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POAndroid: Null pointer Exception runtime error
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  1. POAndroid: Null pointer Exception runtime error
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    copied!<p>After I tried to include a menu, a dialog box, and a popup box, I started getting a NullPointerException on startup. I have tried to comment out parts of the code and the progam only works if I comment the class variables and everything below the onCreate method. I would appreciate help in finding what is causing the exception.</p> <pre><code>package com.emailandcontactmanager; import android.app.Activity; import android.app.AlertDialog; import android.content.Context; import android.content.DialogInterface; import android.content.Intent; import android.os.Bundle; import android.view.LayoutInflater; import android.view.Menu; import android.view.MenuInflater; import android.view.MenuItem; import android.view.View; import android.view.View.OnClickListener; import android.widget.Button; import android.widget.EditText; import android.widget.LinearLayout; import android.widget.PopupWindow; public class MainActivity extends Activity{ EditText title = (EditText) findViewById(R.id.txtTitle); EditText body = (EditText) findViewById(R.id.txtBody); View layout = (View) findViewById(R.layout.main); /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); Button btnSendMenu = (Button) findViewById(R.id.btnSendMenu); btnSendMenu.setOnClickListener(new View.OnClickListener() { public void onClick(View v) { Intent sendMenu = new Intent(v.getContext(), SendMenu.class); startActivity(sendMenu); } }); Button btnContactsMenu = (Button) findViewById(R.id.btnContactsMenu); btnContactsMenu.setOnClickListener(new View.OnClickListener() { public void onClick(View v) { Intent contactsMenu = new Intent(v.getContext(), ContactsMenu.class); startActivity(contactsMenu); } }); Button btnTemplatesMenu = (Button) findViewById(R.id.btnTemplatesMenu); btnTemplatesMenu.setOnClickListener(new View.OnClickListener() { public void onClick(View v) { Intent templatesMenu = new Intent(v.getContext(), TemplatesMenu.class); startActivity(templatesMenu); } }); Button btnTagsMenu = (Button) findViewById(R.id.btnTagsMenu); btnTagsMenu.setOnClickListener(new View.OnClickListener() { public void onClick(View v) { Intent tagsMenu = new Intent(v.getContext(), TagsMenu.class); startActivity(tagsMenu); } }); }//end onCreate DialogInterface.OnClickListener dialogClickListener = new DialogInterface.OnClickListener() { public void onClick(DialogInterface dialog, int which) { switch (which){ case DialogInterface.BUTTON_POSITIVE: finish(); break; case DialogInterface.BUTTON_NEGATIVE: //No button clicked break; } } }; @Override public boolean onCreateOptionsMenu(Menu menu) { MenuInflater inflater = getMenuInflater(); inflater.inflate(R.menu.menu, menu); return true; } @Override public boolean onOptionsItemSelected(MenuItem item) { switch (item.getItemId()) { case R.id.help: showPopup(this); break; case R.id.back: AlertDialog.Builder builder = new AlertDialog.Builder(this); builder.setMessage("Are you sure?").setPositiveButton("Yes", dialogClickListener) .setNegativeButton("No", dialogClickListener).show(); break; } return true; } private void showPopup(final Activity context){ int popupWidth = 200; int popupHeight = 150; // change title and body based on button onHelpClick(layout); LinearLayout viewGroup = (LinearLayout) this.findViewById(R.id.popup); LayoutInflater layoutInfalter = (LayoutInflater) this.getSystemService(Context.LAYOUT_INFLATER_SERVICE); View layout = layoutInfalter.inflate(R.layout.popup, viewGroup); final PopupWindow popup = new PopupWindow(); popup.setContentView(layout); popup.setWidth(popupWidth); popup.setHeight(popupHeight); popup.setFocusable(true); Button close = (Button) layout.findViewById(R.id.close); close.setOnClickListener(new OnClickListener() { public void onClick(View arg0) { // TODO Auto-generated method stub popup.dismiss(); } }); } private void onHelpClick(View v) { switch(v.getId()) { case R.id.btnSendMenu: title.setText("Send Menu"); body.setText("Opens the send menu where you can send an email."); break; case R.id.btnContactsMenu: title.setText("Contacts Menu"); body.setText("Opens the contact menu where you can add a contact or select from a list of" + "recored contacts to edit or view."); break; case R.id.btnTemplatesMenu: title.setText("Templates Menu"); body.setText("Opens the templates menu where you can add an email template or select from a list of" + " recorded templates to edit or view."); break; case R.id.btnTagsMenu: title.setText("Tags Menu"); body.setText("Opens the tags menu where you can add a tag used for sorting contacs, or select from a list of" + " recorded tags to edit or view."); break; default: throw new RuntimeException("Unknown button ID"); } } }//end Class </code></pre> <p>The logcat message is:</p> <pre><code>09-28 15:07:49.205: D/AndroidRuntime(1403): Shutting down VM 09-28 15:07:49.245: W/dalvikvm(1403): threadid=1: thread exiting with uncaught exception (group=0x409961f8) 09-28 15:07:49.365: E/AndroidRuntime(1403): FATAL EXCEPTION: main 09-28 15:07:49.365: E/AndroidRuntime(1403): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.emailandcontactmanager/com.emailandcontactmanager.MainActivity}: java.lang.NullPointerException 09-28 15:07:49.365: E/AndroidRuntime(1403): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1879) 09-28 15:07:49.365: E/AndroidRuntime(1403): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1980) 09-28 15:07:49.365: E/AndroidRuntime(1403): at android.app.ActivityThread.access$600(ActivityThread.java:122) 09-28 15:07:49.365: E/AndroidRuntime(1403): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1146) 09-28 15:07:49.365: E/AndroidRuntime(1403): at android.os.Handler.dispatchMessage(Handler.java:99) 09-28 15:07:49.365: E/AndroidRuntime(1403): at android.os.Looper.loop(Looper.java:137) 09-28 15:07:49.365: E/AndroidRuntime(1403): at android.app.ActivityThread.main(ActivityThread.java:4340) 09-28 15:07:49.365: E/AndroidRuntime(1403): at java.lang.reflect.Method.invokeNative(Native Method) 09-28 15:07:49.365: E/AndroidRuntime(1403): at java.lang.reflect.Method.invoke(Method.java:511) 09-28 15:07:49.365: E/AndroidRuntime(1403): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784) 09-28 15:07:49.365: E/AndroidRuntime(1403): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551) 09-28 15:07:49.365: E/AndroidRuntime(1403): at dalvik.system.NativeStart.main(Native Method) 09-28 15:07:49.365: E/AndroidRuntime(1403): Caused by: java.lang.NullPointerException 09-28 15:07:49.365: E/AndroidRuntime(1403): at android.app.Activity.findViewById(Activity.java:1794) 09-28 15:07:49.365: E/AndroidRuntime(1403): at com.emailandcontactmanager.MainActivity.&lt;init&gt;(MainActivity.java:24) 09-28 15:07:49.365: E/AndroidRuntime(1403): at java.lang.Class.newInstanceImpl(Native Method) 09-28 15:07:49.365: E/AndroidRuntime(1403): at java.lang.Class.newInstance(Class.java:1319) 09-28 15:07:49.365: E/AndroidRuntime(1403): at android.app.Instrumentation.newActivity(Instrumentation.java:1023) 09-28 15:07:49.365: E/AndroidRuntime(1403): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1870) 09-28 15:07:49.365: E/AndroidRuntime(1403): ... 11 more </code></pre> <p>Tell me if you need something else like the xml file codes or something like that. I appreciate any help.</p>
 

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