My App consists of 2 Activities at
the moment.
.
the MAIN activity with a Gallery View
. a FriendsListActivity with a ListView
When
the user moves away from
the FriendsListActivity with
the back button, and returns
to the MAIN activity
the following error keeps popping up in debug mode.
DalvikVM[localhost:8676] Thread [<1
main] (Suspended (exception
RuntimeException))
ActivityThread.performResumeActivity(IBinder,
boolean) line: 2095
ActivityThread.handleResumeActivity(IBinder,
boolean, boolean) line: 2110
BinderProxy(ActivityThread$H).handleMessage(Message)
line: 954
ActivityThread$H(Handler).dispatchMessage(Message)
line: 99 Looper.loop() line: 123
ActivityThread.main(String[]) line:
3647 Method.invokeNative(Object,
Object[], Class, Class[], Class, int,
boolean) line: not available [native
method] Method.invoke(Object,
Object...) line: 507
ZygoteInit$MethodAndArgsCaller.run()
line: 839 ZygoteInit.main(String[])
line: 597
NativeStart.main(String[]) line: not
available [native method] Thread
[<8 Binder Thread #2] (Running)
Thread [<7 Binder Thread #1]
(Running)
With
the LogCat
03-13 22:01:10.972:
ERROR/AndroidRuntime(1038): FATAL
EXCEPTION: main 03-13 22:01:10.972:
ERROR/AndroidRuntime(1038):
java.lang.RuntimeException: Unable
to
resume activity
{com.package.MAIN/com.package.MAIN.MAIN}:
java.lang.NullPointerException 03-13
22:01:10.972:
ERROR/AndroidRuntime(1038): at
android.app.ActivityThread.performResumeActivity(ActivityThread.java:2095)
03-13 22:01:10.972:
ERROR/AndroidRuntime(1038): at
android.app.ActivityThread.handleResumeActivity(ActivityThread.java:2110)
03-13 22:01:10.972:
ERROR/AndroidRuntime(1038): at
android.app.ActivityThread$H.handleMessage(ActivityThread.java:954)
03-13 22:01:10.972:
ERROR/AndroidRuntime(1038): at
android.os.Handler.dispatchMessage(Handler.java:99)
03-13 22:01:10.972:
ERROR/AndroidRuntime(1038): at
android.os.Looper.loop(Looper.java:123)
03-13 22:01:10.972:
ERROR/AndroidRuntime(1038): at
android.app.ActivityThread.main(ActivityThread.java:3647)
03-13 22:01:10.972:
ERROR/AndroidRuntime(1038): at
java.lang.reflect.Method.invokeNative(Native
Method) 03-13 22:01:10.972:
ERROR/AndroidRuntime(1038): at
java.lang.reflect.Method.invoke(Method.java:507)
03-13 22:01:10.972:
ERROR/AndroidRuntime(1038): at
com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
03-13 22:01:10.972:
ERROR/AndroidRuntime(1038): at
com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
03-13 22:01:10.972:
ERROR/AndroidRuntime(1038): at
dalvik.system.NativeStart.main(Native
Method) 03-13 22:01:10.972:
ERROR/AndroidRuntime(1038): Caused by:
java.lang.NullPointerException 03-13
22:01:10.972:
ERROR/AndroidRuntime(1038): at
com.package.MAIN.MAIN.onResume(MAIN.java:91)
03-13 22:01:10.972:
ERROR/AndroidRuntime(1038): at
android.app.Instrumentation.callActivityOnResume(Instrumentation.java:1149)
03-13 22:01:10.972:
ERROR/AndroidRuntime(1038): at
android.app.Activity.performResume(Activity.java:3833)
03-13 22:01:10.972:
ERROR/AndroidRuntime(1038): at
android.app.ActivityThread.performResumeActivity(ActivityThread.java:2085)
03-13 22:01:10.972:
ERROR/AndroidRuntime(1038): ... 10
more
Further info in
the Variables panel states:
this: ActivityThread
e: NullPointerException
cause: NullPointerException
detailMessage: null
stackTrace: null
r: ActivityThread$ActivityClientRecord
activity: MAIN
detailMessage after one Eclipse Resume: Unable
to resume activity (MAIN)
The code from
the FriendsListActivity looks like this
public class FriendsListActivity extends ListActivity {
// ===========================================================
// Fields
// ===========================================================
private ArrayList<Friend> friends = new ArrayList<Friend>();
private FriendsArrayAdapter friendsArrayAdapter;
private ListView listView;
// ===========================================================
// onCreate
// ===========================================================
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.friends_list);
registerForContextMenu(getListView());
setButtonNewFriendClickListener();
}
public void generateFriendsList() {
FriendsService fs = new FriendsService(this);
friends = fs.getFriendsList();
listView = (ListView) findViewById(android.R.id.list);
friendsArrayAdapter = new FriendsArrayAdapter(
this, R.layout.friend_list_item, friends);
listView.setAdapter(friendsArrayAdapter);
}
@Override
