Here is a simple example to list contacts in android using the Content Resolver.
Note :
You need to have two things before accessing contacts.
1. Contacts Permission in the Android Manifest
<uses-permission android:name="android.permission.READ_CONTACTS" /> |
2. Ask Runtime permission from the user
Contacts Android – Content Resolver
Code
Here is our MainActivity that lists the contacts.
MainActivity.java
package contacts.coderzheaven.com.samplesproject;import android.content.ContentResolver;import android.content.Context;import android.content.pm.PackageManager;import android.database.Cursor;import android.os.Build;import android.os.Bundle;import android.provider.ContactsContract;import android.support.annotation.NonNull;import android.support.v4.app.ActivityCompat;import android.support.v7.app.AppCompatActivity;import android.widget.ListView;import android.widget.Toast;import static contacts.coderzheaven.com.samplesproject.ContactListAdapter.CONTACT_PROJECTION;public class MainActivity extends AppCompatActivity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); checkContactPermissions(); } private void setContacts() { ContentResolver content = getContentResolver(); Cursor cursor = content.query(ContactsContract.Contacts.CONTENT_URI, CONTACT_PROJECTION, null, null, null); ContactListAdapter adapter = new ContactListAdapter( this, cursor); ListView listView = findViewById(R.id.listView); listView.setAdapter(adapter); } private void checkContactPermissions() { if (Build.VERSION.SDK_INT >= 23) { String[] PERMISSIONS = {android.Manifest.permission.READ_CONTACTS}; if (!hasPermissions(this, PERMISSIONS)) { ActivityCompat.requestPermissions(this, PERMISSIONS, 100); } else { setContacts(); } } else { setContacts(); } } private static boolean hasPermissions(Context context, String... permissions) { if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M && context != null && permissions != null) { for (String permission : permissions) { if (ActivityCompat.checkSelfPermission(context, permission) != PackageManager.PERMISSION_GRANTED) { return false; } } } return true; } @Override public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) { super.onRequestPermissionsResult(requestCode, permissions, grantResults); switch (requestCode) { case 100: { if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) { setContacts(); } else { Toast.makeText(this, "The app was not allowed to read your contact", Toast.LENGTH_LONG).show(); } } } }} |
Adapter Class
Below is the adapter class for the Listview in the UI.
We name it “ContactListAdapter.java”.
package contacts.coderzheaven.com.samplesproject;import android.content.ContentResolver;import android.content.Context;import android.database.Cursor;import android.net.Uri;import android.provider.ContactsContract;import android.support.v4.widget.CursorAdapter;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.FilterQueryProvider;import android.widget.Filterable;import android.widget.TextView;class ContactListAdapter extends CursorAdapter implements Filterable { public ContactListAdapter(Context context, Cursor c) { super(context, c); mContent = context.getContentResolver(); } @Override public View newView(Context context, Cursor cursor, ViewGroup parent) { final LayoutInflater inflater = LayoutInflater.from(context); final TextView view = (TextView) inflater.inflate( android.R.layout.simple_dropdown_item_1line, parent, false); view.setText(cursor.getString(COLUMN_DISPLAY_NAME)); return view; } @Override public void bindView(View view, Context context, Cursor cursor) { ((TextView) view).setText(cursor.getString(COLUMN_DISPLAY_NAME)); } @Override public String convertToString(Cursor cursor) { return cursor.getString(COLUMN_DISPLAY_NAME); } @Override public Cursor runQueryOnBackgroundThread(CharSequence constraint) { FilterQueryProvider filter = getFilterQueryProvider(); if (filter != null) { return filter.runQuery(constraint); } Uri uri = Uri.withAppendedPath(ContactsContract.Contacts.CONTENT_FILTER_URI, Uri.encode(constraint.toString())); return mContent.query(uri, CONTACT_PROJECTION, null, null, null); } private ContentResolver mContent; public static final String[] CONTACT_PROJECTION = new String[]{ ContactsContract.Contacts._ID, ContactsContract.Contacts.DISPLAY_NAME}; private static final int COLUMN_DISPLAY_NAME = 1;} |
Layout
Finally the layout. The layout is simple, it just contains a Listview.
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="wrap_content" android:orientation="vertical" android:padding="20dp"> <ListView android:id="@+id/listView" android:layout_width="match_parent" android:layout_height="wrap_content" /></LinearLayout> |
Download Source Code
You can download the full android studio source code from here.