blocks|key|2712249|text|将其分离并附加|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2712250|Fragment+currentFragment+=+getFragmentManager().findFragmentByTag("YourFragmentTag");
FragmentTransaction+fragmentTransaction+=+getFragmentManager().beginTransaction();
fragmentTransaction.detach(currentFragment);
fragmentTransaction.attach(currentFragment);
fragmentTransaction.commit();|code-block|syntax|javascript|2712251|或使用搜索片段|2712252|Fragment+currentFragment+=+getActivity().getSupportFragmentManager().findFragmentById(R.id.container);|2712253|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

Detach and attach it with

<pre><code>Fragment currentFragment = getFragmentManager().findFragmentByTag("YourFragmentTag");
FragmentTransaction fragmentTransaction = getFragmentManager().beginTransaction();
fragmentTransaction.detach(currentFragment);
fragmentTransaction.attach(currentFragment);
fragmentTransaction.commit();
</code></pre>

or search fragment with

<pre><code>Fragment currentFragment = getActivity().getSupportFragmentManager().findFragmentById(R.id.container);
</code></pre>

blocks|key|35476|text|有一种非常有用的Fragment方法，可用于刷新片段。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|35477|@Override
public+void+setUserVisibleHint(boolean+isVisibleToUser)+{
++++super.setUserVisibleHint(isVisibleToUser);
++++if+(isVisibleToUser)+{
++++++++//Write+down+your+refresh+code+here,+it+will+call+every+time+user+come+to+this+fragment.+
+++++++//If+you+are+using+listview+with+custom+adapter,+just+call+notifyDataSetChanged().+
++++}
}|code-block|syntax|javascript|35478|entityMap^0|8|8|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|P|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|Q|8|@]|D|@]|E|$]]]|L|$]]

There is one very useful method of <code>Fragment</code>, which can be used for refreshing fragment.

<pre><code>@Override
public void setUserVisibleHint(boolean isVisibleToUser) {
 super.setUserVisibleHint(isVisibleToUser);
 if (isVisibleToUser) {
 //Write down your refresh code here, it will call every time user come to this fragment. 
 //If you are using listview with custom adapter, just call notifyDataSetChanged(). 
 }
}
</code></pre>

blocks|key|34924|text|组合了两个答案并删除了if+(isVisibleToUser)，因为它使setUserVisibleHint以不可预测的异步顺序调用，片段既可以刷新，也可以不刷新。我发现这段代码(在你的片段中)是稳定的：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|34925|@Override
public+void+setUserVisibleHint(boolean+isVisibleToUser)+{

super.setUserVisibleHint(isVisibleToUser);

++//+Refresh+tab+data:

++if+(getFragmentManager()+!=+null)+{

++++getFragmentManager()
++++++.beginTransaction()
++++++.detach(this)
++++++.attach(this)
++++++.commit();
++}
}|code-block|syntax|javascript|34926|entityMap^0|B|K|10|I|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]|$9|P|A|Q|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|R|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|S|8|@]|D|@]|E|$]]]|L|$]]

Combined two answers and removed <code>if (isVisibleToUser)</code>, because it makes the <code>setUserVisibleHint</code> be called in an unpredicted asynchroneous order and fragment can either be refreshed or not. I found this piece of code stable (in your Fragment):

<pre><code>@Override
public void setUserVisibleHint(boolean isVisibleToUser) {

super.setUserVisibleHint(isVisibleToUser);

