Android - Button去掉預設的陰影

style="?android:attr/borderlessButtonStyle"

<Button android:id="@+id/button_send"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:text="@string/button_send"

android:onClick="sendMessage"

style="?android:attr/borderlessButtonStyle" />

Button去掉預設的陰影