/*只能读*/
.read-only {
  -webkit-user-modify:read-only;
  -moz-user-modify:read-only;
  user-modify:read-only;
}
/*可读可写*/
.read-write {
  -webkit-user-modify: read-write;
  -moz-user-modify: read-write;
  user-modify: read-write;
}
/*只可写*/
.write-only {
  -webkit-user-modify: write-only;
  -moz-user-modify: write-only;
  user-modify: write-only;
}