 // Refresh tab data:

 if (getFragmentManager() != null) {

 getFragmentManager()
 .beginTransaction()
 .detach(this)
 .attach(this)
 .commit();
 }
}
</code></pre>

blocks|key|35522|text|当片段中的数据发生更改时，分离片段并将其重新附加到framelayout中始终是一个好主意。在我的例子中，我有一个listview，它显示我的用户最喜欢的项目。一旦用户与某个产品不同，我就必须将其从列表中删除并重新加载Favorites片段。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|35523|因此，我做了一些类似的操作，将片段重新加载到框架布局中：|35524|FragmentTransaction+ft+=+getFragmentManager().beginTransaction();
ft.replace(R.id.frm,new+FavoritesFragment()).addToBackStack(null).commit();|code-block|syntax|javascript|35525|这里，frm是保存片段的MainActivity中的帧布局，FavoritesFragment()是需要重新加载的片段。|35526|上述代码应该在用户每次按下unlike按钮时执行|35527|entityMap^0|P|B|1L|8|31|9|0|0|0|3|3|C|C|U|J|0|D|6|0^^$0|@$1|2|3|4|5|6|7|S|8|@$9|T|A|U|B|C]|$9|V|A|W|B|C]|$9|X|A|Y|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|Z|8|@]|D|@]|E|$]]|$1|H|3|I|5|J|7|10|8|@]|D|@]|E|$K|L]]|$1|M|3|N|5|6|7|11|8|@$9|12|A|13|B|C]|$9|14|A|15|B|C]|$9|16|A|17|B|C]]|D|@]|E|$]]|$1|O|3|P|5|6|7|18|8|@$9|19|A|1A|B|C]]|D|@]|E|$]]|$1|Q|3|-4|5|6|7|1B|8|@]|D|@]|E|$]]]|R|$]]

When the data in a fragment changes, its always a good idea to detach and reattach the fragment into the <code>framelayout</code>. In my case, I have a <code>listview</code> which shows the favorite items of my users. Once the user unlike a product, I have to remove it from the list and reload the <code>Favorites</code> fragment.

So I did something like this to reload the fragment into the frame layout:

<pre><code>FragmentTransaction ft = getFragmentManager().beginTransaction();
ft.replace(R.id.frm,new FavoritesFragment()).addToBackStack(null).commit();
</code></pre>

Here, <code>frm</code> is the frame layout in the <code>MainActivity</code> that hold the fragment and <code>FavoritesFragment()</code> is the fragment that needs to be reloaded.

The above code should be executed everytime the user press <code>unlike</code> button

blocks|key|2712337|text|根据FragmentTransaction#replace的说法，这等同于调用remove，然后调用add。因此，当您启动片段或想要重新加载它时，可以将.replace与片段管理器一起使用。因此，在onCreate中使用相同的函数，以及您想要重新加载它的位置...|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|2712338|@Override
protected+void+onCreate(Bundle+savedInstanceState)+{
++++super.onCreate(savedInstanceState);
++++setContentView(R.layout.activity_main);

++++if+(savedInstanceState+==+null)+{
++++++++loadContentFragment();
++++}
}

private+void+someFunctionThatChangesValue(String+value)+{
++++mValue+=+value;
++++loadContentFragment();
}

private+void+loadContentFragment()+{
++++ContentListFragment+newFrag+=+ContentListFragment.newInstance();
++++//+passing+value+from+activity
++++Bundle+args+=+new+Bundle();
++++args.putString(Constants.ARG_ACCOUNT_NAME,+mValue);
++++newFrag.setArguments(args);
++++getSupportFragmentManager().beginTransaction()
++++++++++++.replace(R.id.content_frag_container,
++++++++++++++++++++newFrag,
++++++++++++++++++++Constants.CONTENT_FRAGMENT)
++++++++++++.commitNow();
}|code-block|syntax|javascript|2712339|这样，只有一个函数可以加载内容并传递数据。这里假设您的布局中有一个ID为content_frag_container的条目。我用的是FrameLayout。|2712340|entityMap|0|LINK|mutability|MUTABLE|url|https://developer.android.com/reference/android/support/v4/app/FragmentTransaction#replace^0|24|8|2R|8|2|R|0|0|0|10|M|0^^$0|@$1|2|3|4|5|6|7|U|8|@$9|V|A|W|B|C]|$9|X|A|Y|B|C]]|D|@$9|Z|A|10|1|11]]|E|$]]|$1|F|3|G|5|H|7|12|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|13|8|@$9|14|A|15|B|C]]|D|@]|E|$]]|$1|M|3|-4|5|6|7|16|8|@]|D|@]|E|$]]]|N|$O|$5|P|Q|R|E|$S|T]]]]

According to <a href="https://developer.android.com/reference/android/support/v4/app/FragmentTransaction#replace" rel="nofollow noreferrer">FragmentTransaction#replace</a> it's the same as calling remove and then add. So you can use <code>.replace</code> with the fragment manager when you're starting the fragment or when you want to reload it. So use the same function from the <code>onCreate</code> as well as the place where you'd want to reload it...

