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Android Build a Simple Android App (2014) Basic Android Programming Adding the onClick() Method

Josh Myers
Josh Myers
3,203 Points

Error running Fun Facts app

When I ran the fun facts app for the first time it said "Unfortunately Fun Fact has stopped" I looked through the error log, but can't make sense of it. This is what it gave me:

1-03 00:28:57.430 1000-1000/com.example.josh.funfact E/AndroidRuntime﹕ FATAL EXCEPTION: main Process: com.example.josh.funfact, PID: 1000 java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.josh.funfact/com.example.josh.funfact.FunFactsActivity}: java.lang.NullPointerException at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245) at android.app.ActivityThread.access$800(ActivityThread.java:135) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196) at android.os.Handler.dispatchMessage(Handler.java:102) at android.os.Looper.loop(Looper.java:136) at android.app.ActivityThread.main(ActivityThread.java:5017) at java.lang.reflect.Method.invokeNative(Native Method) at java.lang.reflect.Method.invoke(Method.java:515) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595) at dalvik.system.NativeStart.main(Native Method) Caused by: java.lang.NullPointerException at com.example.josh.funfact.FunFactsActivity.onCreate(FunFactsActivity.java:31) at android.app.Activity.performCreate(Activity.java:5231) at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087) at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159)             at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)             at android.app.ActivityThread.access$800(ActivityThread.java:135)             at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)             at android.os.Handler.dispatchMessage(Handler.java:102)             at android.os.Looper.loop(Looper.java:136)             at android.app.ActivityThread.main(ActivityThread.java:5017)             at java.lang.reflect.Method.invokeNative(Native Method)             at java.lang.reflect.Method.invoke(Method.java:515)             at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)             at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)             at dalvik.system.NativeStart.main(Native Method)

I just pasted the red lines in the error log...

Any suggestions?

2 Answers

Jaroslav Vankat
Jaroslav Vankat
12,054 Points

Seems to be a NullPointerException, try posting the whole code of your FunFactsActivity.

Josh Myers
Josh Myers
3,203 Points

Ok, here it is. Thanks!

package com.example.josh.funfact;

import android.app.Activity; import android.os.Bundle; import android.view.ContextMenu; 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);

    //Declare our view variables and assign them the Views from the layout file
    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) {
        // The button was clicked, so update the fact label with a new fact
            String fact = "Ostriches can run faster than horses.";
            factLabel.setText(fact);
        }
    };
   showFactButton.setOnClickListener(listener);

}


@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.fun_facts, 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);
}

}

Jaroslav Vankat
Jaroslav Vankat
12,054 Points

Seems to be ok, try declaring the views as member variables and assigning the views to them:

public class FunFactsActivity extends Activity {

Button mShowFactButton;
TextView mFactLabel;

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

    mFactLabel = (TextView) findViewById(R.id.factTextView);
    Button showFactButton = (Button) findViewById(R.id.showFactButton);
   /** and so on */
}

The problem might be setting the mFactLabel as final, but don't no right now and no time for trying.