onBackPressed() 在 Fragment 中不起作用

Question

我想当我回来时它完全转到手机的主页，但onBackPressed()不起作用。顺便说一句，我的页面是一个片段。

Answer 1

在您的片段中使用getActivity().onBackPressed();它将执行onBackPressed()您的父活动

更准确地说

Activity activity = getActivity();

    if (activity != null) {

        activity.onBackPressed();}

编辑：用于requireActivity()避免空指针

requireActivity().onBackPressed();

Answer 2

onBackPressed 回调由您的父活动处理。因此您可以覆盖父活动的回调

XyzActivity.java:

@Override

public void onBackPressed() {

    handleBackPress();

}

public void handleBackPress() {

    Fragment visibleFragment = getSupportFragmentManager().findFragmentById(R.id.fragmentFrameLayout);

    if (visibleFragment == null) {

        return;

    }else if (visibleFragment instanceof PreviewFragment) {

        CommonFunctions.showDialogActionable(this, "Confirm", "Are you sure you want to exit?",

            "Yes", (dialogInterface, i) -> {

                finish();

            }, "No", null, "", null, true);

        return;

    }else

        finish();

    super.onBackPressed();

}