フラグメントを介して Caldroid カレンダーを作成しました。
これは、カレンダーを作成する CalendarFragment.java ファイルです。
package com.petar.android.simplenote;
import android.graphics.drawable.ColorDrawable;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentTransaction;
import android.support.v4.content.ContextCompat;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import com.petar.android.simplenote.beans.Drop;
import com.roomorama.caldroid.CaldroidFragment;
import java.util.Calendar;
import java.util.Date;
import io.realm.Realm;
import io.realm.RealmResults;
/**
* A simple {@link Fragment} subclass.
*/
public class CalendarFragment extends Fragment {
CaldroidFragment caldroidFragment;
public CalendarFragment() {
// Required empty public constructor
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View rootView = inflater.inflate(R.layout.calendar_fragment, container, false);
caldroidFragment = new CaldroidFragment();
Bundle args = new Bundle();
Calendar cal = Calendar.getInstance();
args.putInt("month", cal.get(Calendar.MONTH) + 1);
args.putInt("year", cal.get(Calendar.YEAR));
caldroidFragment.setArguments(args);
//calling this metod will cause to pull data from Realm Data Base and set backgroud for saved dates in database
postaviPozadinskuBojuNota();
FragmentTransaction t = getChildFragmentManager().beginTransaction();
t.replace(R.id.calendar_container, caldroidFragment);
t.commit();
caldroidFragment.refreshView();
return rootView;
}
//pulling data from database and setting backgroud for Date
public void postaviPozadinskuBojuNota() {
Realm realm = null;
try {
Date date;
realm = Realm.getDefaultInstance();
RealmResults<Drop> results = realm.where(Drop.class).equalTo("completed", false).equalTo("deleted", false).findAll(); //posto smo u thredu nemoramo findAllAsyinc
for (Drop current : results) {
if (current.getColorPickerRoudIcon() == R.drawable.ic_drop_black) {
long item_time = current.getWhen();//getting time from Realm Data Base
date = new Date(item_time);
caldroidFragment.setBackgroundDrawableForDate(new ColorDrawable(ContextCompat.getColor(getActivity(), R.color.calendarBlack)), date);
}
if (current.getColorPickerRoudIcon() == R.drawable.ic_drop_red) {
long item_time = current.getWhen();//getting time from Realm Data Base
date = new Date(item_time);
caldroidFragment.setBackgroundDrawableForDate(new ColorDrawable(ContextCompat.getColor(getActivity(), R.color.calendarRed)), date);
}
if (current.getColorPickerRoudIcon() == R.drawable.ic_drop) {
long item_time = current.getWhen();//getting time from Realm Data Base
date = new Date(item_time);
caldroidFragment.setBackgroundDrawableForDate(new ColorDrawable(ContextCompat.getColor(getActivity(), R.color.calendarBlue)), date);
}
if (current.getColorPickerRoudIcon() == R.drawable.ic_drop_yellow) {
long item_time = current.getWhen();//getting time from Realm Data Base
date = new Date(item_time);
caldroidFragment.setBackgroundDrawableForDate(new ColorDrawable(ContextCompat.getColor(getActivity(), R.color.calendarYellow)), date);
}
if (current.getColorPickerRoudIcon() == R.drawable.ic_drop_green) {
long item_time = current.getWhen();//getting time from Realm Data Base
date = new Date(item_time);
caldroidFragment.setBackgroundDrawableForDate(new ColorDrawable(ContextCompat.getColor(getActivity(), R.color.calendarGreen)), date);
}
if (current.getColorPickerRoudIcon() == R.drawable.ic_drop_white) {
long item_time = current.getWhen();//getting time from Realm Data Base
date = new Date(item_time);
caldroidFragment.setBackgroundDrawableForDate(new ColorDrawable(ContextCompat.getColor(getActivity(), R.color.calendarWhite)), date);
}
}
} finally {
if (realm != null) {
realm.close();
}
}
}
//this method is called from activity
public void testUpdateEveryting() {
postaviPozadinskuBojuNota();
caldroidFragment.refreshView();
}
}
Activity から CalendarFragment.java の最後のメソッドを呼び出したい これは私が呼び出すメソッドです
//this method is called from activity
public void testUpdateEveryting() {
postaviPozadinskuBojuNota();
caldroidFragment.refreshView();
}
そして、次のようなボタンをクリックすると、Activity からそのメソッドを呼び出します。
CalendarFragment calendarFragment = new CalendarFragment();
calendarFragment.testUpdateEveryting();
私が達成したいのは、呼び出して日付の背景を更新することです
postaviPozadinskuBojuNota();
ボタンを押すと、次のエラーメッセージが表示されます。
FATAL EXCEPTION: main Process: com.petar.android.simplenote, PID: 21735
java.lang.NullPointerException: Attempt to invoke virtual method 'int android.content.Context.getColor(int)' on a null object reference
at android.support.v4.content.ContextCompatApi23.getColor(ContextCompatApi23.java:31)
at android.support.v4.content.ContextCompat.getColor(ContextCompat.java:404)
at com.petar.android.simplenote.CalendarFragment.postaviPozadinskuBojuNota(CalendarFragment.java:79)
at com.petar.android.simplenote.CalendarFragment.testUpdateEveryting(CalendarFragment.java:106)
at com.petar.android.simplenote.ActivityMain.onOptionsItemSelected(ActivityMain.java:351)
at android.app.Activity.onMenuItemSelected(Activity.java:3204)
ボタンを押して CaldroidFragment のメソッドを呼び出すと、すべてがクラッシュする
//this method is called from activity
public void testUpdateEveryting() {
postaviPozadinskuBojuNota();
caldroidFragment.refreshView();
}
次に、このメソッドが呼び出されます。
postaviPozadinskuBojuNota();
そして、すべてがこの行でクラッシュします
caldroidFragment.setBackgroundDrawableForDate(new ColorDrawable (ContextCompat.getColor(getActivity(), R.color.calendarGreen)), date);
エラーあり:
java.lang.NullPointerException: Attempt to invoke virtual method 'int android.content.Context.getColor(int)' on a null object reference
at android.support.v4.content.ContextCompatApi23.getColor(ContextCompatApi23.java:31)
at android.support.v4.content.ContextCompat.getColor(ContextCompat.java:404)