public void onCreateContextMenu(ContextMenu menu, View v, ContextMenuInfo menuInfo) {
super.onCreateContextMenu(menu, v, menuInfo);
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.friends_context_menu, menu);
}
@Override
public boolean onContextItemSelected(MenuItem item) {
AdapterContextMenuInfo info = (AdapterContextMenuInfo) item.getMenuInfo();
FriendsService fs = new FriendsService(this);
Friend f = new Friend();
f = friends.get(info.position);
switch (item.getItemId()) {
case R.id.edit:
Intent i = new Intent(this, FriendEditActivity.class);
i.putExtra("userid", f.userId);
startActivity(i);
return true;
case R.id.delete:
fs.deleteFriend(f.userId);
generateFriendsList();
return true;
default:
return super.onContextItemSelected(item);
}
}
// ===========================================================
// onPause
// ===========================================================
protected void onPause() {
super.onPause();
finish();
}
// ===========================================================
// onResume
// ===========================================================
protected void onResume() {
super.onResume();
generateFriendsList();
}
// ===========================================================
// onStop
// ===========================================================
protected void onStop() {
super.onStop();
}
// ===========================================================
// onDestroy
// ===========================================================
@Override
protected void onDestroy() {
super.onDestroy();
}
// ===========================================================
// Activity methods
// ===========================================================
private void setButtonNewFriendClickListener() {
Button clickButton = (Button)findViewById(R.id.button_add_friend);
clickButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
Intent i = new Intent(v.getContext(), FriendNewActivity.class);
startActivity(i);
}
});
}
The AndroidManifest looks like this
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
android:versionCode="1"
android:versionName="1.0" package="com.package.mypackage">
<uses-permission android:name="android.permission.CAMERA" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<application android:icon="@drawable/icon" android:label="@string/app_name">
<activity android:name="com.package.mypackage.mypackage"
android:label="@string/app_name">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name=".FriendsListActivity"></activity>
<activity android:name=".FriendEditActivity"></activity>
<activity android:name=".FriendNewActivity"></activity>
<activity android:name=".TakePictureActivity"></activity>
<activity android:name=".FriendsService"></activity>
<activity android:name=".MyService"></activity>
</application>
<uses-sdk android:minSdkVersion="9" />
The MAIN activity looks like this:
package com.package.mypackage;
import java.util.ArrayList;
import com.package.domain.Domain;
import com.package.service.MyService;
import com.package.viewadapter.myImageAdapter;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.Window;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.AdapterView.OnItemLongClickListener;
import android.widget.Button;
import android.widget.Gallery;
import android.widget.Toast;
public class myActivity extends Activity {
// ===========================================================
// Fields
// ===========================================================
private MyImageAdapter myImageAdapter;
private ArrayList<Domain> domain = new ArrayList<Domain>();
// ===========================================================
// onCreate
// ===========================================================
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.main);
/* Set Buttons
to listen for any click event. */
setButtonFriendsClickListener();
setButtonCameraClickListener();
setButtonPreferencesClickListener();
}
// ===========================================================
// onStart
// ===========================================================
@Override
public void onStart() {
super.onStart();
/* Find
the gallery defined in
the main.xml */
Gallery g = (Gallery) findViewById(R.id.gallery);
/* Show a Toast message when image is clicked */
g.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View v, int position, long id) {
MyImageAdapter image_ID = new MyImageAdapter(myActivity.this, position, null);
