下記対応表 | operator | 変換後| |----------|-------| | & | & | | < | < | | > | > | | " | " | | ' | ' | <EditText android:id="@+id/edit_mail" android:text="@={mail}" /> <Button androidtext="保存" android:enabled="@{mail.length > 0 &amp;&amp; isEmailValid(mail)}" /></button></edittext>