How does Apple choose a mobile phone card to send messages?

In fact, using the secondary card of Apple iPhone to send text messages does not need to be operated in the settings, but directly in the information APP. The specific method is as follows:

1. Open the information APP of iPhone, and click New Information in the upper right corner;

2. Enter or click+to enter the mobile phone number of the recipient, and then edit the message content;

3. Click the default SIM card, and a prompt to select the primary and secondary card numbers will pop up at the bottom of the screen. Select the secondary card number to switch to the secondary number to send short messages.

Extended data:

Tips to extend the life of iPhone battery;

1. Develop a good habit of charging.

When Apple's mobile phone prompts that the battery is low, charge it in time to avoid automatic shutdown due to low battery. If the battery efficiency is less than 80%, please try to replace the battery.

2. Turn on optimized charging

This function can intelligently learn and judge the user's usage and charging habits, so that the charging process is more balanced, thus slowing down the aging of the battery and improving the battery life to a certain extent.

How to View: The function of "Optimizing Battery Charging" can be viewed in Settings-Battery-Battery Health ~

3. The background application refresh is prohibited.

Applications use battery life when running in the background. You can see how long the application has been running in the background. If the application runs out of power when not in use, you can disable background application refresh to prevent it from running in the background. If the application consumes too much power, we can also choose to uninstall it!

4. Enable low battery mode

The "low battery mode" function can make the phone save more power. When the low battery mode is enabled, your screen will be slightly dimmed, limiting background processes, slightly slowing down the processor, or reducing the energy required by the device during normal use.

How to operate: The easiest way to enable this function is to slide down from the upper right corner of the iPhone, and then click the battery icon. It can also be set in >; Battery > enable low power mode in low power mode.

5. Turn off some app push.

Push application notifications, email reading notifications, etc. It will shorten the battery life, so it's best to turn it off if you want to make the iPhone battery life longer. You can edit each application and turn off notifications in Settings.