Initializing a Loader in an Activity

Question

I am currently trying to learn how to use Loaders and am having trouble starting a Loader in my activity.

import android.support.v4.app.LoaderManager;
import         


        

Answer 1

The third parameter for getLoaderManager().initLoader(0, null, this); should be a instance that implement interface LoaderManager.LoaderCallbacks So you should implement the interface first.

Answer 2

For AppCompatActivity use getSupportLoaderManager().initLoader(0,null,this); for initializing the loader.

Answer 3

As I can see you use supportV4 library. So to implement Loader you should do some things:

1. extend your activity from FragmentActivity class
2. Use getSupportLoaderManager method instead of getLoaderManager

here is sample code:

import android.os.Bundle;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.LoaderManager;
import android.support.v4.content.Loader;
import android.widget.Toast;

public class MyActivity extends FragmentActivity implements LoaderManager.LoaderCallbacks<Object> {
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    getSupportLoaderManager().initLoader(0, null, this);
}

@Override
public Loader<Object> onCreateLoader(int i, Bundle bundle){
    return null; // TODO
}

@Override
public void onLoadFinished(Loader loader, Object o) {
    Toast.makeText(this, "onLoadFinished", Toast.LENGTH_SHORT).show();
}

@Override
public void onLoaderReset(Loader loader)    {
    Toast.makeText(this, "onLoaderReset", Toast.LENGTH_SHORT).show();
}
}

Answer 4

When using loaders with fragments use:

getLoaderManager().initLoader(0,null,this);

And when using loaders with Activity use:

getSupportLoaderManager().initLoader(0,null,this);