我有一个OnPreferenceClickListener应该Preference从.preference_to_removePreferenceScreen
问题是，当我的解决方案preference_to_remove不在PreferenceScreen嵌套屏幕内但不起作用时，当它位于嵌套屏幕内并且屏幕方向发生变化时，我的解决方案才有效。在屏幕方向更改之前，嵌套屏幕也可以按预期工作。
下面的代码包含两个版本，一个是扁平的非嵌套版本，一个PreferenceScreen是破碎的嵌套版本PreferenceScreen。
屏幕方向更改后嵌套版本无法删除Preferencewith 键的原因是什么？除了只使用 flat并以伪孩子的身份开始新preference_to_remove的工作之外，还有什么解决方案？PreferenceScreensIntentsPreferenceScreens
PS：我正在使用PreferenceActivityFroYo 兼容性。
如何使用 Test-App 重现
打开应用程序→单击平面按钮→单击preference_to_click应删除preference_to_remove的 . → 方向更改 → 单击preference_to_click以再次删除preference_to_remove。偏好已删除？成功！
打开 App → 点击 Subscreen-Button → 点击 Test → 现在重复第一次测试的步骤，但这一次preference_to_remove在方向改变后将无法移除。
pref_flat.xml
<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android" >
<Preference
android:key="preference_to_click"
android:persistent="false"
android:title="preference_to_click" />
<Preference
android:key="preference_to_remove"
android:title="preference_to_remove" />
</PreferenceScreen>
pref_subscreen.xml（嵌套的 PreferenceScreen）
<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android" >
<PreferenceScreen
android:key="subscreen"
android:persistent="false"
android:title="Test" >
<Preference
android:key="preference_to_click"
android:persistent="false"
android:title="preference_to_click" />
<Preference
android:key="preference_to_remove"
android:title="preference_to_remove" />
</PreferenceScreen>
</PreferenceScreen>
PrefFlatActivity.java 和 PrefSubscreenActivity.java 的区别
1c1
< public class PrefFlatActivity extends PreferenceActivity {
---
> public class PrefSubscreenActivity extends PreferenceActivity {
5,6c5,7
< public static final String PREFERENCE_TO_CLICK = "preference_to_click";
< public static final String PREFERENCE_TO_REMOVE = "preference_to_remove";
---
> private static final String PREFERENCE_TO_CLICK = PrefFlatActivity.PREFERENCE_TO_CLICK;
> private static final String PREFERENCE_TO_REMOVE = PrefFlatActivity.PREFERENCE_TO_REMOVE;
> private static final String PREFERENCE_SUBSCREEN = "subscreen";
15c16
< addPreferencesFromResource(R.xml.pref_flat);
---
> addPreferencesFromResource(R.xml.pref_subscreen);
28c29
< PreferenceScreen screen = getPreferenceScreen();
---
> PreferenceScreen screen = (PreferenceScreen) findPreference(PREFERENCE_SUBSCREEN);
PrefFlatActivity.java（工作）
/**
* Works as expected. Clicking toggles the "visibility" of the PREFERENCE_TO_REMOVE Preference.
*/
public class PrefFlatActivity extends PreferenceActivity {
/**
* Preference keys.
*/
public static final String PREFERENCE_TO_CLICK = "preference_to_click";
public static final String PREFERENCE_TO_REMOVE = "preference_to_remove";
private final String PREF_NAME = getClass().getName() + ".pref";
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
getPreferenceManager().setSharedPreferencesName(PREF_NAME);
addPreferencesFromResource(R.xml.pref_flat);
findPreference(PREFERENCE_TO_CLICK)
.setOnPreferenceClickListener(new OnFlatClickListener());
}
/**
* Removes or adds Preference with key PREFERENCE_TO_REMOVE when clicked.
*/
private class OnFlatClickListener implements OnPreferenceClickListener {
private Preference mRescuedPreference;
public boolean onPreferenceClick(Preference preference) {
PreferenceScreen screen = getPreferenceScreen();
Preference prefToRemove = screen.findPreference(PREFERENCE_TO_REMOVE);
Log.d("test", "Found PREFERENCE_TO_REMOVE: " + (prefToRemove != null));
if (prefToRemove != null) {
screen.removePreference(prefToRemove);
mRescuedPreference = prefToRemove; // Rescue reference to re-add it later.
}
else {
screen.addPreference(mRescuedPreference);
}
return true;
}
}
}
PrefSubscreenActivity.java（嵌套，方向改变后损坏）
/**
* Broken after orientation change. Clicking does not remove/add PREFERENCE_TO_REMOVE.
*/
public class PrefSubscreenActivity extends PreferenceActivity {
/**
* Preference keys.
*/
private static final String PREFERENCE_TO_CLICK = PrefFlatActivity.PREFERENCE_TO_CLICK;
private static final String PREFERENCE_TO_REMOVE = PrefFlatActivity.PREFERENCE_TO_REMOVE;
private static final String PREFERENCE_SUBSCREEN = "subscreen";
private final String PREF_NAME = getClass().getName() + ".pref";
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
getPreferenceManager().setSharedPreferencesName(PREF_NAME);
addPreferencesFromResource(R.xml.pref_subscreen);
findPreference(PREFERENCE_TO_CLICK)
.setOnPreferenceClickListener(new OnFlatClickListener());
}
/**
* Removes or adds Preference with key PREFERENCE_TO_REMOVE when clicked.
*/
private class OnFlatClickListener implements OnPreferenceClickListener {
private Preference mRescuedPreference;
public boolean onPreferenceClick(Preference preference) {
PreferenceScreen screen = (PreferenceScreen) findPreference(PREFERENCE_SUBSCREEN);
Preference prefToRemove = screen.findPreference(PREFERENCE_TO_REMOVE);
Log.d("test", "Found PREFERENCE_TO_REMOVE: " + (prefToRemove != null));
if (prefToRemove != null) {
screen.removePreference(prefToRemove);
mRescuedPreference = prefToRemove; // Rescue reference to re-add it later.
}
else {
screen.addPreference(mRescuedPreference);
}
return true;
}
}
}