这个问题在这里已有答案:
请帮忙怎么做这样的设计!
根据documentation,这应该足够了:
<android.support.design.widget.TextInputLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="Remarks">
<android.support.design.widget.TextInputEditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="@string/form_username"/>
</android.support.design.widget.TextInputLayout>