接下來要實作跳轉之後的activty連接著viewpager跟tabitem去對應到相對的fragment
首先先跳轉到一個新的activity

<Button
    android:id="@+id/next"
    android:layout_width="0dp"
    android:layout_weight="1"
    android:layout_height="wrap_content"
    android:text="next"/>
binding.next.setOnClickListener {
    start(FragmentActivity::class.java)
}

那這邊說一下這個start是我在第十天的時候有說道的baseactivity那今天使用的時候發現了一個bug，修改完後應該是長這樣

protected fun start(next: Class<*>, bundle: Bundle?, finished: Boolean) {
    val intent = Intent(this, next)
    if(bundle == null)intent.putExtras(Bundle())
    else intent.putExtras(bundle)
    startActivity(intent)
    if (finished) this.finish()
}

intent到的next應該要是我上面傳入的建構值而不是新增一個
那接著是新的activity的xml

<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">
    <data>
        <variable
            name="viewmodel"
            type="com.example.myapplication.FragmentViewModel" />
    </data>
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">
        <androidx.viewpager.widget.ViewPager
            android:layout_width="match_parent"
            android:layout_height="0dp"
            android:layout_weight="1"/>
        <com.google.android.material.tabs.TabLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content">
            <com.google.android.material.tabs.TabItem
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="1"/>
            <com.google.android.material.tabs.TabItem
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="2"/>
            <com.google.android.material.tabs.TabItem
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="3"/>
        </com.google.android.material.tabs.TabLayout>
    </LinearLayout>

</layout>

再來是activity

class FragmentActivity : BaseActiivity(){
    private val fragmentViewModel by lazy {
        initViewModel(application , FragmentViewModel::class.java)
    }

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        val binding = DataBindingUtil.setContentView<ActivityFragmentBinding>(this,R.layout.activity_fragment)
        binding.lifecycleOwner = this
        binding.viewmodel = fragmentViewModel
    }
}

跳轉之後就長這樣啦