【发布时间】：2017-02-08 10:28:17
【问题描述】：
我正在开发的应用程序将在平板电脑上运行，该平板电脑将被放置在“笼子”内以防止用户将其移除。 这个“笼子”将重新创建一个 Kiosk 模式；带有返回和主页按钮的 android 按钮栏将不会被用户物理访问。
在主要活动和片段中，我通过在某些按钮的 OnClickListener 中调用 onBackPressed() 设法“返回”。
现在的问题是我必须添加一个设置活动，这种活动不使用普通布局，而是使用 PreferenceScreen。
如果我可以在布局中显示的唯一内容是首选项，我不知道如何操作 onBackPressed()。
我尝试添加一个名为 GoBack 的 switchpreference 并创建一个持续刷新的处理程序并检查 GoBack 首选项是否为 True，在这种情况下，我会将其设置为 false 并触发 onBackPressed();但它不起作用，Go Back 没有改变，应用程序崩溃了，我无法让它工作。
这是 SettingActivity 代码（android studio 之一）
public class SettingsActivity extends AppCompatPreferenceActivity {
private static Preference.OnPreferenceChangeListener sBindPreferenceSummaryToValueListener = new Preference.OnPreferenceChangeListener() {
@Override
public boolean onPreferenceChange(Preference preference, Object value) {
String stringValue = value.toString();
if (preference instanceof ListPreference) {
// For list preferences, look up the correct display value in
// the preference's 'entries' list.
ListPreference listPreference = (ListPreference) preference;
int index = listPreference.findIndexOfValue(stringValue);
// Set the summary to reflect the new value.
preference.setSummary(
index >= 0
? listPreference.getEntries()[index]
: null);
} else if (preference instanceof RingtonePreference) {
// For ringtone preferences, look up the correct display value
// using RingtoneManager.
if (TextUtils.isEmpty(stringValue)) {
// Empty values correspond to 'silent' (no ringtone).
preference.setSummary(R.string.pref_ringtone_silent);
} else {
Ringtone ringtone = RingtoneManager.getRingtone(
preference.getContext(), Uri.parse(stringValue));
if (ringtone == null) {
// Clear the summary if there was a lookup error.
preference.setSummary(null);
} else {
// Set the summary to reflect the new ringtone display
// name.
String name = ringtone.getTitle(preference.getContext());
preference.setSummary(name);
}
}
} else {
// For all other preferences, set the summary to the value's
// simple string representation.
preference.setSummary(stringValue);
}
return true;
}
};
/**
* Helper method to determine if the device has an extra-large screen. For
* example, 10" tablets are extra-large.
*/
private static boolean isXLargeTablet(Context context) {
return (context.getResources().getConfiguration().screenLayout
& Configuration.SCREENLAYOUT_SIZE_MASK) >= Configuration.SCREENLAYOUT_SIZE_XLARGE;
}
/**
* Binds a preference's summary to its value. More specifically, when the
* preference's value is changed, its summary (line of text below the
* preference title) is updated to reflect the value. The summary is also
* immediately updated upon calling this method. The exact display format is
* dependent on the type of preference.
*
* @see #sBindPreferenceSummaryToValueListener
*/
private static void bindPreferenceSummaryToValue(Preference preference) {
// Set the listener to watch for value changes.
preference.setOnPreferenceChangeListener(sBindPreferenceSummaryToValueListener);
// Trigger the listener immediately with the preference's
// current value.
try {
sBindPreferenceSummaryToValueListener.onPreferenceChange(preference,
PreferenceManager
.getDefaultSharedPreferences(preference.getContext())
.getString(preference.getKey(), ""));
}
catch (Exception e)
{
try {
sBindPreferenceSummaryToValueListener.onPreferenceChange(preference,
PreferenceManager
.getDefaultSharedPreferences(preference.getContext())
.getBoolean(preference.getKey(),false));
}
catch (Exception ex)
{
Log.e("Impostazioni","Impossibile eseguire Sett.Binding di "+preference.getKey());
}
}
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setupActionBar();
}
/**
* Set up the {@link android.app.ActionBar}, if the API is available.
*/
private void setupActionBar() {
ActionBar actionBar = getSupportActionBar();
if (actionBar != null) {
// Show the Up button in the action bar.
actionBar.setDisplayHomeAsUpEnabled(true);
}
}
@Override
public boolean onMenuItemSelected(int featureId, MenuItem item) {
int id = item.getItemId();
if (id == android.R.id.home) {
if (!super.onMenuItemSelected(featureId, item)) {
NavUtils.navigateUpFromSameTask(this);
}
return true;
}
return super.onMenuItemSelected(featureId, item);
}
/**
* {@inheritDoc}
*/
@Override
public boolean onIsMultiPane() {
return isXLargeTablet(this);
}
/**
* {@inheritDoc}
*/
@Override
@TargetApi(Build.VERSION_CODES.HONEYCOMB)
public void onBuildHeaders(List<Header> target) {
loadHeadersFromResource(R.xml.pref_headers, target);
}
/**
* This method stops fragment injection in malicious applications.
* Make sure to deny any unknown fragments here.
