android.app.Activity.performCreate(Activity.java:5231) 06-05 02:43:14.526: E/AndroidRuntime(1383): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087) 06-05 02:43:14.526: E/AndroidRuntime(1383): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159) 06-05 02:43:14.526: E/AndroidRuntime(1383): ... 11 more 06-05 02:45:48.016: D/AndroidRuntime(1427): Shutting down VM 06-05 02:45:48.016: W/dalvikvm(1427): threadid=1: thread exiting with uncaught exception (group=0xb2aebba8) 06-05 02:45:48.026: E/AndroidRuntime(1427): FATAL EXCEPTION: main 06-05 02:45:48.026: E/AndroidRuntime(1427): Process: com.example.crystalball, PID: 1427 06-05 02:45:48.026: E/AndroidRuntime(1427): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.crystalball/com.example.crystalball.MainActivity}: java.lang.NullPointerException 06-05 02:45:48.026: E/AndroidRuntime(1427): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195) 06-05 02:45:48.026: E/AndroidRuntime(1427): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245) 06-05 02:45:48.026: E/AndroidRuntime(1427): at android.app.ActivityThread.access$800(ActivityThread.java:135) 06-05 02:45:48.026: E/AndroidRuntime(1427): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196) 06-05 02:45:48.026: E/AndroidRuntime(1427): at android.os.Handler.dispatchMessage(Handler.java:102) 06-05 02:45:48.026: E/AndroidRuntime(1427): at android.os.Looper.loop(Looper.java:136) 06-05 02:45:48.026: E/AndroidRuntime(1427): at android.app.ActivityThread.main(ActivityThread.java:5017) 06-05 02:45:48.026: E/AndroidRuntime(1427): at java.lang.reflect.Method.invokeNative(Native Method) 06-05 02:45:48.026: E/AndroidRuntime(1427): at java.lang.reflect.Method.invoke(Method.java:515) 06-05 02:45:48.026: E/AndroidRuntime(1427): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779) 06-05 02:45:48.026: E/AndroidRuntime(1427): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595) 06-05 02:45:48.026: E/AndroidRuntime(1427): at dalvik.system.NativeStart.main(Native Method) 06-05 02:45:48.026: E/AndroidRuntime(1427): Caused by: java.lang.NullPointerException 06-05 02:45:48.026: E/AndroidRuntime(1427): at com.example.crystalball.MainActivity.onCreate(MainActivity.java:29) 06-05 02:45:48.026: E/AndroidRuntime(1427): at android.app.Activity.performCreate(Activity.java:5231) 06-05 02:45:48.026: E/AndroidRuntime(1427): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087) 06-05 02:45:48.026: E/AndroidRuntime(1427): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159) 06-05 02:45:48.026: E/AndroidRuntime(1427): ... 11 more