In the Korean drama "from the stars", in order not to let thousands of Iraq to see the subconscious issued by the "confession" SMS, Wuli professors do not hesitate to use space shuttle and space static two big "kill"".
In fact, don't envy all professors, since the WeChat withdraw function, each WeChat users can be comparable to super ability, easy to withdraw message.
So, without the aid of super power, how can WeChat simultaneously withdraw information from both mobile phones?
Sending messages and withdrawing messages to MobileB with MobileA as an example:
When A and MobileA send messages, they will be generated on their own WeChat clientThe only UniqueMsgID in the worldAnd the UniqueMsgID is attached to the message body to be sent.
When B and MobileB receive messages, they store the message body and display the message.
When C and MobileA withdraw messages, MobileA knows the UniqueMsgID of each message body that they have sent, which needs to be withdrawn, and the UniqueMsgID of that message is attached to the withdrawal order.
D,When MobileB receives the withdrawal command, it finds the corresponding message body in its database according to the UniqueMsgID in the withdrawal command, and then displays the revocation effect.
Why can WeChat withdraw the message only 2 minutes?
The mobile Internet era to everyone in an asynchronous processing information era, most people over a period of time to process the message, in contrast, two minutes seems a bit too short, often encountered when you want to withdraw has only found over the period of dilemma.
So, do we need to set a deadline for withdrawal? The answer is undoubtedly yes.
In the dialogue, there are two hazards if the withdrawal time is not set:
A, the information sent, if not set a withdrawal time for some has been sent out for a long time, it is likely the recipient has seen the sender and back will make the relationship more awkward, even unnecessary misunderstanding.
After the B is sent and the information is sent, if the time is not limited, the sender can withdraw any historical message, which will lead to the incomplete context of the dialogue and affect the user experience.
So why is the withdrawal time 2 minutes? Can't you be more or less?
In this regard, WeChat product team big data analysis that, from the perspective of the recipient information, 2 minutes is the average reading a message from the receiver to the length of time, and the withdrawal time in 2 minutes, will maintain the maximum contextual integrity, giving a stable user experience.
If less than 2 minutes, the release of information itself may be too late to realize the information error, missed the opportunity to withdraw;
If the message is longer than 2 minutes, greatly enhance the probability of reading the receiver, the sender will no longer need to withdraw, withdraw and long time ago to send information will also destroy the contextual coherence, seriously affect the experience and effect of dialogue.
Compared to set a time limit, why not read in the withdrawal prompts the other function?
Although the average is 2 minutes from the received reading information when long, but we are not informed, the end will be issued to the information at the moment of reading, this will lead to the withdrawal function and sometimes is not so in a timely manner, and thus fall into the famous "Schrodinger cat" questions.
So why is WeChat not suggesting that the other party has read it in the withdrawal function? In this way, the sender can visually choose whether to withdraw or not.
If there is a reading cue, then the receiver will know that the sender already knows that he sees the message that the other party wants to withdraw, which makes the two sides more awkward.
Most of the time, the receiver does not want to let the sender know the if you have read the information, such as the common employee boss, the boss after the message is sent, if found employees have read this information but not reply (such as the date and so on), so the boss will inevitably produce for many, many years to come, discontent of employees.
But if you don't read and read, the boss doesn't know if employees are online, and employees don't have to stare at their phones all the time.
The product behind these settings is that WeChat does not want to put pressure on the receiver of the information. Compared with sender and receiver, WeChat pays more attention to the receiver's experience.
Why WeChat withdraw information to appear text prompt
Since the withdrawal of information provides a regret for the user, why does it leave behind the message "so and so a message was withdrawn"?
WeChat's news recall was sort of like an email withdrawal. In the moment of sending out, in fact, in the lock screen "notice" to each other, so it is difficult to achieve traceless.
The apple mobile phone as an example, as long as the WeChat's "notice details" open, and allow the mobile phone display WeChat "notice", so even if the withdrawal of the information, also can be in the apple mobile phone to check on the "notice":
Since everyone does not have a specific function of professors, so information conference will leave traces, but if the recipient received notification of opening and found no news that lost news, but to the sender repeat, this will make both sides more awkward.
In addition, in some business negotiations or lending and other specific occasions, if the withdrawal of information without text prompts, will lead to loss of interest of the other party.
For example, the borrowing problems mentioned by netizens:
From the development perspective, the birth of withdrawal function is for typos or email to the wrong person, consider the normal use of the scene.
For those special scenes (such as lovers quarrel, etc.), the user before the information is sent to try to restrain emotion, avoid "impulse", so as not to miss the withdrawal time, unfortunately lead to "cup"".