Android studio中写一个用contentResolver()方法实现读取通讯录并功能实现发短信和打电话的代码

以下是一个使用contentResolver()方法实现读取通讯录并实现发短信和打电话功能的示例代码：

public class MainActivity extends AppCompatActivity {

    private static final int READ_CONTACTS_PERMISSIONS_REQUEST = 1;
    private static final int REQUEST_SEND_SMS = 2;
    private static final int REQUEST_CALL_PHONE = 3;

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

        if (ContextCompat.checkSelfPermission(this, Manifest.permission.READ_CONTACTS)
                != PackageManager.PERMISSION_GRANTED) {
            ActivityCompat.requestPermissions(this,
                    new String[]{Manifest.permission.READ_CONTACTS},
                    READ_CONTACTS_PERMISSIONS_REQUEST);
        } else {
            readContacts();
        }
    }

    private void readContacts() {
        String[] projection = new String[]{ContactsContract.Contacts.DISPLAY_NAME,
                ContactsContract.CommonDataKinds.Phone.NUMBER};
        String sortOrder = ContactsContract.Contacts.DISPLAY_NAME + " ASC";

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

        if (cursor != null && cursor.getCount() > 0) {
            while (cursor.moveToNext()) {
                String name = cursor.getString(0);
                String phone = cursor.getString(1);
                Log.d("Contacts", name + " - " + phone);
            }
            cursor.close();
        }
    }

    public void sendMessage(String phoneNumber, String message) {
        if (ContextCompat.checkSelfPermission(this, Manifest.permission.SEND_SMS)
                != PackageManager.PERMISSION_GRANTED) {
            ActivityCompat.requestPermissions(this,
                    new String[]{Manifest.permission.SEND_SMS},
                    REQUEST_SEND_SMS);
        } else {
            SmsManager smsManager = SmsManager.getDefault();
            smsManager.sendTextMessage(phoneNumber, null, message, null, null);
            Toast.makeText(this, "Message sent successfully", Toast.LENGTH_SHORT).show();
        }
    }

    public void callPhoneNumber(String phoneNumber) {
        if (ContextCompat.checkSelfPermission(this, Manifest.permission.CALL_PHONE)
                != PackageManager.PERMISSION_GRANTED) {
            ActivityCompat.requestPermissions(this,
                    new String[]{Manifest.permission.CALL_PHONE},
                    REQUEST_CALL_PHONE);
        } else {
            Intent callIntent = new Intent(Intent.ACTION_CALL, Uri.parse("tel:" + phoneNumber));
            startActivity(callIntent);
        }
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        if (requestCode == READ_CONTACTS_PERMISSIONS_REQUEST) {
            if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                readContacts();
            }
        } else if (requestCode == REQUEST_SEND_SMS) {
            if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                // Permission granted, send SMS
                sendMessage("1234567890", "Hello, world!");
            }
        } else if (requestCode == REQUEST_CALL_PHONE) {
            if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                // Permission granted, call phone
                callPhoneNumber("1234567890");
            }
        }
    }
}

在这个示例代码中，`readContacts()`方法使用`contentResolver()`方法读取通讯录，并将结果输出到Logcat中。`sendMessage()`方法使用`SmsManager`类发送短信。`callPhoneNumber()`方法使用`Intent.ACTION_CALL`和`Uri.parse()`来拨打电话。在`onRequestPermissionsResult()`方法中，我们检查用户是否授予了所需的权限，并在授予权限后执行相应的操作。请注意，这些权限请求的响应代码已在示例代码中定义。