作者:轰雷帝 | 来源:互联网 | 2022-12-05 17:43
1> aminography..:
我通过使用片段管理器隐藏和显示片段来处理这种情况。我编写了一个示例代码来处理它,如下所示。
class MainActivity : BaseActivity() {
private val homeFragment = HomeFragment.newInstance()
private val categoryFragment = CategoryFragment.newInstance()
private val searchFragment = SearchFragment.newInstance()
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
navigation.setOnNavigationItemSelectedListener(mOnNavigationItemSelectedListener)
navigation.menu.findItem(R.id.navigation_home).isChecked = true
supportFragmentManager.beginTransaction()
.add(R.id.containerFrameLayout, homeFragment)
.add(R.id.containerFrameLayout, categoryFragment)
.add(R.id.containerFrameLayout, searchFragment)
.commit()
setTabStateFragment(TabState.HOME).commit()
}
override fun onBackPressed() {
if (supportFragmentManager.backStackEntryCount > 0 || !homeFragment.isHidden) {
super.onBackPressed()
} else {
setTabStateFragment(TabState.HOME).commit()
navigation.menu.findItem(R.id.navigation_home).isChecked = true
}
}
private fun setTabStateFragment(state: TabState): FragmentTransaction {
supportFragmentManager.popBackStack(null, FragmentManager.POP_BACK_STACK_INCLUSIVE)
val transaction = supportFragmentManager.beginTransaction()
transaction.setCustomAnimations(R.anim.fragment_enter, R.anim.fragment_exit)
when (state) {
TabState.HOME -> {
transaction.show(homeFragment)
transaction.hide(categoryFragment)
transaction.hide(searchFragment)
}
TabState.CATEGORY -> {
transaction.hide(homeFragment)
transaction.show(categoryFragment)
transaction.hide(searchFragment)
}
TabState.SEARCH -> {
transaction.hide(homeFragment)
transaction.hide(categoryFragment)
transaction.show(searchFragment)
}
}
return transaction
}
private val mOnNavigationItemSelectedListener= BottomNavigationView.OnNavigationItemSelectedListener { item ->
when (item.itemId) {
R.id.navigation_home -> {
setTabStateFragment(TabState.HOME).commit()
return@OnNavigationItemSelectedListener true
}
R.id.navigation_category -> {
setTabStateFragment(TabState.CATEGORY).commit()
return@OnNavigationItemSelectedListener true
}
R.id.navigation_search -> {
setTabStateFragment(TabState.SEARCH).commit()
return@OnNavigationItemSelectedListener true
}
}
false
}
internal enum class TabState {
HOME,
CATEGORY,
SEARCH,
}
}