<pre><code>@Override
protected void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.activity_main);

 if (savedInstanceState == null) {
 loadContentFragment();
 }
}

private void someFunctionThatChangesValue(String value) {
 mValue = value;
 loadContentFragment();
}

private void loadContentFragment() {
 ContentListFragment newFrag = ContentListFragment.newInstance();
 // passing value from activity
 Bundle args = new Bundle();
 args.putString(Constants.ARG_ACCOUNT_NAME, mValue);
 newFrag.setArguments(args);
 getSupportFragmentManager().beginTransaction()
 .replace(R.id.content_frag_container,
 newFrag,
 Constants.CONTENT_FRAGMENT)
 .commitNow();
}
</code></pre>

This way there's only one function that loads the content and passes data. This assumes you have an entry in your layout with the ID <code>content_frag_container</code>. I used a FrameLayout.

blocks|key|35211|text|此方法适用于我：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|35212|MyCameraFragment+f2+=+new+MyCameraFragment();
FragmentTransaction+transaction+=+getSupportFragmentManager().beginTransaction();
transaction.replace(R.id.frame_container,+f2);
transaction.addToBackStack(null);
transaction.commit();|code-block|syntax|javascript|35213|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

This method works for me:

<pre><code>MyCameraFragment f2 = new MyCameraFragment();
FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
transaction.replace(R.id.frame_container, f2);
transaction.addToBackStack(null);
transaction.commit();
</code></pre>

blocks|key|2712456|text|下面的代码刷新来自withIn适配器的片段|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2712457|DownloadsAdapter代码：|offset|length|style|BOLD|2712458|public+class+DownloadsAdapter+extends+RecyclerView.Adapter<DownloadsAdapter.ViewHolder>+{

private+Context+mCtx;

//getting+the+context+and+product+list+with+constructor
public+DownloadsAdapter(Context+mCtx,+List<DataModel>+fileUrlLinkList)+{
++++this.mCtx+=+mCtx;
++++this.fileUrlList+=+fileUrlLinkList;

}

**...+and+in+onBindViewHolder**

+FragmentManager+manager+=+((AppCompatActivity)+mCtx).getSupportFragmentManager();
+Fragment+currentFragment+=+manager.findFragmentByTag("DOWNLOADS");
+FragmentTransaction+fragmentTransaction+=+manager.beginTransaction();
+fragmentTransaction.detach(currentFragment);
+fragmentTransaction.attach(currentFragment);
+fragmentTransaction.commit();

...

}|code-block|syntax|javascript|2712459|entityMap^0|0|0|J|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|P|8|@$D|Q|E|R|F|G]]|9|@]|A|$]]|$1|H|3|I|5|J|7|S|8|@]|9|@]|A|$K|L]]|$1|M|3|-4|5|6|7|T|8|@]|9|@]|A|$]]]|N|$]]

Following code refreshes A fragment from withIn an Adapter

DownloadsAdapter code:

<pre><code>public class DownloadsAdapter extends RecyclerView.Adapter&lt;DownloadsAdapter.ViewHolder&gt; {

private Context mCtx;

//getting the context and product list with constructor
public DownloadsAdapter(Context mCtx, List&lt;DataModel&gt; fileUrlLinkList) {
 this.mCtx = mCtx;
 this.fileUrlList = fileUrlLinkList;

}

**... and in onBindViewHolder**

 FragmentManager manager = ((AppCompatActivity) mCtx).getSupportFragmentManager();
 Fragment currentFragment = manager.findFragmentByTag("DOWNLOADS");
 FragmentTransaction fragmentTransaction = manager.beginTransaction();
 fragmentTransaction.detach(currentFragment);
 fragmentTransaction.attach(currentFragment);
 fragmentTransaction.commit();

...

