Android中的良好UI实践,是否有一些示例代码？

<android.support.design.widget.FloatingActionButton
    android:id="@+id/fab"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:src="@drawable/ic_add"
    app:backgroundTint="@color/colorAccent"
    app:fabSize="normal" />

<Button
    android:id="@+id/btn_submit"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Submit"
    android:textColor="@color/colorPrimary"
    android:background="@drawable/rounded_button" />

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical">

    <TextView
        android:id="@+id/tv_title"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Title"
        android:textSize="18sp" />

    <ImageView
        android:id="@+id/iv_image"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:src="@drawable/image"
        android:scaleType="centerCrop" />

</LinearLayout>

ObjectAnimator animator = ObjectAnimator.ofFloat(view, "alpha", 0f, 1f);
animator.setDuration(1000);
animator.start();

Toast.makeText(this, "Invalid input", Toast.LENGTH_SHORT).show();