if (image_ID.getItemId(position) == 0) {
Toast test_toast = Toast.makeText(myActivity.this, "This is
the New Image click", Toast.LENGTH_SHORT);
test_toast.show();
}
else {
Toast test_toast = Toast.makeText(myActivity.this, "
The clicked image has image number " + image_ID.getItemId(position) + " in
the imageadapter.", Toast.LENGTH_SHORT);
test_toast.show();
}
}
});
g.setOnItemLongClickListener(new OnItemLongClickListener() {
@Override
public boolean onItemLongClick(AdapterView<?> parent, View v, int position, long id) {
MyImageAdapter image_ID = new MyImageAdapter(myActivity.this, position, null);
Toast test_toast = Toast.makeText(myActivity.this, "
The long clicked image has image number " + image_ID.getItemId(position) + " in
the imageadapter.", Toast.LENGTH_SHORT);
test_toast.show();
return true;
}
});
}
// ===========================================================
// onPause
// ===========================================================
protected void onPause() {
super.onPause();
}
// ===========================================================
// onResume
// ===========================================================
protected void onResume() {
super.onResume();
generateMyGallery();
}
// ===========================================================
// onStop
// ===========================================================
protected void onStop() {
super.onStop();
}
// ===========================================================
// onDestroy
// Is also called when user changes from horizontal
//
to vertical orientation and
back
// ===========================================================
@Override
protected void onDestroy() {
super.onDestroy();
}
// ===========================================================
// Save and Restore UI states
// ===========================================================
@Override
protected void onRestoreInstanceState(Bundle savedInstanceState) {
super.onRestoreInstanceState(savedInstanceState);
}
protected void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
}
// ===========================================================
// Main Activity methods
// ===========================================================
public void generateMyGallery() {
MyService cs = new MyService(this);
domain = cs.getDomainList();
// Add
the new_image drawable
to the ArrayList
Domain d = new Domain();
d.photoLocation = "drawable";
d.photoName = "new_image";
d.extra1 = "no_text";
d.extra2 = "no_text";
domain.add(0, d);
myImageAdapter = new MyImageAdapter(this, R.layout.text_overlay_image_view, domain);
/* Find
the gallery defined in
the main.xml */
Gallery g = (Gallery) findViewById(R.id.gallery);
g.setSpacing(10);
/* Apply a new (custom) ImageAdapter
to it. */
g.setAdapter(myImageAdapter);
g.setSelection(1);
}
private void setButtonFriendsClickListener() {
Button clickButton = (Button)findViewById(R.id.button_friends_list);
clickButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
setContentView(R.layout.friends_list);
Intent myIntent = new Intent(v.getContext(), FriendsListActivity.class);
startActivity(myIntent);
}
});
}
private void setButtonCameraClickListener() {
Button clickButton = (Button)findViewById(R.id.button_take_picture);
clickButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
setContentView(R.layout.take_picture);
Intent myIntent = new Intent(v.getContext(), TakePictureActivity.class);
startActivity(myIntent);
}
});
}
private void setButtonPreferencesClickListener() {
Button clickButton = (Button)findViewById(R.id.button_preferences);
clickButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
Intent myIntent = new Intent(v.getContext(), MyPreferencesActivity.class);
startActivity(myIntent);
}
});
}
};
Anyone has an idea why
the App crashes. Any help is much appreciated.
I did find out that, when I finish()
the MAIN activity when I start
the FriendListActivity and restart
the MAIN activity when closing
the FriendListActivity, that
the crash does not occur. However, this basically restarts
the App and that is not
the intention.
Thanks all, I got
the problem solved. This is what I did.
. When moving all gallery related actions
to the onCreate,
the creash didn't happen anymore. But then after returning
to the MAIN activity,
the activity wasn't shown.
. I then moved all
the onCreate (except
the super),
the generateGallery, and
the onStart()
to the onResume. Now it works fine!
