Different behaviour of getApplicationContext()
I use TinyDB to pass ArrayList from one Activity to another. TinyDB has constructor like this:
public class TinyDB {
public TinyDB(Context appContext) {
preferences = PreferenceManager.getDefaultSharedPreferences(appContext);
}
}
When I initialize TinyDB inside method, everything works fine:
@Override
public boolean onOptionsItemSelected(MenuItem item) {
TinyDB tinydb = new TinyDB(getApplicationContext());
}
But when I put this raw outside any method,
TinyDB tinydb = new TinyDB(getApplicationContext());
@Override
public boolean onOptionsItemSelected(MenuItem item) {
}
it appears java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.Context android.content.Context.getApplicationContext()' on a null object reference
Could someone explain me what the difference between these two ways of initializing TinyDB? Any references also will be appreciated.
methods context
asked yesterday
Dzianis
316
add a comment |
I use TinyDB to pass ArrayList from one Activity to another. TinyDB has constructor like this:
public class TinyDB {
public TinyDB(Context appContext) {
preferences = PreferenceManager.getDefaultSharedPreferences(appContext);
}
}
When I initialize TinyDB inside method, everything works fine:
@Override
public boolean onOptionsItemSelected(MenuItem item) {
TinyDB tinydb = new TinyDB(getApplicationContext());
}
But when I put this raw outside any method,
TinyDB tinydb = new TinyDB(getApplicationContext());
@Override
public boolean onOptionsItemSelected(MenuItem item) {
}
it appears java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.Context android.content.Context.getApplicationContext()' on a null object reference
Could someone explain me what the difference between these two ways of initializing TinyDB? Any references also will be appreciated.
methods context
asked yesterday
Dzianis
316
add a comment |
I use TinyDB to pass ArrayList from one Activity to another. TinyDB has constructor like this:
public class TinyDB {
public TinyDB(Context appContext) {
preferences = PreferenceManager.getDefaultSharedPreferences(appContext);
}
}
When I initialize TinyDB inside method, everything works fine:
@Override
public boolean onOptionsItemSelected(MenuItem item) {
TinyDB tinydb = new TinyDB(getApplicationContext());
}
But when I put this raw outside any method,
TinyDB tinydb = new TinyDB(getApplicationContext());
@Override
public boolean onOptionsItemSelected(MenuItem item) {
}
it appears java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.Context android.content.Context.getApplicationContext()' on a null object reference
Could someone explain me what the difference between these two ways of initializing TinyDB? Any references also will be appreciated.
methods context
asked yesterday
Dzianis
316
I use TinyDB to pass ArrayList from one Activity to another. TinyDB has constructor like this:
public class TinyDB {
public TinyDB(Context appContext) {
preferences = PreferenceManager.getDefaultSharedPreferences(appContext);
}
}
When I initialize TinyDB inside method, everything works fine:
@Override
public boolean onOptionsItemSelected(MenuItem item) {
TinyDB tinydb = new TinyDB(getApplicationContext());
}
But when I put this raw outside any method,
TinyDB tinydb = new TinyDB(getApplicationContext());
@Override
public boolean onOptionsItemSelected(MenuItem item) {
}
it appears java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.Context android.content.Context.getApplicationContext()' on a null object reference
Could someone explain me what the difference between these two ways of initializing TinyDB? Any references also will be appreciated.
methods context
methods context
asked yesterday
Dzianis
316
asked yesterday
Dzianis
316
asked yesterday
Dzianis
316
asked yesterday
Dzianis
316
asked yesterday
Dzianis
316
316
add a comment |
add a comment |
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