【Android】Fragmnet 片段 範例
Android Fragment 是一個可以被放置在 Android Activity 中的 UI 部件。它可以被用來組成多個頁面的應用程式,並且允許在不同的螢幕尺寸或設備上重用 UI。Fragment 可以被加入或移除,並且可以在不同的 Activity 之間共用。
它可以搭配 Android 的 FragmentManager 和 FragmentTransaction 類別來管理和操作。
![](https://developer.android.com/static/images/guide/fragments/fragment-screen-sizes.png)
文章目錄
- Fragment 創建
- Fragment 參數傳遞
- Fragment 添加依賴
- Developer Documents Fragment
1.Fragment 創建
fragment_first.xml
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent">
<androidx.appcompat.widget.AppCompatTextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="First"
android:textSize="50sp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
FirstFragment.kt
class FirstFragment : Fragment(R.layout.fragment_first) {
}
activity_main.xml
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<androidx.fragment.app.FragmentContainerView
android:id="@+id/fragment_container_view"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
MainActivity.kt
class MainActivity : AppCompatActivity(R.layout.activity_main) {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
if (savedInstanceState == null) {
supportFragmentManager.commit {
setReorderingAllowed(true)
add<FirstFragment>(R.id.fragment_container_view)
}
}
}
}
2.Fragment 參數傳遞
MainActivity.kt
class MainActivity : AppCompatActivity(R.layout.activity_main) {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
if (savedInstanceState == null) {
val bundle = bundleOf("number" to 5)
supportFragmentManager.commit {
setReorderingAllowed(true)
add<FirstFragment>(R.id.fragment_container_view, args = bundle)
}
}
}
}
FirstFragment.kt
class FirstFragment : Fragment(R.layout.fragment_first) {
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
val number = requireArguments().getInt("number")
Log.e("FirstFragment", number.toString())
}
}
3.Fragment 添加依賴
PersonData.kt
data class PersonData(val name: String, val age: Int)
FirstFragment.kt
class FirstFragment(private val personData: PersonData) : Fragment(R.layout.fragment_first) {
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
Log.e("FirstFragment", personData.toString())
}
}
FirstFragmentFactory.kt
class FirstFragmentFactory(private val personData: PersonData) : FragmentFactory() {
override fun instantiate(classLoader: ClassLoader, className: String): Fragment =
when (loadFragmentClass(classLoader, className)) {
FirstFragment::class.java -> FirstFragment(personData)
else -> super.instantiate(classLoader, className)
}
}
MainActivity.kt
class MainActivity : AppCompatActivity(R.layout.activity_main) {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
if (savedInstanceState == null) {
supportFragmentManager.fragmentFactory = FirstFragmentFactory(PersonData("wade", 26))
supportFragmentManager.commit {
add<FirstFragment>(R.id.fragment_container_view)
setReorderingAllowed(true)
}
}
}
}
4.Developer Documents Fragment
Open in Documents Fragment