To add a large number of contacts at one time, you can do it asynchronously in the background, and give a progress bar or other prompt on the front end to indicate the completion level, so that the user's operation will not be blocked and there will be no feeling of being stuck.
To add a large number of contacts at one time, you can do it asynchronously in the background, and give a progress bar or other prompt on the front end to indicate the completion level, so that the user's operation will not be blocked and there will be no feeling of being stuck.