*/
protected boolean isValidFragment(String fragmentName) {
return PreferenceFragment.class.getName().equals(fragmentName)
|| GeneralPreferenceFragment.class.getName().equals(fragmentName)
|| DataSyncPreferenceFragment.class.getName().equals(fragmentName)
|| NotificationPreferenceFragment.class.getName().equals(fragmentName);
}
/**
* This fragment shows general preferences only. It is used when the
* activity is showing a two-pane settings UI.
*/
@TargetApi(Build.VERSION_CODES.HONEYCOMB)
public static class GeneralPreferenceFragment extends PreferenceFragment {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
addPreferencesFromResource(R.xml.pref_general);
setHasOptionsMenu(true);
// Bind the summaries of EditText/List/Dialog/Ringtone preferences
// to their values. When their values change, their summaries are
// updated to reflect the new value, per the Android Design
// guidelines.
bindPreferenceSummaryToValue(findPreference("PassWordImpostazioni"));
//bindPreferenceSummaryToValue(findPreference("example_list"));
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
if (id == android.R.id.home) {
startActivity(new Intent(getActivity(), SettingsActivity.class));
return true;
}
return super.onOptionsItemSelected(item);
}
}
/**
* This fragment shows notification preferences only. It is used when the
* activity is showing a two-pane settings UI.
*/
@TargetApi(Build.VERSION_CODES.HONEYCOMB)
public static class NotificationPreferenceFragment extends PreferenceFragment {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
addPreferencesFromResource(R.xml.pref_notification);
setHasOptionsMenu(true);
// Bind the summaries of EditText/List/Dialog/Ringtone preferences
// to their values. When their values change, their summaries are
// updated to reflect the new value, per the Android Design
// guidelines.
/*bindPreferenceSummaryToValue(findPreference("LedBattutaPorta"));
bindPreferenceSummaryToValue(findPreference("SpoilerPosteriore"));
bindPreferenceSummaryToValue(findPreference("LuciBianche"));
bindPreferenceSummaryToValue(findPreference("Scalino"));
bindPreferenceSummaryToValue(findPreference("Webasto"));
bindPreferenceSummaryToValue(findPreference("Stufa220V"));*/
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
if (id == android.R.id.home) {
startActivity(new Intent(getActivity(), SettingsActivity.class));
return true;
}
return super.onOptionsItemSelected(item);
}
}
/**
* This fragment shows data and sync preferences only. It is used when the
* activity is showing a two-pane settings UI.
*/
@TargetApi(Build.VERSION_CODES.HONEYCOMB)
public static class DataSyncPreferenceFragment extends PreferenceFragment {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
addPreferencesFromResource(R.xml.pref_data_sync);
setHasOptionsMenu(true);
// Bind the summaries of EditText/List/Dialog/Ringtone preferences
// to their values. When their values change, their summaries are
// updated to reflect the new value, per the Android Design
// guidelines.
bindPreferenceSummaryToValue(findPreference("sync_frequency"));
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
if (id == android.R.id.home) {
startActivity(new Intent(getActivity(), SettingsActivity.class));
return true;
}
return super.onOptionsItemSelected(item);
}
}
}
这是 PreferenceScreen XML
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">
<PreferenceCategory
android:title="OPT. Luci"
android:key="OptLuci">
<SwitchPreference
android:defaultValue="false"
android:key="LedBattutaPorta"
android:title="Pulsante Disabilitazione Led Battuta Porta" />
<SwitchPreference
android:defaultValue="false"
android:key="SpoilerPosteriore"
android:title="Pulsante Disabilitazione Spoiler Posteriore" />
<SwitchPreference
android:defaultValue="false"
android:key="LuciBianche"
android:title="Pulsante Disabilitazione Luci Bianche" />
</PreferenceCategory>
<PreferenceCategory
android:title="OPT. Servizi"
android:key="OptServizi">
<SwitchPreference
android:defaultValue="false"
android:key="Scalino"
android:title="Pulsante Disabilitazione Scalino" />
</PreferenceCategory>
<PreferenceCategory
android:title="OPT. Clima"
android:key="OptClima">
<SwitchPreference
android:defaultValue="false"
android:key="Webasto"
android:title="Webasto" />
<SwitchPreference
android:defaultValue="false"
android:key="Stufa220V"
android:title="Stufa 220V" />
</PreferenceCategory>
<PreferenceCategory
android:title="OPT. Vano Sanitario"
android:key="OptVanoSanitario">
<SwitchPreference
android:defaultValue="false"
android:key="Bombola1"
android:title="Presenza Bombola 1" />
<SwitchPreference
android:defaultValue="false"
android:key="Bombola2"
android:title="Presenza Bombola 2" />
</PreferenceCategory>
【问题讨论】：
-
您是否尝试过创建自定义首选项？
-
您的设计是否允许您使用工具栏？还是操作栏？
-
我没有经验和时间来创建自定义偏好活动，这就是为什么我要对 android studio one 进行一些修改。
-
主要活动被固定和全屏，我没有任何操作栏或工具栏。当我进入设置活动时，它不再固定，但实际上我没有任何工具栏或操作栏
标签： android sharedpreferences android-settings