How does iPhone prevent contacts from making phone calls and texting? Will he know that he is blocked after sending a text message?

After shielding, the other party will not notice anything. Take the iPhone 6 as an example. The specific operation steps are as follows:

1, the first step is to open the settings option of the mobile phone desktop.

2. After opening the settings page, click to enter the "do not disturb mode" option, as shown below.

3. In the DND mode interface, select the switch button behind DND mode, as shown in the figure below.

4. Then select and click the "Allow the following calls" option below.

5. Finally, click the All Contacts option.