Wechat messages can be deleted directly after being sent. Is there no hint across the street?

No, you send a message to the background server first, and the server will send it to the person you want to send after receiving your message. There is a transit process. Delete it after sending it. If the message is intercepted before it is sent to the server (when your network card is used), you can not display it, but the other party has received your message reminder, and you have no right to cancel the action sent by the server to the other party.