Fragment: bu nima, fragmentlar va Android-da FragmentManager

Fragment nima?

Fragment — Activity ichida ekranning bir qismini ifodalovchi modulli Android foydalanuvchi interfeysi komponenti. Fragment o'z layoutini boshqarishi, hayot sikli hodisalarini qayta ishlashi va o'z holatini saqlashi mumkin. Modulligi tufayli bitta fragment turli Activity larda va turli qurilmalarda ishlatilishi mumkin.

Fragment API Android 3.0 (Honeycomb, API 11) 2011 yilda planshetlarni qo'llab-quvvatlash uchun paydo bo'ldi. Bungacha dasturchilar telefon va planshet uchun alohida Activity lar yaratishlari kerak edi. Fragment ekranni mustaqil bloklardan yig'ish imkonini berdi. 2019 yilda Google API 4 gacha orqaga moslik bilan Jetpack Fragment kutubxonasini chiqardi.

Google ma'lumotlariga ko'ra (2026), Google Play-dagi ilovalarning 80% i Fragment dan u yoki bu shaklda foydalanadi. Jetpack Fragment kutubxonasi Google Play Services orqali 10 milliard martadan ko'proq yuklab olingan. Fragment Jetpack Compose davrida ham Android arxitekturasining asosiy komponenti bo'lib qolmoqda.

Fragment hayot sikli

Fragment hayot sikli Activity nikiga qaraganda murakkabroq, chunki u xo'jayin Activity holatiga bog'liq. Fragment Activity bilan bir xil holatlardan o'tadi, lekin o'z callback larini qo'shadi: onAttach, onCreateView, onViewCreated, onActivityCreated, onDestroyView, onDetach.

Fragment va Activity hayot sikli solishtirish

Fragment hayot sikli ning asosiy farqi — onCreate va onDestroy o'rtasida onCreateView va onDestroyView chaqirilishi. Fragment UI siz mavjud bo'lishi mumkin (agar onCreateView null qaytarsa). Activity qayta yaratilgandan so'ng FragmentManager fragmentlarni avtomatik tiklaydi.

FragmentManager va tranzaksiyalar

FragmentManager — Activity da fragmentlarni boshqarish uchun markaziy sinf. U fragmentlarni qo'shish, o'chirish, almashtirish, orqaga stekini boshqarish va holatni tiklash uchun javobgardir. FragmentManager supportFragmentManager (AndroidX) yoki fragmentManager (eski API) orqali olinadi.

class MainActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        // Agar fragment hali qo'shilmagan bo'lsa — yaratamiz
        if (savedInstanceState == null) {
            val transaction = this.supportFragmentManager
                .beginTransaction()
            transaction.add(R.id.fragment_container, ListFragment())
            transaction.addToBackStack(null)
            transaction.commit()
        }
    }

    fun replaceFragment(fragment: Fragment) {
        supportFragmentManager.beginTransaction()
            .replace(R.id.fragment_container, fragment)
            .addToBackStack(null)
            .commit()
    }
}

FragmentTransaction tranzaksiyalari — atomikdir. commit() bajarishni keyingi Looper sikluga rejalashtiradi. Darhol bajarish uchun commitNow() dan foydalaning. addToBackStack(null) tranzaksiyani orqaga stekiga qo'shadi — «Orqaga» tugmasi operatsiyani bekor qiladi.

Fragment hayot sikli metodlari

Kotlin misoli bilan Fragment hayot sikli ning asosiy metodlarini ko'rib chiqaylik. onCreateView layout yaratadi — Activity dan farqli ravishda metod View qaytarishi kerak. onViewCreated darhol keyin chaqiriladi, bu yerda elementlarni id bo'yicha topish xavfsiz. onDestroyView — view havolalarini tozalash uchun oxirgi imkoniyat.

class DetailFragment : Fragment() {

    private var _binding: FragmentDetailBinding? = null
    private val binding get() = _binding!!

    override fun onCreateView(
        inflater: LayoutInflater,
        container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View {
        _binding = FragmentDetailBinding.inflate(inflater, container, false)
        return binding.root
    }

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)
        binding.textTitle.setText("Tafsilotlar")
    }

    override fun onDestroyView() {
        super.onDestroyView()
        _binding = null
    }
}

View Binding namunasi _binding/binding bilan onDestroyView dan keyin layout havolasi nolga tushirilishini kafolatlaydi. View yo'q qilingandan keyin binding ga murojaat qilish NullPointerException keltirib chiqaradi. Bu namuna Google tomonidan barcha fragmentlar uchun tavsiya etiladi.

Fragmentlar o'rtasida ma'lumot uzatish

Fragmentlar o'rtasida ma'lumot uzatish uchun Android bir necha mexanizmlarni taklif qiladi. Eng ishonchlisi — bitta Activity fragmentlari o'rtasida taqsimlanadigan umumiy ViewModel. Fragment Result API bir martalik hodisalar uchun mos keladi. Bundle argumentlari — fragment yaratilganda ma'lumotlar uchun.

// Ikki fragment uchun umumiy ViewModel
class SharedViewModel : ViewModel() {
    private val _selectedItem = MutableLiveData<Item>()
    val selectedItem: LiveData<Item> = _selectedItem

    fun select(item: Item) { _selectedItem.setValue(item) }
}

// Fragment A: Fragment Result API orqali hodisa yuboradi
setFragmentResult("request_key", bundleOf("key" to "value"))

// Fragment B: hodisani qabul qiladi
childFragmentManager.setFragmentResultListener("request_key", this) { requestKey, bundle ->
    val value = bundle.getString("key")
}

Fragment Result API (Fragment 1.3.0 da qo'shilgan) eskirgan setTargetFragment/onActivityResult o'rnini egallaydi. API tip xavfsiz, Bundle ishlatadi va qabul qiluvchi haqida ma'lumot talab qilmaydi. Parent FragmentManager fragmentlar o'rtasida vositachi rolini o'ynaydi.

Fragment vs Activity: qachon nima tanlash

Fragment va Activity o'rtasidagi tanlov ilova arxitekturasiga bog'liq. Fragment adaptiv layoutlar (telefon + planshet), moslashtirilgan o'tish animatsiyalari va Jetpack Navigation dan foydalanish uchun majburiydir. Activity bir-ikki ekranli oddiy ilovalar uchun afzalroq.

Jetpack Fragment va Jetpack Navigation

Fragment bilan ishlashning zamonaviy yondashuvi — FragmentManager ni qo'lda boshqarish o'rnini bosadigan Jetpack Navigation Component. Kutubxona NavGraph (XML navigatsiya grafi), NavHostFragment va tip xavfsiz ma'lumot uzatish uchun Safe Args ni taqdim etadi.

Jetpack Fragment kutubxonasi (androidx.fragment:fragment-ktx) FragmentResult API, DialogFragment, BottomSheetDialogFragment va Lifecycle-aware komponentlari bilan integratsiyani o'z ichiga oladi. 2026 yildan Google Fragment dan to'g'ridan-to'g'ri emas, faqat Jetpack Navigation orqali foydalanishni tavsiya qiladi.

<navigation xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    app:startDestination="@+id/listFragment">

    <fragment
        android:id="@+id/listFragment"
        android:name=".ListFragment"
        android:label="Ro'yxat">
        <action
            android:id="@+id/action_list_to_detail"
            app:destination="@+id/detailFragment" />
    </fragment>

    <fragment
        android:id="@+id/detailFragment"
        android:name=".DetailFragment"
        android:label="Tafsilotlar" />
</navigation>