Android Fragments 在导航抽屉Activity中更改片段(Kotlin)

dldeef67  于 2023-06-30  发布在  Android
关注(0)|答案(2)|浏览(130)

我刚刚开始使用FragmentsViewModels。我想替换Activity中的片段,该怎么做?
将Android和Fragments混合在一起的最佳方法是什么?

主活动

class MainActivity : AppCompatActivity(),NavigationView.OnNavigationItemSelectedListener {

    lateinit var drawerLayout: DrawerLayout
    lateinit var fragmentTransaction: FragmentTransaction

    private lateinit var appBarConfiguration: AppBarConfiguration

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

        val toolbar: Toolbar = findViewById(R.id.toolbar)
        setSupportActionBar(toolbar)

        drawerLayout= findViewById(R.id.drawer_layout)
        val navView: NavigationView = findViewById(R.id.nav_view)
        val navController = findNavController(R.id.nav_host_fragment)

        val toggle = ActionBarDrawerToggle(this,drawerLayout,toolbar,R.string.navigation_drawer_open,R.string.navigation_drawer_open)
            drawerLayout.addDrawerListener(toggle)
            toggle.syncState()

        // Passing each menu ID as a set of Ids because each
        // menu should be considered as top level destinations.
        appBarConfiguration = AppBarConfiguration(setOf(
                R.id.nav_home, R.id.nav_dersler, R.id.nav_soru,R.id.nav_socialmedia), drawerLayout)
        setupActionBarWithNavController(navController, appBarConfiguration)
        navView.setupWithNavController(navController)

        navView.setNavigationItemSelectedListener(this);

    }

    override fun onNavigationItemSelected(item: MenuItem): Boolean {
        when(item.itemId){
            R.id.nav_home -> {
                  //Toast.makeText(this,"Anasayfa",Toast.LENGTH_SHORT).show()
                }
                R.id.nav_socialmedia -> {
                    Toast.makeText(this,"Sosyal Medya Hesaplarımızı Takip Edebilirsiniz",Toast.LENGTH_SHORT).show()
                }

                R.id.nav_dersler -> {

                }
                R.id.nav_soru -> {

                }

            }
            drawerLayout.closeDrawer(GravityCompat.START)
            return true

        }

        override fun onCreateOptionsMenu(menu: Menu): Boolean {
            menuInflater.inflate(R.menu.main, menu)
            return true
        }



        override fun onOptionsItemSelected(item: MenuItem): Boolean {
             when(item.itemId){
                R.id.action_refresh -> {
                    Toast.makeText(this,"Refreshing...",Toast.LENGTH_SHORT).show()
                    val refreshActivity = intent
                    finish()
                    startActivity(refreshActivity)
                    true
                }

                else -> super.onOptionsItemSelected(item)
            }
            return true
        }

        override fun onSupportNavigateUp(): Boolean {
            val navController = findNavController(R.id.nav_host_fragment)
            return navController.navigateUp(appBarConfiguration) || super.onSupportNavigateUp()

        }

}

我有mobile_navigation.xml,但我不知道它是做什么的。谢谢你的帮助enter image description here

5jdjgkvh

5jdjgkvh1#

TL;DR:
Activity是在应用中制作屏幕的基础组件。Fragment是屏幕的一个动态部分,添加它是为了支持具有更大屏幕的平板电脑。
我们通常以这些方式合并它们:
1.一个Activity作为容器,所有屏幕表示为Fragment s
对于这种方法,您可以
自己实现它:
将片段添加到Activity堆栈:

supportFragmentManager
        .beginTransaction()
        .addToBackStack(null)
        .add(containerId, fragment, fragment::class.java.simpleName)
        .commit()

替换Activity中的片段:

supportFragmentManager
        .beginTransaction()
        .replace(containerId, fragment, fragment::class.java.simpleName)
        .commit()

但是Android引入了Android导航组件来处理所有这些添加、替换和回栈处理:
我建议使用这种方法,因为它更容易。LINK
1.使用多个活动和片段
对于使用BottomNavigation、NavigationDrawer和...的每个屏幕使用带有多个Fragment的Activity来表示其中的每个选项卡。
一个很好的教程可以在这里找到。LINK

9njqaruj

9njqaruj2#

类MainActivity:public void run(){

private lateinit var toggle: ActionBarDrawerToggle
lateinit var drawerLayout: DrawerLayout

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

     drawerLayout = findViewById(R.id.drawerLayout)
    val navView: NavigationView = findViewById(R.id.nav_view)

    toggle = ActionBarDrawerToggle(this,drawerLayout,R.string.open,R.string.close)
    drawerLayout.addDrawerListener(toggle)
    toggle.syncState()

    supportActionBar?.setDisplayHomeAsUpEnabled(true)
    navView.setNavigationItemSelectedListener {

        //now i want to highLight the particular item that is clicked
        it.isChecked =true

        when (it.itemId) {

            R.id.nav_home -> replaceFragment(HomeFragment(),it.title.toString())

            R.id.nav_message ->  replaceFragment(MessageFragment(),it.title.toString())

        }
        true
    }
}
//when the user tab any icons the fragment will open. So, we create a Method
private fun replaceFragment(fragment : Fragment, title: String)
{
    //get the reference from the FragmentManager
    val fragmentManager = supportFragmentManager
    val fragmentTransaction = fragmentManager.beginTransaction()
    fragmentTransaction.replace(R.id.frameLayout,fragment)
    fragmentTransaction.commit()
    //whenEver user click on the drawer the drawer is closed
    drawerLayout.closeDrawers()
    setTitle(title)

}

//override method
override fun onOptionsItemSelected(item: MenuItem): Boolean {
    if (toggle.onOptionsItemSelected(item)) {
        return true
    }
    return super.onOptionsItemSelected(item)
}}

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