I have built a test app that shows few records on a listview.
Now I want to click on an item and see the info on the debug of android studio.
I know I'm supposed to create an OnItemClickListener but I'm not sure where I'm supposed to place it.
I tried placing it on the mainactivity, the app works, but the click function is never called, so there is something wrong.
I looked around Google for some help, but I couldn't wrap my mind around it.
It should be a straightforward action (I have a list, I click an item) but I am not able to make it work.
This what I tried so far:
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;
import java.util.LinkedList;
import java.util.List;
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ListView listView = (ListView) findViewById(R.id.listViewDemo);
List list = new LinkedList();
list.add(new Contatto("Antonio","Rossi","1234567890"));
list.add(new Contatto("Pino","Bianchi","2345678901"));
list.add(new Contatto("Peppe","Verdi","3456789012"));
list.add(new Contatto("Leo","Rossi","4567890123"));
list.add(new Contatto("Mario","Blu","5678901234"));
list.add(new Contatto("Aldo","Da Vinci","6789012345"));
CustomAdapter adapter = new CustomAdapter(this, R.layout.rowcustom,list);
listView.setAdapter(adapter);
OnItemClickListener clickListener = new OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> adapter, View view,
int position, long id) {
Contatto c = (Contatto)adapter.getItem(position);
Log.d(c.getNome(),c.getTelefono());
}
};
listView.setOnItemClickListener(clickListener);
}
}
OnItemClickListener is not recognized, and getItem neither.
The autocorrect of android Studio proposes me to change to "AdapterView.OnItemClickListener", getItem has nooptions to be recognized.
I tried to add " implements OnItemClickListener" on the class declaration, but it doesn't work either (gives error, name is in red, no solutions are provided by the android studio).
At one point I was able to remove all errors, but the code still didn't work and I don't remember what I did, I was just fiddling.
You can put the OnClickListener in onCreate()
If you post your code, that would certainly help
There are a couple of things that are questionable about the code you posted.
You create OnItemClickListener but you don't have an import for AdapterView.OnItemClickListener. So are you sure you're using the right class?
Inside your onItemClick, you reference adapter, which is the local parameter of type AdapterView<?>, but AdapterView has no such method getItem(int). It can't be a reference to your CustomAdapter because that's not declared final.
Your use of Log.d(c.getNome(),c.getTelefono()); is wrong. The various log methods take a "tag" as the first parameter. It could be that you're not seeing the log messages because that's just wrong.
So, really, this shouldn't even compile. Please review your code and post the most recent, most correct, most compilable version you have. Including the code for you custom adapter and layout wouldn't hurt either.
Have you tried using your debugger to step through this code and seeing if a breakpoint at the click point gets hit?
I am trying to implement an activity which converts units. There are five fields which I want to be able to convert between on the fly. I can't simply use TextWatcher because when I change a field then that changes all the other fields and cause a circular call which crashes.
I looked at OnFocusChangeListener but that only works when the focus changes whereas I want the update to occur on the fly.
I then thought I could combine the two so I have my TextWatcher and inside that I put this
public void afterTextChanged(Editable s)
{
if (convert_kg.hasfocus())
{
if (convert_kg.getText().toString().matches("")) sums=0.0;
else sums=Double.parseDouble(convert_kg.getText().toString());
answer=(int)Math.round(sums*2.205);
convert_lbs.setText(String.format("%d", answer));
}
}
but I am getting an error of The method hasfocus() is undefined for the type EditText
These are my imports:
import android.os.Bundle;
import android.app.Activity;
import android.view.View;
import android.widget.TextView;
import android.widget.EditText;
import android.text.Editable;
import android.text.TextWatcher;
As far as I can tell from http://developer.android.com/reference/android/widget/EditText.html it should be supported? I'm sure this is simple but any ideas?
EDIT: In case anyone was wondering all the fields are EditText
convert_kg=(EditText)findViewById(R.id.convert_kg);
See the comments. isFocused() was the method I needed to use.
