Follow these steps to query contacts.

1. Double-click the project in Visual Studio and navigate to project Properties.
2. Select the Android Application panel in the Project Options dialog in the Properties navigator in VS.
3. Click the Add Android Manifest button.
4. Under Required permissions set the READ_CONTACTS permission and press OK.
5. Add a file named ContactItemView.axml under the Resources/layout folder containing the following XML.

<?xml version="1.0" encoding="UTF-8" ?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
 android:padding="15dip"/>

In a ListActivity subclass, add the following code to the OnCreate method:

var uri = ContactsContract.Contacts.ContentUri;

string[] projection = { ContactsContract.Contacts.InterfaceConsts.Id,
       ContactsContract.Contacts.InterfaceConsts.DisplayName };

var cursor = ContentResolver.Query(uri, projection, null, null, null);

var contactList = new List<string> ();

if (cursor.MoveToFirst ()) {
       do {
              contactList.Add (cursor.GetString (
                      cursor.GetColumnIndex (projection [1])));
       }  while (cursor.MoveToNext());
}

ListAdapter = new ArrayAdapter<string> (this,
       Resource.Layout.ContactItemView, contactList);

ContactsContract.Contacts is the data contract that is used to interface with contact data. The code queries contacts at the Uri defined by ContactsContract.Contacts.ContentUri, returning the columns selected from ContactsContract.Contacts.InterfaceConsts. It adds the results to List<string> instance that is used to bind to the user interface through an ArrayAdapter.