}
</code></pre>

blocks|key|35039|text|如果你对上面列出的一些方法有问题(就像我在升级之后...)，我建议在fragment中创建某种公共刷新方法，然后简单地调用它，它的代码更少，更好，更快，因为fragment不需要重新初始化……|type|unstyled|depth|inlineStyleRanges|entityRanges|data|35040|FragmentManager+fm+=+getSupportFragmentManager();

//if+you+added+fragment+via+layout+xml
Fragment+fragment+=+fm.findFragmentById(R.id.your_fragment_id);
if(fragment+instanceof+YourFragmentClass)+//+avoid+crash+if+cast+fail
{
++++((YourFragmentClass)fragment).showPrayer();
}|code-block|syntax|javascript|35041|如果您通过代码添加了片段，并在添加片段时使用了标记字符串，请改用findFragmentByTag：|35042|Fragment+fragment+=+fm.findFragmentByTag("yourTag");
if(fragment+instanceof+YourFragmentClass)
{
++++((YourFragmentClass)fragment).showPrayer();
}|35043|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

If you have problems with some of the methods listed above (as I had after uprgrading...), I recommend to make some kind of public refresh method in fragment and then simply call it, it is even less code, nicer and faster because fragment doesn't need to be reinitialized... 

<pre><code>FragmentManager fm = getSupportFragmentManager();

//if you added fragment via layout xml
Fragment fragment = fm.findFragmentById(R.id.your_fragment_id);
if(fragment instanceof YourFragmentClass) // avoid crash if cast fail
{
 ((YourFragmentClass)fragment).showPrayer();
}
</code></pre>

If you added fragment via code and used a tag string when you added your fragment, use findFragmentByTag instead:

<pre><code>Fragment fragment = fm.findFragmentByTag("yourTag");
if(fragment instanceof YourFragmentClass)
{
 ((YourFragmentClass)fragment).showPrayer();
}
</code></pre>

blocks|key|35045|text|在要刷新的片段中设置|type|unstyled|depth|inlineStyleRanges|entityRanges|data|35046|++++override+fun+setUserVisibleHint(isVisibleToUser:+Boolean)+{
++++super.setUserVisibleHint(isVisibleToUser)
++++if(isVisibleToUser){
++++++++if+(getFragmentManager()+!=+null)+{
++++++++++++getFragmentManager()
++++++++++++++++?.beginTransaction()
++++++++++++++++?.detach(this)
++++++++++++++++?.attach(this)
++++++++++++++++?.commit();
++++++++}
++++}
}|code-block|syntax|javascript|35047|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

set in Fragment that you want to refresh

<pre><code> override fun setUserVisibleHint(isVisibleToUser: Boolean) {
 super.setUserVisibleHint(isVisibleToUser)
 if(isVisibleToUser){
 if (getFragmentManager() != null) {
 getFragmentManager()
 ?.beginTransaction()
 ?.detach(this)
 ?.attach(this)
 ?.commit();
 }
 }
}
</code></pre>

blocks|key|2712660|text|现在安卓应用倾向于实现Android+Navigation组件(简化了分片管理和导航)，在这种情况下，建议采取其他方法，而不是其他建议的答案，以避免直接操作分片和与分片管理器交互。当您只需更新适配器数据时，执行“刷新”以使片段状态保持最新将不必要地破坏并重新创建视图。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|2712661|相反，您可以使用事件驱动的方法，并实现类似于事件总线的模式，消费者可以向其发布和订阅。正在更新数据的组件将负责发布与更新相关的事件，而关心更新的任何组件都可以订阅这些事件。|2712662|下面是Kotlin中的一个简单的EventBus类，它利用Kotlin语言的特性(如协程和流)来实现这个描述的模式：|2712663|import+kotlinx.coroutines.flow.MutableSharedFlow
import+kotlinx.coroutines.flow.asSharedFlow

class+EventBus+{
++++private+val+_events+=+MutableSharedFlow<AppEvent>()
++++val+events+=+_events.asSharedFlow()

