通过Intent发送短信并了解短信是否已发送

我尝试使用以下代码通过 Intent 发送短信：

Intent intent = new Intent(Intent.ACTION_VIEW);
intent.setData(Uri.parse("smsto:" + phoneNumber));
intent.putExtra("address", phoneNumber);
intent.putExtra("sms_body", messageBody);
intent.putExtra("exit_on_sent", true);
startActivityForResult(intent, CODE);

然后，我想知道短信是否已发送，我使用以下代码：

public void onActivityResult(int requestCode, int resultCode, Intent intent) {

    switch (requestCode) {

        case CODE:
        if (resultCode == Activity.RESULT_OK)
        {
            //Then do...
        }
        elseif(resultCode == Activity.RESULT_CANCELED)
        {
            // Do...
        }
        break;    
    }
}

问题是结果始终为 0 (Activity.RESULT_CANCELED)，即使 SMS 已发送。我如何知道短信是否已发送？我想使用手机的短信默认应用程序，而不是创建发送短信的界面。

在下面的示例中，我们使用ContentObserver监控 SMS 提供商的更新。该观察者在 SMS Intent 触发之前创建并启动，并根据目标地址检查提供程序的更改。创建观察者的 Activity 必须实现SmsSendObserver.SmsSendListener接收回调的接口。

观察者的构造函数包括timeout参数（以毫秒为单位），如果在合理的时间后未发送消息，则允许观察者正确取消注册。这可以设置为NO_TIMEOUT如果需要的话。然而，正如所写的，该类旨在“一次性”使用，并且它将在回调时取消注册并取消成员。这stop()如果没有回调发生，可以使用方法来清理。无论哪种情况，该实例都不再可用，并且对它的任何引用都应设置为 null。

活动示例：

public class MainActivity extends Activity
    implements SmsSendObserver.SmsSendListener {
    ...

    private void sendMessage(String phoneNumber, String messageBody) {
        // This example has a timeout set to 15 seconds
        new SmsSendObserver(this, phoneNumber, 15000).start();

        Intent intent = new Intent(Intent.ACTION_VIEW);
        intent.setData(Uri.parse("smsto:" + phoneNumber));
        intent.putExtra("address", phoneNumber);
        intent.putExtra("sms_body", messageBody);
        intent.putExtra("exit_on_sent", true);
        startActivity(intent);
    }

    public void onSmsSendEvent(boolean sent) {
        Toast.makeText(this, sent ? "Message was sent" : "Timed out",
                       Toast.LENGTH_SHORT).show();
    }
}

The SmsSendObserver class:

public class SmsSendObserver extends ContentObserver {
    public static final int NO_TIMEOUT = -1;

    private static final Handler handler = new Handler();
    private static final Uri uri = Uri.parse("content://sms/"); 

    private static final String COLUMN_ADDRESS = "address";
    private static final String COLUMN_TYPE = "type";
    private static final String[] PROJECTION = { COLUMN_ADDRESS, COLUMN_TYPE };
    private static final int MESSAGE_TYPE_SENT = 2;

    private Context context = null;
    private ContentResolver resolver = null;

    private String phoneNumber = null;
    private long timeout = NO_TIMEOUT;
    private boolean wasSent = false;
    private boolean timedOut = false;

    public SmsSendObserver(Context context, String phoneNumber, long timeout) {
        super(handler);

        if (context instanceof SmsSendListener) {       
            this.context = context;
            this.resolver = context.getContentResolver();
            this.phoneNumber = phoneNumber;
            this.timeout = timeout;
        }
        else {
            throw new IllegalArgumentException(
                "Context must implement SmsSendListener interface");
        }
    }

    private Runnable runOut = new Runnable() {
        @Override
        public void run() {
            if (!wasSent) {
                timedOut = true;
                callBack();
            }
        }
    };

    public void start() {
        if (resolver != null) {
            resolver.registerContentObserver(uri, true, this);

            if (timeout > NO_TIMEOUT) {
                handler.postDelayed(runOut, timeout);
            }
        }
        else {
            throw new IllegalStateException(
                "Current SmsSendObserver instance is invalid");
        }
    }

    public void stop() {
        if (resolver != null) {
            resolver.unregisterContentObserver(this);

            resolver = null;
            context = null;
        }
    }

    private void callBack() {
        ((SmsSendListener) context).onSmsSendEvent(wasSent);
        stop();
    }

    @Override
    public void onChange(boolean selfChange) {
        if (wasSent || timedOut)
            return;

        Cursor cursor = null;

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

            if (cursor != null && cursor.moveToFirst()) {
                final String address =
                    cursor.getString(cursor.getColumnIndex(COLUMN_ADDRESS));
                final int type =
                    cursor.getInt(cursor.getColumnIndex(COLUMN_TYPE));

                if (PhoneNumberUtils.compare(address, phoneNumber) &&
                        type == MESSAGE_TYPE_SENT) {

                    wasSent = true;
                    callBack();
                }
            }
        }
        finally {
            if (cursor != null) {
                cursor.close();
            }
        }
    }

    public interface SmsSendListener {
        // Passes true if the message was sent
        // Passes false if timed out
        public void onSmsSendEvent(boolean sent);
    }
}