I'm having trouble following a guide on using SQLite in Android. I'm using a ListFragment instead of a ListActivity(as in the example), so I have the ListFragment implement LoaderManager.LoaderCallbacks<Cursor> instead. Then, in the fillData() method in the ListFragment:
private void fillData() {
// Fields from the database (projection)
// Must include the _id column for the adapter to work
String[] from = new String[] { NotesSQLiteHelper.COLUMN_TITLE };
// Fields on the UI to which we map
int[] to = new int[] { R.id.label };
getLoaderManager().initLoader(0, null, this); //error
adapter = new SimpleCursorAdapter(getApplicationContext(), R.layout.notes_row, null, from, to, 0);
setListAdapter(adapter);
}
I get the error:
The method initLoader(int, Bundle, LoaderManager.LoaderCallbacks<D>) in the type LoaderManager is not applicable for the arguments (int, null, NotesActivity.ArrayListFragment)
on the marked line even though this implements LoaderManager.LoaderCallbacks<Cursor>.
Thank you for any ideas.
You are not using the right implementations of CursorLoader and Loader.
Remove your old imports and use these ones:
import android.support.v4.app.LoaderManager;
import android.support.v4.content.CursorLoader;
import android.support.v4.content.Loader;
import android.support.v4.widget.CursorAdapter;
But I have the same Problem using SherlockActionBar:
As I have to extend SherlockListActivity there is NO method getSupportLoadManager().
Any ideas on this?
EDIT: follow this tutorial if you do not know how to use fragments. Create a new Class with extends SherlockFragment and move your display logic there. Make your old activity extend SherlockFragmentActivity and show the newly created SherlockFragment. This way I got it working. Thanks to #JakeWharton!
A few things to watch out for (from my recent experience battling with this):
If your minSDK is set to less than 11 (i.e. level 10 for Gingerbread) and you are using the Support Pack for backward compatibility, make sure you use
getSupportLoaderManager().initLoader(LOADER_ID, null, this);
You mentioned this when you said you are using ListFragment, but it bears repeating: Do not extend Activity, otherwise the support package will not work. Instead, extend the FragmentActivity class or the ListFragment class.
For your imports, make sure you are using the correct versions if your minSDK < 11:
android.support.v4.app.FragmentActivity;
android.support.v4.app.LoaderManager;
android.support.v4.content.Loader;
Hope this helps you... or at least someone else...
Casting the third argument solved the problem in my case:
from
getLoaderManager().initLoader(0, null, this);
to
getLoaderManager().initLoader(0, null, (android.app.LoaderManager.LoaderCallbacks<Cursor>) this);
Note:
minSdk was 8 and i was using support library v4.
(android.support.v4.app.LoaderManager.LoaderCallbacks<Cursor>) this)
did not work.
getSupportLoaderManager() or getSupportLoadManager()
did not work.
This code was inside activity not fragment
It's late but maybe help some one.
if you use loader maneger in fragment and you min api is below HONEYCOMB
you shuld use this imports
import android.support.v4.app.LoaderManager;
import android.support.v4.content.CursorLoader;
import android.support.v4.content.Loader;
import android.support.v4.widget.CursorAdapter;
import android.support.v4.app.Fragment;
and for initiate loader use this code
getActivity().getSupportLoaderManager().initLoader(/loader stuff*/);
hope this help some one.
Change your imports to
import android.support.v4.app.Fragment;
import android.support.v4.app.LoaderManager;
import android.support.v4.content.Loader;
and use
getSupportLoaderManager().initLoader(0, null, this);
This is what you have:
getLoaderManager().initLoader(0, null, this);
This is what you should have:
LoaderManager.getInstance(this).initLoader(0, null, this);
Reason for the first one not working:
/**
* #deprecated Use
* {#link LoaderManager#getInstance(LifecycleOwner) LoaderManager.getInstance(this)}.
*/
My error was beacause this:
//import android.app.ListFragment; Error when doesnt import from support.v4
import android.support.v4.app.ListFragment;
In my case I had to have my Activity extend ActionBarActivity from the android.support.v7.app package. I was then able to use
getSupportLoaderManager().initLoader(0, null, this);
I'm using ActionBarSherlock with my app and I as well was running into this issue and worked through all the steps discussed by others in this question. However I was continuing to have the same problem after trying all the suggested resolutions.
