Finishing current activity from a fragment

I have a fragment in an activity that I am using as a navigation drawer. It contains buttons that when clicked start new activities (startActivity from a fragment simply calls startActivity on the current activity).

For the life of me I can't seem to figure out how I would finish the current activity after starting a new one.

I am looking to achieve something like this in the fragment:

@Override
public void onClick(View view) {
// TODO Auto-generated method stub
if (view == mButtonShows) {
Intent intent = new Intent(view.getContext(), MyNewActivity.class);
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(intent);
finish();
}
}

But it seems Fragment.class does not implement finish() (like it implements startActivity(...)).

I would like the activity backstack cleared when they launch the 2nd activity. (so pressing back from the new activity would technically drop them back to the launcher)

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最佳答案

When working with fragments, instead of using this or refering to the context, always use getActivity(). You should call

爪哇咖啡

getActivity().finish();

科特林

activity.finish()

来完成你的任务。

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其实..。

I wouldn't have the Fragment try to finish the Activity. That places too much authority on the Fragment in my opinion. Instead, I would use the guide here: http://developer.android.com/training/basics/fragments/communicating.html

让片段定义一个活动必须实现的接口。调用 Activity，然后让 Activity 决定如何处理这些信息。如果活动希望自己完成，那么它可以完成。

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正如 乔恩 · F · 汉考克所提到的，这就是片段通过建议活动关闭来“关闭”活动的方式。这使得片段具有可移植性，这就是它们的原因。如果在其他活动中使用它，则可能不希望关闭该活动。

下面的代码是一个活动和片段的片段，其中有一个保存和取消按钮。

玩家活动

public class PlayerActivity extends Activity
implements PlayerInfo.PlayerAddListener {


public void onPlayerCancel() {
// Decide if its suitable to close the activity,
//e.g. is an edit being done in one of the other fragments?
finish();
}
}

PlayerInfoFragment，它包含调用活动需要实现的接口。

public class PlayerInfoFragment extends Fragment {
private PlayerAddListener callback; // implemented in the Activity


@Override
public void onAttach(Activity activity) {
super.onAttach(activity);
callback= (PlayerAddListener) activity;
}


public interface PlayerAddListener {
public void onPlayerSave(Player p); // not shown in impl above
public void onPlayerCancel();
}


public void btnCancel(View v) {
callback.onPlayerCancel(); // the activity's implementation
}
}
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每次我用 Finish 关闭碎片，整个活动就会关闭。根据文档，只要父活动保持不变，片段就应该保持不变。

相反，我发现我可以通过使用以下语句来更改父活动的视图: SetContentView (R.layout.activity _ main) ;

这将我返回到父活动。

I hope that this helps someone else who may be looking for this.

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try to use this

是的，Fragment.class不实现 finish()

当处理片段时，不要使用这个或引用上下文，总是使用 getActivity()

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很简单。

1- just grab activity by getActivity() in the fragment

2-然后呼叫 finish();

所以只有 getActivity().finish();将完成父活动。

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您应该使用 getActivity ()方法来完成片段中的活动。

getActivity().finish();
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In Fragment use getActivity.finishAffinity()

getActivity().finishAffinity();

It will remove all the fragment which pushed by the current activity from the Stack with the Activity too...

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试试这个，不应该有任何警告..。

            Activity thisActivity = getActivity();
if (thisActivity != null) {
startActivity(new Intent(thisActivity, yourActivity.class)); // if needed
thisActivity.finish();
}
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爪哇和 Kotlin 有两个选择。然而，这两种方式的逻辑是相同的。应该在调用 完成()方法之后调用 活动。

科特林的回答,

如果您的活动不能为空，使用 答案 _ 1。但是，如果您的活动 可以是无效的，使用 答案 _ 2。

Answer_1: activity!!.finish()
Answer_2: activity?.finish()

答案是 Java,

getActivity().finish();
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这不需要断言，最新的更新片段在 android JetPack

requireActivity().finish();
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Simple solution:

activity?.finish()
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完成片段使用中的活动:

getActivity().finish();


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