读取系统联系人

class MainActivity : AppCompatActivity() {

    private val contactsList = ArrayList<String>()
    private lateinit var adapter: ArrayAdapter<String>

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        adapter = ArrayAdapter(this, android.R.layout.simple_list_item_1, contactsList)
        contactsView.adapter = adapter
        ……
        readContacts()
    }
    ……
    private fun readContacts() {
        // 查询联系人数据
        contentResolver.query(ContactsContract.CommonDataKinds.Phone.CONTENT_URI, null, null, null, null)?.apply {
            while (moveToNext()) {
                // 获取联系人姓名
                val displayName = getString(getColumnIndex(ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME))
                // 获取联系人手机号
                val number = getString(getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER))
                contactsList.add("$displayName
$number")
            }
            adapter.notifyDataSetChanged()
            close()
        }
    }
}