在 PreferenceFragmentCompat

如何解决在 PreferenceFragmentCompat

我想要实现的是拥有一个列表，其中包含对 Preference 打开的所有对话框的引用（可以是 EditTextPreference、ListPreference ...）。然后，当设备屏幕被停用时，我希望能够关闭 (.dismiss()) 所有打开的对话框。

这是 PreferenceFragmentCompat 的示例布局文件：

<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen 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">

<PreferenceCategory
    android:layout_marginTop="0dp"
    android:gravity="top"
    android:key="settings_example_category">

    <!--
    <EditTextPreference
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:key="settings_example_text"
        android:selectAllOnFocus="true"
        android:singleLine="true"
        android:title="@string/settings_example_title"
        app:useSimpleSummaryProvider="true" />
    -->
    <Preference
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:key="settings_example_text"
        android:selectAllOnFocus="true"
        android:singleLine="true"
        android:title="@string/settings_example_title"
        app:useSimpleSummaryProvider="true" />

    <ListPreference
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:defaultValue="15"
        android:dialogTitle="@string/location_update_time"
        android:entries="@array/location_update_time_interval_entries"
        android:entryValues="@array/location_update_time_interval_entry_values"
        android:key="settings_connection_location_update_time"
        android:title="@string/location_update_time"
        app:useSimpleSummaryProvider="true" />
</PreferenceCategory>

我设法通过将其更改为 Preference 并创建 Dialog 并在我的 ExampleSettingsFragment.kt 中像这样处理保存自己来使其为 EditTextPreference 工作（请参阅 initPreferenceHelper() 函数）：

class ExampleSettingsFragment : PreferenceFragmentCompat(),Preference.OnPreferenceClickListener,SharedPreferences.OnSharedPreferencechangelistener {

private var sharedPref: SharedPreferences? = null

[...]

// region Helper methods

/**
 * This function can init a Preference. [preferenceKey] must be the android:key
 * this setting will be saved under. The defaultvalue is the default value the setting is set to,* if it is not explicit set by the user. Use "" if there is no default for this setting necessary.
 */
private fun initPreferenceHelper(preferenceKey : String,defaultValue : String) {
    Timber.d("initPreferenceHelper(): $preferenceKey initialized!")
    val preference = findPreference<Preference>(preferenceKey)!!
    sharedPref = PreferenceManager.getDefaultSharedPreferences(requireActivity())

    val editText = EditText(context)
    editText.setText(sharedPref!!.getString(GlobalConstants.CONNECTION_SETTINGS_MEDICAL_DEVICE_ID,defaultValue),TextView.BufferType.EDITABLE)
    val dialog = AlertDialog.Builder(requireContext())
        .setTitle(preference.title)
        .setView(editText)
        .setPositiveButton(getString(R.string.ok),DialogInterface.OnClickListener { dialog,which ->
            if (which.equals(DialogInterface.BUTTON_POSITIVE)) {
                //save
                val userinput : String = editText.text.toString()
                sharedPref = PreferenceManager.getDefaultSharedPreferences(requireActivity())
                sharedPref!!.edit().putString(preferenceKey,userinput).apply()
                if(userinput.isNotEmpty()) {
                    preference.summary = userinput
                } else {
                    preference.summary = getString(R.string.not_set_summary)
                }
            }
            dialog.dismiss()
        })
        .setNegativeButton(getString(R.string.cancel),which ->
            dialog.dismiss()
        })
        .setCancelable(true).create()
//in the next line we register this dialog to bis dismissable later
    SettingsAlertDialogHelper.register(dialog)

    val value = sharedPref!!.getString(preferenceKey,defaultValue)
    if (value.isNullOrEmpty()) {
        preference.summary = getString(R.string.not_set_summary)
    } else {
        preference.summary = value
    }

    preference.onPreferenceClickListener = Preference.OnPreferenceClickListener {
        Timber.d("$preferenceKey clicked!")
        dialog.show()
        return@OnPreferenceClickListener true
    }
}

private fun initializeSettings() {
    initPreferenceHelper("settings_example_text","")
}
// endregion
}

我会跟踪所有对话框，并且可以使用这个助手类成功关闭它们：

class SettingsAlertDialogHelper {
    companion object {
        private var dialogs : MutableList<AlertDialog> = mutablelistof()

        /**
        * please register all [alertDialog]s used in Settings with this
        * function. Then they can be properly dismissed.
        */
        public fun register(alertDialog: AlertDialog) {
            dialogs.add(alertDialog)
            Timber.d("{register()} all currently registered Dialogs: ${dialogs.toString()}")
        }

        [...]

        /**
        * This function dismisses all registered and open dialogs and should be called each time the admin rights are gone
        */
        public fun dismissAllOpenDialogs() {
            val open = dialogs.filter { it.isShowing }
            open.forEach {
                it.dismiss()
            }
        }
    }
}

我现在遇到的问题是我不知道如何为所有不是 EditTextPreference 的首选项执行此操作。例如，您可以在第一个代码片段中看到的 ListPreference。

由于所有带有像 EditTextPreference 或 ListPreference 这样的对话框的 Preferences 似乎以某种方式从 DialogPreference 派生，它在内部似乎也使用 PreferenceFragmentCompat 我想知道是否有可能以某种方式迭代像 ExampleSettingsFragment 这样的 PreferenceFragmentCompat。 kt 以获取对 Preferences 使用的所有 Dialogs 的引用，或者能够以其他方式关闭它们。