安卓设备能否发送阅后即焚SMS？如何实现带EditText的自毁短信？

Hey there! Let's dive into how you can build that exact self-destructing SMS experience you described— the kind that pops up with a message (and even an input field for replies) without ever being saved to the recipient's inbox, and vanishes completely after being read.

Core Concept: WAP Push SMS #

The messages you're referring to aren't standard text SMS. They're WAP Push SMS (specifically Service Indication messages), a specialized SMS type that triggers system-level actions instead of being stored in the default messaging app's database. These messages are designed to be temporary: they show up in a dedicated system dialog/activity, and once dismissed, they're wiped from memory with no trace left in the inbox.

Step-by-Step Implementation #

1. Send the WAP Push Message #

To send this type of message, you'll use Android's SmsManager class to send a data SMS with a specific PDU (Protocol Data Unit) formatted to follow WAP-168 standards. Here's a simplified example:

First, add the required permission to your AndroidManifest.xml:

<uses-permission android:name="android.permission.SEND_SMS" />

(Note: For Android 6.0+, you'll need to request this permission dynamically at runtime.)

Then, construct and send the WAP Push PDU:

import android.telephony.SmsManager;

public class SelfDestructSmsSender {
    public void sendTemporaryMessage(String phoneNumber, String messageContent) {
        SmsManager smsManager = SmsManager.getDefault();
        // Construct WAP Push PDU (follows WAP Service Indication spec)
        byte[] wapPushPdu = buildWapPushPdu(messageContent);
        
        // Send as data SMS to port 9200 (standard WAP Push port)
        smsManager.sendDataMessage(phoneNumber, null, (short) 9200, wapPushPdu, null, null);
    }

    private byte[] buildWapPushPdu(String message) {
        // Simplified PDU construction (full implementation needs to follow WAP-168)
        // This example creates a temporary service indication message
        String wapHeader = "0605040B8423F0";
        String encodedMessage = encodeMessageToWapFormat(message);
        String fullPdu = wapHeader + encodedMessage;
        
        // Convert hex string to byte array
        int len = fullPdu.length();
        byte[] data = new byte[len / 2];
        for (int i = 0; i < len; i += 2) {
            data[i / 2] = (byte) ((Character.digit(fullPdu.charAt(i), 16) << 4)
                                 + Character.digit(fullPdu.charAt(i+1), 16));
        }
        return data;
    }

    private String encodeMessageToWapFormat(String message) {
        // Implement proper WAP encoding (UTF-8 or GSM 03.38)
        // For simplicity, this is a placeholder— use a library or full spec implementation
        StringBuilder sb = new StringBuilder();
        for (char c : message.toCharArray()) {
            sb.append(String.format("%02X", (int) c));
        }
        return sb.toString();
    }
}

2. Recipient-Side Behavior #

When the recipient receives this WAP Push SMS:

• Android's system will automatically launch a temporary dialog or activity (depending on the device manufacturer) to display the message.
• If your PDU includes parameters for a reply field, the system will show an input box for the user to respond.
• Critically, this message is never saved to the device's SMS database. Once the user closes the dialog, the message is immediately removed from memory— no trace remains in the default messaging app.

3. Key Considerations #

• Device Compatibility: Some Android OEMs modify how WAP Push messages are handled. Test across multiple devices to ensure consistent behavior.
• Reply Handling: If you want replies to also be self-destructing, the recipient's response needs to be sent using the same WAP Push method (not standard SMS).
• PDU Accuracy: The full WAP Push PDU requires strict adherence to the WAP-168 specification. For production use, consider using a dedicated library or referencing official WAP documentation to avoid formatting errors.

Why Third-Party Apps Don't Fit Your Need #

Most self-destructing message apps rely on their own cloud servers or encrypted peer-to-peer channels. What you're looking for is a native SMS-based solution that leverages WAP Push standards— no third-party services required, and no data stored on either device.

内容的提问来源于stack exchange，提问作者user1733984