LoginActivity.java ~ OnClickListener > signupText EXPLOSION

Could you post the actual error log you're getting? That code looks fine.

Basically what I have determined is I have two files for a specific process i.e. "activity_sign_up.xml" and "fragment_sign_up.xml". I am only able to build the graphical layout in the fragment xml and when I run the app it crashes with the "NullPointerException." What I have determined is if I copy all of the xml code from the fragment and past it into the "Activity" XML between the <FrameLayout><FrameLayout/> then comment out:

//@Override //public View onCreateView(LayoutInflater inflater, ViewGroup container, // Bundle savedInstanceState) { // View rootView = inflater.inflate(R.layout.fragment_login, // container, false); // return rootView; //}

Then everything works.

So what I need help with then is how to make the app work with the "fragment.xml" that are generated when I create a new activity.

I don't have an error log for it any longer but I had the same thing happen when I got further along with activity_sign_up.xml and fragment_sign_up.xml so here is the log for that so you can see what the error is like.

LOG: 04-17 13:40:54.996: W/dalvikvm(1102): threadid=1: thread exiting with uncaught exception (group=0xb3a3aba8) 04-17 13:40:55.026: E/AndroidRuntime(1102): FATAL EXCEPTION: main 04-17 13:40:55.026: E/AndroidRuntime(1102): Process: com.appmanimal.izuto_chat, PID: 1102 04-17 13:40:55.026: E/AndroidRuntime(1102): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.appmanimal.izuto_chat/com.appmanimal.izuto_chat.SignUpActivity}: java.lang.NullPointerException 04-17 13:40:55.026: E/AndroidRuntime(1102): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195) 04-17 13:40:55.026: E/AndroidRuntime(1102): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245) 04-17 13:40:55.026: E/AndroidRuntime(1102): at android.app.ActivityThread.access$800(ActivityThread.java:135) 04-17 13:40:55.026: E/AndroidRuntime(1102): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196) 04-17 13:40:55.026: E/AndroidRuntime(1102): at android.os.Handler.dispatchMessage(Handler.java:102) 04-17 13:40:55.026: E/AndroidRuntime(1102): at android.os.Looper.loop(Looper.java:136) 04-17 13:40:55.026: E/AndroidRuntime(1102): at android.app.ActivityThread.main(ActivityThread.java:5017) 04-17 13:40:55.026: E/AndroidRuntime(1102): at java.lang.reflect.Method.invokeNative(Native Method) 04-17 13:40:55.026: E/AndroidRuntime(1102): at java.lang.reflect.Method.invoke(Method.java:515) 04-17 13:40:55.026: E/AndroidRuntime(1102): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779) 04-17 13:40:55.026: E/AndroidRuntime(1102): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595) 04-17 13:40:55.026: E/AndroidRuntime(1102): at dalvik.system.NativeStart.main(Native Method) 04-17 13:40:55.026: E/AndroidRuntime(1102): Caused by: java.lang.NullPointerException 04-17 13:40:55.026: E/AndroidRuntime(1102): at com.appmanimal.izuto_chat.SignUpActivity.onCreate(SignUpActivity.java:31)

Ok, that says this error is from SignUpActivity line 31, so could you post that region of code?

mSignUpButton.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            String username = mUsername.getText().toString();
            String password = mPassword.getText().toString();
            String email = mEmail.getText().toString();

            username = username.trim();
            password = password.trim();
            email = email.trim();

            if (username.isEmpty() || password.isEmpty() || email.isEmpty()) {
                AlertDialog.Builder builder = new AlertDialog.Builder(SignUpActivity.this);
                builder.setMessage(R.string.signup_error_message)
                    .setTitle(R.string.signup_error_title)
                    .setPositiveButton(android.R.string.ok, null);
                AlertDialog dialog = builder.create();
                dialog.show();
            }
            else {
                // Create a new user
            }

        }

There aren't any numbers in the code you just pasted, so I'm not sure where line 31 is, but this is the only possible issue I can think of.

The layout that you are using in your onCreate is not the right one. You may accidentally have put the layout information (TextViews, Buttons, etc) in fragment_signup.xml instead of activity_signup.xml. Therefore when the activity is loaded and your code starts looking for id's in the xml that aren't there, any information you try to pull from non-existent fields will throw a null pointer exception. -- I'm referring to mEmail, mUsername, and mPassword

like -- mUsername = (EditText) findViewById(R.id.usernameField); // this might work here, but when you try //String username = mUsername.getText().toString(); // you get a null pointer exception because youre pulling from the wrong (non-existent) field

hopefully that helps.

Thanks for trying to help Marco. Line 31 is mSignUpButton.setOnClickListener(new View.OnClickListener() {

I fixed the problem with a work around by coping all of the xml code from the "fragment" and pasted it into the "Activity" XML between the "FrameLayout" flags and then in the java code I commented out:

// File Name: LoginActivity.java @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { View rootView = inflater.inflate(R.layout.fragment_login, container, false); return rootView; }

// File Name: SignUpActivity.java if (savedInstanceState == null) { getFragmentManager().beginTransaction() .add(R.id.container, new PlaceholderFragment()).commit(); }

public static class PlaceholderFragment extends Fragment {

    public PlaceholderFragment() {
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.fragment_sign_up,
                container, false);
        return rootView;
    }
}