The method initLoader(int, Bundle, LoaderManager.LoaderCallbacks<D>) in the type LoaderManager is not applicable for the arguments (int, null, this)
The issue was I had fallen into expecting Eclipse to tell me when I was missing something and it was telling me that but not in the way I was used to. Typically Eclipse in other cases would tell me I'm missing the overrides to make something work but it's not directly saying that here. I finally picked up on the "LoaderManager.LoaderCallbacks" being the issue and realized I had no callbacks for it thus this error was actually a very valid error. Adding the basic overrides resolved my issue and allowed me to move forward.
// Creates a new loader after the initLoader () call
#Override
public Loader<Cursor> onCreateLoader(int id, Bundle args) {
// do work
return null;
}
#Override
public void onLoadFinished(Loader<Cursor> loader, Cursor data) {
adapter.swapCursor(data);
}
#Override
public void onLoaderReset(Loader<Cursor> loader) {
// data is not available anymore, delete reference
adapter.swapCursor(null);
}
I was having a similar issue where my AsyncTaskLoader was not returning my List, but my resolution was to change the call from .initLoader to .restartLoader.
So I actually never called .initLoader and just immediately called .restartLoader.
I had a onListItemClick listener in my fragment and every time backed out of the fragment and reloaded the onListItemClick and navigated through the app it kept crashing.
It might just be specific to my app but hopefully it helps others if they are having fragment backstack reload issues.
This was part of a file manager portion in my app so it is specific to clicking multiple onListItemClicks in the fragment you are loading.
I got around this by using a SherlockListFragment (or you could use ListFragment, I suppose), but have it contained within a Activity. I first created a generic FragmentHolderActivity class that looks like this:
FragmentHolderActivity.java
public class FragmentHolderActivity extends SherlockFragmentActivity {
public static final String FRAGMENT_LAYOUT_RESOURCE_ID = "fragment_layout_resource_id";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Integer fragmentLayoutResourceId = getIntent().getIntExtra(FRAGMENT_LAYOUT_RESOURCE_ID, Integer.MAX_VALUE);
Assert.assertNotSame(fragmentLayoutResourceId, Integer.MAX_VALUE);
setContentView(fragmentLayoutResourceId);
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case android.R.id.home:
finish();
return false;
default:
return super.onOptionsItemSelected(item);
}
}
}
Then you need to create an XML file for your fragment.
your_list_fragment.xml
<?xml version="1.0" encoding="utf-8"?>
<fragment
xmlns:android="http://schemas.android.com/apk/res/android"
android:name="com.example.YourListFragment"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/fragment" />
And here's the code you use to start the fragment:
Intent intent = new Intent();
intent.setClass(this, FragmentHolderActivity.class);
intent.putExtra(FragmentHolderActivity.FRAGMENT_LAYOUT_RESOURCE_ID, R.layout.your_list_fragment);
startActivity(intent);
You just tell the FragmentHolderActivity to use the your_list_fragment layout, which in turn loads the YourListFragment.java
You can then use: getSherlockActivity().getSupportLoaderManager().initLoader(...) in YourListFragment.java
Not sure if this is the correct approach, but it keeps all my logic in Fragments, which is nice.
Ran into the same problem. My minSdkVersion is 14, so cannot use android.support.v4 package.
I figured it by extending LoaderCallbacks, instead of LoaderManager.LoaderCallbacks and use these packages
import android.app.LoaderManager.LoaderCallbacks;
import android.content.CursorLoader;
import android.database.Cursor;
import android.widget.SimpleCursorAdapter;
If you have tried all the above methods and still facing the same error with the "this" parameter, then follow these steps :
Go to settings and enable imports on the fly option.(by default it'll
be enabled and you can do this by using Alt+Enter keys).
Cut the whole code of the activity which had implemented
LoaderCallback... and paste it in a text editor.
Then at last copy the whole code of that activity from the text editor
where you had pasted, without any import commands.( Only the code of
the class/activity).