++++suspend+fun+emitEvent(event:+AppEvent)+{
++++++++_events.emit(event)
++++}
}|code-block|syntax|javascript|2712664|在本例中，AppEvent是一个枚举，例如：|style|CODE|2712665|enum+class+AppEvent+{
++TODO_LIST_UPDATED
}|2712666|如果你想把数据和事件一起传递，你可以为你的AppEvent实现Kotlin+sealed+classes而不是枚举。|2712667|假设某个与您的片段无关的其他组件正在更新数据，一旦更新完成，它就会发出一个事件：|2712668|eventBus.emitEvent(AppEvent.TODO_LIST_UPDATED)|2712669|假设您使用的是MVVM架构，片段的视图模型可以在初始化时订阅事件总线：|2712670|init+{
++++viewModelScope.launch+{
++++++++eventBus.events
++++++++++++.filter+{+it+==+AppEvent.TODO_LIST_UPDATED+}
++++++++++++.collectLatest+{+
++++++++++++++++val+todosResponse+=+todoRepository.getTodos()
++++++++++++++++_todos.value+=+todosResponse.todos
++++++++++++}
++++++++}
}|2712671|一旦检索到新数据，您的片段将观察LiveData并在适配器上设置数据。|2712672|如果你没有视图模型，你可以直接在你的代码片段中做这件事，不过现在推荐使用lifecycleScope，有一个视图模型并实现MVVM架构。|2712673|需要确保的一件重要事情是，您的事件总线实例是单例实例，以便所有使用者都发布和订阅相同的总线。您可以通过使用依赖注入框架并遵循为该框架创建单例的说明来实现这一点。|2712674|您可以在blog+post+I+wrote+on+this+topic上详细了解事件总线模式。|2712675|entityMap|0|LINK|mutability|MUTABLE|url|https://developer.android.com/guide/navigation|1|https://kotlinlang.org/docs/sealed-classes.html|2|https://blog.tinaciousdesign.com/simple-event-bus-android-coroutines-flows^0|B|I|0|0|0|0|0|5|8|0|0|L|8|V|L|1|0|0|0|0|0|0|10|E|0|0|4|V|2|0^^$0|@$1|2|3|4|5|6|7|1M|8|@]|9|@$A|1N|B|1O|1|1P]]|C|$]]|$1|D|3|E|5|6|7|1Q|8|@]|9|@]|C|$]]|$1|F|3|G|5|6|7|1R|8|@]|9|@]|C|$]]|$1|H|3|I|5|J|7|1S|8|@]|9|@]|C|$K|L]]|$1|M|3|N|5|6|7|1T|8|@$A|1U|B|1V|O|P]]|9|@]|C|$]]|$1|Q|3|R|5|J|7|1W|8|@]|9|@]|C|$K|L]]|$1|S|3|T|5|6|7|1X|8|@$A|1Y|B|1Z|O|P]]|9|@$A|20|B|21|1|22]]|C|$]]|$1|U|3|V|5|6|7|23|8|@]|9|@]|C|$]]|$1|W|3|X|5|J|7|24|8|@]|9|@]|C|$K|L]]|$1|Y|3|Z|5|6|7|25|8|@]|9|@]|C|$]]|$1|10|3|11|5|J|7|26|8|@]|9|@]|C|$K|L]]|$1|12|3|13|5|6|7|27|8|@]|9|@]|C|$]]|$1|14|3|15|5|6|7|28|8|@$A|29|B|2A|O|P]]|9|@]|C|$]]|$1|16|3|17|5|6|7|2B|8|@]|9|@]|C|$]]|$1|18|3|19|5|6|7|2C|8|@]|9|@$A|2D|B|2E|1|2F]]|C|$]]|$1|1A|3|-4|5|6|7|2G|8|@]|9|@]|C|$]]]|1B|$1C|$5|1D|1E|1F|C|$1G|1H]]|1I|$5|1D|1E|1F|C|$1G|1J]]|1K|$5|1D|1E|1F|C|$1G|1L]]]]

