Android Fragment.hide()不隐藏我的片段
我已经实现了Android Fragment.hide()不隐藏我的片段,android,xml,android-fragments,kotlin,Android,Xml,Android Fragments,Kotlin,我已经实现了hide()Fragment的最基本形式,但它根本不起作用 我的初始onCreate()将所有3个片段添加到活动中(它们都同时显示)。然后,当单击导航项时,我对两个片段调用hide(),但是它们不会从屏幕上消失,没有任何变化 我的活动: class TruthOrDare : FragmentActivity(), BottomNavigationView.OnNavigationItemSelectedListener { override fun onCreate(s
hide()
Fragment的最基本形式,但它根本不起作用
我的初始onCreate()
将所有3个片段添加到活动中(它们都同时显示)。然后,当单击导航项时,我对两个片段调用hide()
,但是它们不会从屏幕上消失,没有任何变化
我的活动:
class TruthOrDare : FragmentActivity(), BottomNavigationView.OnNavigationItemSelectedListener {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_truth_or_dare)
bottomNav_truthordare.setOnNavigationItemSelectedListener(this)
bottomNav_truthordare.selectedItemId = R.id.action_game
if (savedInstanceState != null) {
return
}
firstFragment.arguments = intent.extras
val transaction = supportFragmentManager.beginTransaction()
transaction.add(R.id.fragment_layout, GameFragment())
transaction.add(R.id.fragment_layout, LeaderboardsFragment())
transaction.add(R.id.fragment_layout, OptionsFragment())
transaction.commit()
}
override fun onNavigationItemSelected(item: MenuItem): Boolean {
val transaction = supportFragmentManager.beginTransaction()
transaction.hide(GameFragment())
transaction.hide(OptionsFragment())
transaction.commit()
return true
}
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/layout_truthordare"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:animateLayoutChanges="true"
tools:context=".TruthOrDare">
<android.support.v7.widget.Toolbar
android:id="@+id/toolbar_truthordare"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="@color/colorPrimaryDark"
android:elevation="4dp"
android:theme="@style/ThemeOverlay.AppCompat.ActionBar"
app:layout_constraintTop_toTopOf="parent"
app:popupTheme="@color/colorPrimaryDark"
app:title="Level 1" />
<FrameLayout
android:id="@+id/fragment_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_above="@id/bottomNav_truthordare" android:layout_below="@id/toolbar_truthordare">
</FrameLayout>
<android.support.design.widget.BottomNavigationView
android:id="@+id/bottomNav_truthordare"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@color/colorPrimaryDark"
app:itemIconTint="@color/bottom_nav_items"
app:itemTextColor="@color/bottom_nav_items"
android:layout_alignParentBottom="true"
app:menu="@menu/menu" />
</RelativeLayout>
我的XML:
class TruthOrDare : FragmentActivity(), BottomNavigationView.OnNavigationItemSelectedListener {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_truth_or_dare)
bottomNav_truthordare.setOnNavigationItemSelectedListener(this)
bottomNav_truthordare.selectedItemId = R.id.action_game
if (savedInstanceState != null) {
return
}
firstFragment.arguments = intent.extras
val transaction = supportFragmentManager.beginTransaction()
transaction.add(R.id.fragment_layout, GameFragment())
transaction.add(R.id.fragment_layout, LeaderboardsFragment())
transaction.add(R.id.fragment_layout, OptionsFragment())
transaction.commit()
}
override fun onNavigationItemSelected(item: MenuItem): Boolean {
val transaction = supportFragmentManager.beginTransaction()
transaction.hide(GameFragment())
transaction.hide(OptionsFragment())
transaction.commit()
return true
}
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/layout_truthordare"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:animateLayoutChanges="true"
tools:context=".TruthOrDare">
<android.support.v7.widget.Toolbar
android:id="@+id/toolbar_truthordare"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="@color/colorPrimaryDark"
android:elevation="4dp"
android:theme="@style/ThemeOverlay.AppCompat.ActionBar"
app:layout_constraintTop_toTopOf="parent"
app:popupTheme="@color/colorPrimaryDark"
app:title="Level 1" />
<FrameLayout
android:id="@+id/fragment_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_above="@id/bottomNav_truthordare" android:layout_below="@id/toolbar_truthordare">
</FrameLayout>
<android.support.design.widget.BottomNavigationView
android:id="@+id/bottomNav_truthordare"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@color/colorPrimaryDark"
app:itemIconTint="@color/bottom_nav_items"
app:itemTextColor="@color/bottom_nav_items"
android:layout_alignParentBottom="true"
app:menu="@menu/menu" />
</RelativeLayout>
有人能告诉我为什么
hide()
不起作用吗?您试图隐藏不同于在onCreate()
中创建和处理的实例。请保留对您在onCreate()
中创建的对象的引用,或将标记添加到它们的事务中,然后使用FragmentManager\findFragmentByTag()
将它们放入onNavigationItemSelected()
。谢谢transaction.add(R.id.fragment\u布局,GameFragment(),“add\u game”)
和val game=supportFragmentManager.findFragmentByTag(“add\u game”)
工作正常。您试图隐藏的实例与在onCreate()
中创建和处理的实例不同。请保留对您在onCreate()
中创建的对象的引用,或将标记添加到它们的事务中,然后使用FragmentManager\findFragmentByTag()
将它们放入onNavigationItemSelected()
。谢谢transaction.add(R.id.fragment\u布局,GameFragment(),“add\u game”)
和val game=supportFragmentManager.findFragmentByTag(“add\u game”)
效果完美。