How to turn a text file into a short message and send it by mobile phone?

You can do this in the following ways:

1. Open the text file, and then press and hold the contents of the file. At this point, all the roles are selected, and then let go of the selection "Copy".

2. Open the SMS editing window, click in the middle of the window and select "Paste" to successfully change the text content into SMS content and send it out.