Nowadays, Android apps tend to implement the <a href="https://developer.android.com/guide/navigation" rel="nofollow noreferrer">Android Navigation</a> component (which simplifies fragment management and navigation), in which case it is recommended to take another approach than the other suggested answers to avoid directly manipulating fragments and interacting with the fragment manager. Performing a &quot;refresh&quot; to keep your fragment state up to date unnecessarily destroys and recreates the view when all you need to do is update your adapter data.
You could instead use an event-driven approach and implement a pattern like an Event Bus, to which consumers can publish and subscribe. Your component that is updating the data would be responsible for publishing an update-related event, while any components that care about the update can subscribe to these events.
Here is a simple EventBus class in Kotlin that leverages Kotlin language features like coroutines and flows to implement this described pattern:
<pre><code>import kotlinx.coroutines.flow.MutableSharedFlow
import kotlinx.coroutines.flow.asSharedFlow

class EventBus {
 private val _events = MutableSharedFlow&lt;AppEvent&gt;()
 val events = _events.asSharedFlow()

 suspend fun emitEvent(event: AppEvent) {
 _events.emit(event)
 }
}
</code></pre>
In this case, <code>AppEvent</code> is an enum, for example:
<pre><code>enum class AppEvent {
 TODO_LIST_UPDATED
}
</code></pre>
If you'd like to pass the data alongside the event, you could implement <a href="https://kotlinlang.org/docs/sealed-classes.html" rel="nofollow noreferrer">Kotlin sealed classes</a> for your <code>AppEvent</code> instead of an enum.
Assuming some other component, unrelated to your fragment is updating the data, once it's complete it can emit an event:
<pre><code>eventBus.emitEvent(AppEvent.TODO_LIST_UPDATED)
</code></pre>
Assuming you are using MVVM architecture, your fragment's view model can subscribe to the event bus when initialized:
<pre><code>init {
 viewModelScope.launch {
 eventBus.events
 .filter { it == AppEvent.TODO_LIST_UPDATED }
 .collectLatest { 
 val todosResponse = todoRepository.getTodos()
 _todos.value = todosResponse.todos
 }
 }
}
</code></pre>
Your fragment would observe the LiveData and set the data on the adapter once the new data is retrieved.
If you do not have a view model, you can do this directly in your fragment, using <code>lifecycleScope</code> though nowadays, having a view model and implementing MVVM architecture is recommended.
One important thing to make sure of is that your event bus instance is a singleton instance so that all consumers are publishing and subscribing to the same bus. You can achieve this by using a dependency injection framework and following the directions on creating singletons for that framework.
You can read more about the event bus pattern in detail on a <a href="https://blog.tinaciousdesign.com/simple-event-bus-android-coroutines-flows" rel="nofollow noreferrer">blog post I wrote on this topic</a>.

blocks|key|2712688|text|如果您遵循了材料设计教程，则只需导航到将自动重新加载它的同一页面。不要忘记通过backstack添加"false“，因为您不必返回到前一个片段，因为它是相同的片段。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2712689|((NavigationHost)+getActivity()).navigateTo(new+MyNotesFragment(),+false);|code-block|syntax|javascript|2712690|import+androidx.fragment.app.Fragment;

public+interface+NavigationHost+{
++++void+navigateTo(Fragment+fragment,+boolean+addToBackstack);
}|2712691|import+android.os.Bundle;
import+androidx.appcompat.app.AppCompatActivity;
import+androidx.fragment.app.Fragment;
import+androidx.fragment.app.FragmentTransaction;

public+class+MainActivity+extends+AppCompatActivity+implements+NavigationHost+{

++++@Override
++++protected+void+onCreate(Bundle+savedInstanceState)+{
++++++++super.onCreate(savedInstanceState);
++++++++setContentView(R.layout.activity_main);
++++++++if+(savedInstanceState+==+null)+{
++++++++++++getSupportFragmentManager()
++++++++++++++++++++.beginTransaction()
++++++++++++++++++++.add(R.id.container,+new+LoginFragment())
++++++++++++++++++++.commit();
++++++++}
++++}

