I'm new in android programming and in my first app i need to understand how to easily populate a ListView getting data from SQlite. For best understanding, my app has 4 Tabs in the main activity (Tab Layout), switching the tabs i need to load the data previously saved in the database and populate the ListView (using Support Library). I've found some examples using CursorAdapter, like this one https://guides.codepath.com/android/Populating-a-ListView-with-a-CursorAdapter but i don't know how to make work the ViewPagerAdapter with the CursorAdapter.
ViewPagerAdapter
import android.support.v4.app.Fragment; import android.support.v4.app.FragmentManager; import android.support.v4.app.FragmentStatePagerAdapter; import android.content.Context; public class ViewPagerAdapter extends FragmentStatePagerAdapter { CharSequence Titles[]; // This will Store the Titles of the Tabs which are Going to be passed when ViewPagerAdapter is created int NumbOfTabs; // Store the number of tabs, this will also be passed when the ViewPagerAdapter is created private Context context; // Build a Constructor and assign the passed Values to appropriate values in the class public ViewPagerAdapter(FragmentManager fm,CharSequence mTitles[], int mNumbOfTabsumb) { super(fm); this.Titles = mTitles; this.NumbOfTabs = mNumbOfTabsumb; } //This method return the fragment for the every position in the View Pager @Override public Fragment getItem(int position) { if(position == 0) // if the position is 0 we are returning the First tab { Tab1 tab1 = new Tab1(); return tab1; } else if(position == 1){ Tab2 tab2 = new Tab2(); return tab2; } else if(position == 2) { Tab3 tab3 = new Tab3(); //THIS IS THE TAB TO POPULATE return tab3; //HOW TO RETURN TAB3 (CURSOR ADAPTER)? } else if(position == 3) { Tab4 tab4 = new Tab4(); return tab4; } else { Tab1 tab1 = new Tab1(); return tab1; } } // This method return the titles for the Tabs in the Tab Strip @Override public CharSequence getPageTitle(int position) { return Titles[position]; } // This method return the Number of tabs for the tabs Strip @Override public int getCount() { return NumbOfTabs; } } Tab3.java (i've modified this Tab java according to the example linked before)
import android.content.Context; import android.database.Cursor; import android.database.sqlite.SQLiteDatabase; import android.support.v4.widget.CursorAdapter; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.ListView; import android.widget.TextView; import com.tyr.R; import com.myapp.library.DatabaseNumbersHandler; public class Tab3 extends CursorAdapter { public Tab3(Context context, Cursor cursor, int flags) { super(context, cursor, 0); } // The newView method is used to inflate a new view and return it, // you don't bind any data to the view at this point. @Override public View newView(Context context, Cursor cursor, ViewGroup parent) { return LayoutInflater.from(context).inflate(R.layout.tab_3_list, parent, false); } // The bindView method is used to bind all data to a given view // such as setting the text on a TextView. @Override public void bindView(View view, Context context, Cursor cursor) { // Find fields to populate in inflated template TextView numTitle = (TextView) view.findViewById(R.id.num_title); // Extract properties from cursor String body = cursor.getString(cursor.getColumnIndexOrThrow("title")); // Populate fields with extracted properties numTitle.setText(body); // TodoDatabaseHandler is a SQLiteOpenHelper class connecting to SQLite DatabaseNumbersHandler handler = new DatabaseNumbersHandler(context); // Get access to the underlying writeable database SQLiteDatabase db = handler.getWritableDatabase(); // Query for items from the database and get a cursor back Cursor todoCursor = db.rawQuery("SELECT title FROM NUMBERS", null); // Find ListView to populate ListView lvItems = (ListView) view.findViewById(R.id.tab_3_list); // Setup cursor adapter using cursor from last step Tab3 todoAdapter = new Tab3(context, todoCursor, 0); // Attach cursor adapter to the ListView lvItems.setAdapter(todoAdapter); } } tab_3_list.xml
<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin" android:paddingRight="@dimen/activity_horizontal_margin" android:paddingTop="@dimen/activity_vertical_margin" android:paddingBottom="@dimen/activity_vertical_margin" tools:context="com.tyr.MainSettings"> <ListView android:id="@+id/tab_3_list" android:layout_width="wrap_content" android:layout_height="wrap_content" > </ListView> </RelativeLayout> tab_3.xml
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="horizontal" > <TextView android:id="@+id/num_title" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginLeft="10dp" android:text="3" android:textAppearance="?android:attr/textAppearanceMedium" /> </LinearLayout> Tab4.java (the other Tabs are like this one, and show a simple Text)
public class Tab4 extends Fragment{ @Override public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) { View v = inflater.inflate(R.layout.tab_4,container,false); return v; } } tab_4.xml
<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent"> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:textAppearance="?android:attr/textAppearanceMedium" android:text="You Are In Tab 4" android:id="@+id/textView" android:layout_centerVertical="true" android:layout_centerHorizontal="true" /> </RelativeLayout> How can i return correctly the tab3 populating the ListView?
