基于Android的通讯录代码

以下是一个简单的基于 Android 平台的通讯录应用程序的代码示例：

MainActivity.java

import android.content.Intent;
import android.database.Cursor;
import android.os.Bundle;
import android.provider.ContactsContract;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;
import java.util.ArrayList;

public class MainActivity extends AppCompatActivity {

    private ListView listView;
    private ArrayList<Contact> contacts = new ArrayList<>();
    private ContactAdapter contactAdapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        listView = findViewById(R.id.listView);

        Cursor cursor = getContentResolver().query(ContactsContract.CommonDataKinds.Phone.CONTENT_URI, null, null, null, null);

        while (cursor.moveToNext()) {
            String name = cursor.getString(cursor.getColumnIndex(ContactsContract.CommonDataKinds.Phone.DISPLAY_NAME));
            String phoneNumber = cursor.getString(cursor.getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER));
            contacts.add(new Contact(name, phoneNumber));
        }

        cursor.close();

        contactAdapter = new ContactAdapter(this, contacts);
        listView.setAdapter(contactAdapter);

        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                Intent intent = new Intent(MainActivity.this, ContactActivity.class);
                intent.putExtra("name", contacts.get(position).getName());
                intent.putExtra("phoneNumber", contacts.get(position).getPhoneNumber());
                startActivity(intent);
            }
        });
    }
}

Contact.java

public class Contact {

    private String name;
    private String phoneNumber;

    public Contact(String name, String phoneNumber) {
        this.name = name;
        this.phoneNumber = phoneNumber;
    }

    public String getName() {
        return name;
    }

    public String getPhoneNumber() {
        return phoneNumber;
    }
}

ContactAdapter.java

import android.content.Context;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.TextView;
import java.util.ArrayList;

public class ContactAdapter extends ArrayAdapter<Contact> {

    private Context context;
    private ArrayList<Contact> contacts;

    public ContactAdapter(@NonNull Context context, ArrayList<Contact> contacts) {
        super(context, 0, contacts);
        this.context = context;
        this.contacts = contacts;
    }

    @NonNull
    @Override
    public View getView(int position, @Nullable View convertView, @NonNull ViewGroup parent) {
        View listItemView = convertView;
        if (listItemView == null) {
            listItemView = LayoutInflater.from(context).inflate(R.layout.contact_item, parent, false);
        }

        Contact currentContact = contacts.get(position);

        TextView nameTextView = listItemView.findViewById(R.id.nameTextView);
        nameTextView.setText(currentContact.getName());

        TextView phoneNumberTextView = listItemView.findViewById(R.id.phoneNumberTextView);
        phoneNumberTextView.setText(currentContact.getPhoneNumber());

        return listItemView;
    }
}

activity_main.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="16dp"
    android:paddingRight="16dp"
    android:paddingTop="16dp"
    tools:context=".MainActivity">

    <ListView
        android:id="@+id/listView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

</RelativeLayout>

contact_item.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="wrap_content"
    android:padding="16dp">

    <TextView
        android:id="@+id/nameTextView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="18sp"
        android:textStyle="bold" />

    <TextView
        android:id="@+id/phoneNumberTextView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@id/nameTextView"
        android:textSize="14sp" />

</RelativeLayout>

ContactActivity.java

import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

public class ContactActivity extends AppCompatActivity {

    private TextView nameTextView;
    private TextView phoneNumberTextView;
    private Button callButton;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_contact);

        nameTextView = findViewById(R.id.nameTextView);
        phoneNumberTextView = findViewById(R.id.phoneNumberTextView);
        callButton = findViewById(R.id.callButton);

        Intent intent = getIntent();
        String name = intent.getStringExtra("name");
        String phoneNumber = intent.getStringExtra("phoneNumber");

        nameTextView.setText(name);
        phoneNumberTextView.setText(phoneNumber);

        callButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                String phoneNumber = phoneNumberTextView.getText().toString();
                Intent intent = new Intent(Intent.ACTION_DIAL);
                intent.setData(Uri.parse("tel:" + phoneNumber));
                startActivity(intent);
            }
        });
    }
}

activity_contact.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="16dp"
    android:paddingRight="16dp"
    android:paddingTop="16dp"
    tools:context=".ContactActivity">

    <TextView
        android:id="@+id/nameTextView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="18sp"
        android:textStyle="bold" />

    <TextView
        android:id="@+id/phoneNumberTextView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@id/nameTextView"
        android:textSize="14sp" />

    <Button
        android:id="@+id/callButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@id/phoneNumberTextView"
        android:text="Call" />

</RelativeLayout>