++++@Override
++++public+void+navigateTo(Fragment+fragment,+boolean+addToBackstack)+{
++++++++FragmentTransaction+transaction+=
++++++++++++++++getSupportFragmentManager()
++++++++++++++++++++++++.beginTransaction()
++++++++++++++++++++++++.replace(R.id.container,+fragment);

++++++++if+(addToBackstack)+{
++++++++++++transaction.addToBackStack(null);
++++++++}

++++++++transaction.commit();
++++}
}|2712692|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|D|7|O|8|@]|9|@]|A|$E|F]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

If you followed the Material design tutorial, you can just navigate to the same page which will automatically reload it. Don't forget to add &quot;false&quot; by backstack because you don't have to return to the previous fragment because it was the same fragment.
<pre><code>((NavigationHost) getActivity()).navigateTo(new MyNotesFragment(), false);
</code></pre>
<pre><code>import androidx.fragment.app.Fragment;

public interface NavigationHost {
 void navigateTo(Fragment fragment, boolean addToBackstack);
}
</code></pre>
<pre><code>import android.os.Bundle;
import androidx.appcompat.app.AppCompatActivity;
import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentTransaction;

public class MainActivity extends AppCompatActivity implements NavigationHost {

 @Override
 protected void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.activity_main);
 if (savedInstanceState == null) {
 getSupportFragmentManager()
 .beginTransaction()
 .add(R.id.container, new LoginFragment())
 .commit();
 }
 }

 @Override
 public void navigateTo(Fragment fragment, boolean addToBackstack) {
 FragmentTransaction transaction =
 getSupportFragmentManager()
 .beginTransaction()
 .replace(R.id.container, fragment);

 if (addToBackstack) {
 transaction.addToBackStack(null);
 }

 transaction.commit();
 }
}
</code></pre>

blocks|key|2502906|text|#我的项目是用Android+Navigation#拼接的|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2502907|MainList片段调用FilterDialog片段。在程序和用户完成过滤器对话框中的工作后，按下return按钮返回到MainList片段，并根据请求刷新它。如果你有一个Viewmodel并且能够分享日期，这很容易做到。|2502908|我先给你结尾，然后给出通向它的代码链。|2502909|*val+navController+=+findNavController()
navController.run{++popBackStack()
navigate(mViewModel.+FilterDialogReturnTarget+)}`*|code-block|syntax|javascript|2502910|这将弹出backstack并正确刷新返回片段，以反映对过滤器的更改。|2502911|++++>>>+Viewmodel:
import+androidx.lifecycle.ViewModel+…….+

class+MainActivityViewModel+:+ViewModel()+{+……+

var+FilterDialogReturnTarget:Int=0…….+


+++>>navigation+Graph

+navigation/nglist.xml
+<navigation+…….
+<fragment
+android:id="@%2Bid/nav_main_list"+……+


++++>>>MainList.kt
class+MainList+:+androidx.fragment.app.Fragment(){……

import+App.name.name.viewmodel.MainActivityViewModel
private+val+mViewModel:+MainActivityViewModel+by+activityViewModels()


private+fun+setUpListeners()+{….

binding.vemlBtnFilterOn.setOnClickListener+{…….

mViewModel.FilterDialogReturnTarget+=+R.id.nav_main_list
findNavController().navigate(R.id.action_main_list_to_FilterDialog)
}

