Android:ems= "10" in the Android XML layout file

Width is 10 characters wide

The Android:ems property in XML, as the default generated property of EditText, is the length of the string that needs to be edited.
Set to 10 o'clock, edit up to 10 em, an EM unit is two inch, but with auto Adjust, em in Android represents the number of ' M '.
However, the properties of EditText are only displayed when Android:layout_width= "Wrap_content".
If it is android:layout_width= "match_parent", there will be no change.

Android:ems= "10" in the Android XML layout file