的SmsObserver类是ContentObserver该寄存器本身上的content://sms/
Uri反对接收者的地址和消息主体中的SMS表并检查改变检索对于呼出SMS消息所分配的线程ID。该类提供了您的发送类需要实现的接口，以便在确定线程ID时接收它，因为这将异步发生。

public class SmsObserver extends ContentObserver {
    private static final Handler handler = new Handler();
    private static final Uri uri = Uri.parse("content://sms/");

    private final Context context;
    private final ContentResolver resolver;
    private final String address;
    private final String body;

    public interface OnSmsSentListener {
        public void onSmsSent(int threadId);
    }

    public SmsObserver(Context context, String address, String body) {
        super(handler);

        if (context instanceof OnSmsSentListener) {
            this.context = context;
            this.resolver = context.getContentResolver();
            this.address = address;
            this.body = body;
        }
        else {
            throw new IllegalArgumentException(
                "Context must implement OnSmsSentListener interface");
        }
    }

    public void start() {
        if (resolver != null) {
            resolver.registerContentObserver(uri, true, this);
        }
        else {
            throw new IllegalStateException(
                "Current SmsObserver instance is invalid");
        }
    }

    @Override
    public void onChange(boolean selfChange, Uri uri) {
        Cursor cursor = null;

        try {
            cursor = resolver.query(uri, null, null, null, null);

            if (cursor != null && cursor.moveToFirst()) {
                final int type = cursor.getInt(
                    cursor.getColumnIndex(Telephony.Sms.TYPE));

                if(type == Telephony.Sms.Sent.MESSAGE_TYPE_SENT) {
                    final String address = cursor.getString(
                        cursor.getColumnIndex(Telephony.Sms.ADDRESS));
                    final String body = cursor.getString(
                        cursor.getColumnIndex(Telephony.Sms.BODY));
                    final int threadId = cursor.getInt(
                        cursor.getColumnIndex(Telephony.Sms.THREAD_ID));

                    if (PhoneNumberUtils.compare(address, this.address) &&
                        body.equals(this.body)) {

                        ((OnSmsSentListener) context).onSmsSent(threadId);
                        resolver.unregisterContentObserver(this);
                    }
                }
            }
        }
        finally {
            if (cursor != null) {
                cursor.close();
            }
        }
    }
}

在发送消息之前，需要启动此实例，并将线程ID传递到发送类的接口方法实现中。例如，如果您是Activity通过点击发送来自的Button：

public class MainActivity extends Activity
    implements SmsObserver.OnSmsSentListener {
    ...

    public void onClick(View v) {
        String address = "+1 234 567 8900";
        String body = "HI Greg! ";

        new SmsObserver(this, address, body).start();

        SmsManager smsManager = SmsManager.getDefault();
        smsManager.sendTextMessage(address, null, body, null, null);
    }

    @Override
    public void onSmsSent(int threadId) {
        // Here's the thread ID.
    }
}

请注意，您还将需要获得READ_SMS许可。

从棒棒糖开始可能的替代方法。所发送的消息的URI将作为被附接String额外的Intent从PendingIntent通过如在第四个参数sendTextMessage()的方法。额外的将具有key
"uri"，并且可以将其解析为Uri，然后可以在查询中使用它ContentResolver来检索线程ID，如上所示。

例如，如果使用a BroadcastReceiver作为结果，则sendTextMessage()调用将如下所示：

Intent sentIntent = ...
PendingIntent sentPi = PendingIntent.getBroadcast(context, 0, sentIntent, 0);

SmsManager smsManager = SmsManager.getDefault();
smsManager.sendTextMessage(address, null, body, sentPi, null);

并在Receiver中检索额外的内容是这样的：

public class SmsResultReceiver extends BroadcastReceiver {
    @Override
    public void onReceive(Context context, Intent intent) {
        ...

        String uriString = data.getStringExtra("uri");
        Uri uri = Uri.parse(uriString);

        // Query as shown above in the ContentObserver
        ...
    }
}