++++>>>FilterDialog.kt
import+androidx.fragment.app.DialogFragment
import+app.name.name.MainActivityViewModel

class+ElectionsFilterDialog+:+DialogFragment(){…..
private+val+mViewModel:+MainActivityViewModel+by+activityViewModels()


private+fun+setUpListeners()+{….
binding.vemlBtnFilterOn.setOnClickListener+{…….
val+navController+=+findNavController()
navController.run{++popBackStack()
navigate(mViewModel.FilterDialogReturnTarget+)}|2502912|这对我来说很有吸引力，因为我已经有了视图模型和导航。|2502913|entityMap^0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|T|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|U|8|@]|9|@]|A|$]]|$1|F|3|G|5|H|7|V|8|@]|9|@]|A|$I|J]]|$1|K|3|L|5|6|7|W|8|@]|9|@]|A|$]]|$1|M|3|N|5|H|7|X|8|@]|9|@]|A|$I|J]]|$1|O|3|P|5|6|7|Y|8|@]|9|@]|A|$]]|$1|Q|3|-4|5|6|7|Z|8|@]|9|@]|A|$]]]|R|$]]

#My project is constructed with fragments using Android Navigation#
MainList fragment calls up FilterDialog Fragment.
After the program and the user finish there work in the Filter dialog, a return button is pushed returns to the MainList Fragment and refreshes it as requested. If you have a Viewmodel and are able to share date this is easy to do.
I give you the end first and then the chain of coding that leads up to it.
<pre><code>*val navController = findNavController()
navController.run{ popBackStack()
navigate(mViewModel. FilterDialogReturnTarget )}`*
</code></pre>
this pops the backstack and refreshes the return Fragment properly to reflect changes to the filter.
<pre><code> &gt;&gt;&gt; Viewmodel:
import androidx.lifecycle.ViewModel ……. 

class MainActivityViewModel : ViewModel() { …… 

var FilterDialogReturnTarget:Int=0……. 


 &gt;&gt;navigation Graph

 navigation/nglist.xml
 &lt;navigation …….
 &lt;fragment
 android:id=&quot;@+id/nav_main_list&quot; …… 


 &gt;&gt;&gt;MainList.kt
class MainList : androidx.fragment.app.Fragment(){……

import App.name.name.viewmodel.MainActivityViewModel
private val mViewModel: MainActivityViewModel by activityViewModels()


private fun setUpListeners() {….

binding.vemlBtnFilterOn.setOnClickListener {…….

mViewModel.FilterDialogReturnTarget = R.id.nav_main_list
findNavController().navigate(R.id.action_main_list_to_FilterDialog)
}

 &gt;&gt;&gt;FilterDialog.kt
import androidx.fragment.app.DialogFragment
import app.name.name.MainActivityViewModel

class ElectionsFilterDialog : DialogFragment(){…..
private val mViewModel: MainActivityViewModel by activityViewModels()


private fun setUpListeners() {….
binding.vemlBtnFilterOn.setOnClickListener {…….
val navController = findNavController()
navController.run{ popBackStack()
navigate(mViewModel.FilterDialogReturnTarget )}
</code></pre>
this works like a charm for me as I already had the viewmodel and navigation in place.

I have an <code>Activity</code> with a fragment container in layout.
3 different <code>Fragment</code> can be displayed in it.
These fragments contains a <code>Listview</code> which displays data with custom Adapter i made.
So each list elements is created during <code>onCreateView</code>, after i queried a database to have data.
But sometimes some data may changes in my database, so i would like to redraw/recreate it the <code>Listview</code>.
<ul>
<li>What would be the best way (i mean, the less ressources demanding) to refresh my fragment view ?</li>
<li>Is there a method to recall onCreateView manually ?</li>
</ul>

Method to refresh Fragment content when data changed ( like recall onCreateView)

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数据库

Android

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Kotlin

我在布局中有一个带有片段容器的Activity。它可以显示3种不同的Fragment。这些片段包含一个Listview，它使用我制作的自定义适配器显示数据。因此，每个列表元素都是在onCreateView期间创建的，也就是在我查询数据库以获得数据之后。但有时我的数据库中的一些数据可能会发生变化，所以我想在Listvie...

问当数据发生变化时刷新片段内容的方法(如recall onCreateView)
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