You'll get lots of errors as you have imported nothing yet.
Just press Alt+Enter wherever you're getting the errors and it's
libraries will be imported automatically.
Note : Choose android.app... library for CursorLoaders.
Try these 2 lines it will work
android.support.v4.app.LoaderManager loaderManager = getSupportLoaderManager();
loaderManager.initLoader(LOADER_ID, null, this);
I am using minSDK 27 and had this same issue, I tried to cast like #Dexter suggest, but that gave an error saying cannot be cast to android.app.LoaderManager$LoaderCallbacks, so I then tried to use different import statements and this worked. I commented out the v4 versions and this is what I have now and the app is working:
//import android.support.v4.app.LoaderManager;
import android.app.LoaderManager;
import android.support.v4.app.NavUtils;
//import android.support.v4.content.CursorLoader;
import android.content.CursorLoader;
//import android.support.v4.content.Loader;
//import android.content.Loader;
Not quite sure when/how the v4 versions were imported.
0
After a long sacrifice i got this solution if you are using fragments then just use this code.
getActivity().getSupportLoaderManager().initLoader(1, null, YourActivity.this);
i hope this is helpful for you
I was trying to call initLoader() inside an activity. For me this worked
changing
getSupportLoaderManager().initLoader(LOADER_ID,null,this);
to
getLoaderManager().initLoader(LOADER_ID,null,this);
If you use API 28 or later, instead of getLoaderManager use:
getSupportLoaderManager().initLoader(id, null, this);
If you use API 29, instead of getLoaderManager use:
getSupportLoaderManager().initLoader(id, null, this);
I'm trying to get the text from one XML to another but it just crashes when its supposed to happen so any help will be welcomed!
Here is the code by the way
package com.android.test1;
import android.app.Activity;
import android.os.Bundle;
import android.widget.EditText;
import android.widget.TextView;
public class xmltwo extends Activity{
#Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.xmltwo);
TextView one = (TextView) findViewById(R.id.textView1);
EditText two = (EditText) findViewById(R.id.editText1);
one.setText(two.getText());
}
}
That's from the java file that opens the XML where the textView is.
My guess?
The logcat will be showing a NullPointerException for the line one.setText(two.getText()); because the layout file referenced by R.layout.xmltwo doesn't actually contain a TextView with an id of R.id.textView1 so the TextView called one is null.
Either that or that layout file doesn't contain an EditText with an id of R.id.editText1 which will make that null and cause an NPE when trying to call two.getText().
Just as an extra bit of information, if you want to get the text from an EditText you need to use getText().toString()
In this article Android: edit textview defined in xml one of the members has a similar issue. They theorize that possibly setContentView hasn't finished running yet and that may be the issue. However, you're saying that it is just completely crashing so I'm not sure if that could be the problem.
Could there be another part of your in your super class that could be hanging up? Could you use the getString() function instead perhaps?
I hope some of this might be helpful! I am interested in finding a solution so I intend to keep on reading to try and help!
try
one.setText(two.getText().toString().trim()+"");
hope this help..
I'm getting "cannot be resolved to a type" in my code. I'm looking for solution but all solutions are not working.
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
public class Vortex extends Activity {
private static final String LOG_TAG = Vortex.class.getSimpleName();
private VortexView _vortexView; //there is the problem
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
_vortexView = new VortexView(this);
setContentView(_vortexView);
}
}
The problem is with VortexView in this code. Eclipse tell me that VortexView cannot be resolved to a type.
Any solution?
Do you have VortexView class in your project, if so, ctrl+shift+O will resolve the issue. Otherwise add class/jar to classpaht and do ctrl+shift+O (organize imports).
VortexView is your custom view? If there exists VortexView.class
Probably, you have made either of the following two mistakes.
You have not extended a view named VortexView at all
You have extended it correctly, but you haven't made it available to the current package
When you are doing such things, it is better to define custom views inside the same package. Or even though you are defining it somewhere else, make it avilable where it is used.
import yourPackage.VortexView;
Hope this helps.