MultiSelectListPreference示例

我很难findAndroid API中提供的MultiSelectListPreference的一个很好的例子。 我已经看到很多这个博客的参考,这是我想要的最终结果,我不想创build一个类,我想实现每个多select偏好。 最后,我想看到一个简单的多选对话框(我将dynamic填充值),以及对addPreferencesFromResource(R.xml.preferences);的调用addPreferencesFromResource(R.xml.preferences);

目前,我有:

 <MultiSelectListPreference android:defaultValue="" android:enabled="true" android:entries="@array/pref_default_entries" android:entryValues="@array/pref_default_values" android:key="TargetList" android:persistent="true" android:summary="@string/TargetSummary" android:title="@string/TargetTitle" /> 

当我尝试在我的Activities onCreate调用中调用addPreferencesFromResource时,出现以下错误:

 06-18 13:59:30.690: E/AndroidRuntime(6052): FATAL EXCEPTION: main 06-18 13:59:30.690: E/AndroidRuntime(6052): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.tracker/com.tracker.TrackerActivity}: android.view.InflateException: Binary XML file line #37: Error inflating class java.lang.reflect.Constructor 06-18 13:59:30.690: E/AndroidRuntime(6052): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1818) 06-18 13:59:30.690: E/AndroidRuntime(6052): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1834) 06-18 13:59:30.690: E/AndroidRuntime(6052): at android.app.ActivityThread.access$500(ActivityThread.java:122) 06-18 13:59:30.690: E/AndroidRuntime(6052): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1027) 06-18 13:59:30.690: E/AndroidRuntime(6052): at android.os.Handler.dispatchMessage(Handler.java:99) 06-18 13:59:30.690: E/AndroidRuntime(6052): at android.os.Looper.loop(Looper.java:132) 06-18 13:59:30.690: E/AndroidRuntime(6052): at android.app.ActivityThread.main(ActivityThread.java:4126) 06-18 13:59:30.690: E/AndroidRuntime(6052): at java.lang.reflect.Method.invokeNative(Native Method) 06-18 13:59:30.690: E/AndroidRuntime(6052): at java.lang.reflect.Method.invoke(Method.java:491) 06-18 13:59:30.690: E/AndroidRuntime(6052): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:844) 06-18 13:59:30.690: E/AndroidRuntime(6052): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:602) 06-18 13:59:30.690: E/AndroidRuntime(6052): at dalvik.system.NativeStart.main(Native Method) 06-18 13:59:30.690: E/AndroidRuntime(6052): Caused by: android.view.InflateException: Binary XML file line #37: Error inflating class java.lang.reflect.Constructor 06-18 13:59:30.690: E/AndroidRuntime(6052): at android.preference.GenericInflater.createItem(GenericInflater.java:397) 06-18 13:59:30.690: E/AndroidRuntime(6052): at android.preference.GenericInflater.onCreateItem(GenericInflater.java:417) 06-18 13:59:30.690: E/AndroidRuntime(6052): at android.preference.GenericInflater.createItemFromTag(GenericInflater.java:428) 06-18 13:59:30.690: E/AndroidRuntime(6052): at android.preference.GenericInflater.rInflate(GenericInflater.java:481) 06-18 13:59:30.690: E/AndroidRuntime(6052): at android.preference.GenericInflater.inflate(GenericInflater.java:326) 06-18 13:59:30.690: E/AndroidRuntime(6052): at android.preference.GenericInflater.inflate(GenericInflater.java:263) 06-18 13:59:30.690: E/AndroidRuntime(6052): at android.preference.PreferenceManager.inflateFromResource(PreferenceManager.java:269) 06-18 13:59:30.690: E/AndroidRuntime(6052): at android.preference.PreferenceActivity.addPreferencesFromResource(PreferenceActivity.java:1366) 06-18 13:59:30.690: E/AndroidRuntime(6052): at com.tracker.TrackerActivity.onCreate(TrackerActivity.java:30) 06-18 13:59:30.690: E/AndroidRuntime(6052): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1050) 06-18 13:59:30.690: E/AndroidRuntime(6052): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1782) 06-18 13:59:30.690: E/AndroidRuntime(6052): ... 11 more 06-18 13:59:30.690: E/AndroidRuntime(6052): Caused by: java.lang.reflect.InvocationTargetException 06-18 13:59:30.690: E/AndroidRuntime(6052): at java.lang.reflect.Constructor.constructNative(Native Method) 06-18 13:59:30.690: E/AndroidRuntime(6052): at java.lang.reflect.Constructor.newInstance(Constructor.java:416) 06-18 13:59:30.690: E/AndroidRuntime(6052): at android.preference.GenericInflater.createItem(GenericInflater.java:383) 06-18 13:59:30.690: E/AndroidRuntime(6052): ... 21 more 06-18 13:59:30.690: E/AndroidRuntime(6052): Caused by: java.lang.NullPointerException 06-18 13:59:30.690: E/AndroidRuntime(6052): at android.content.res.AssetManager.getResourceTextArray(AssetManager.java:215) 06-18 13:59:30.690: E/AndroidRuntime(6052): at android.content.res.Resources.getTextArray(Resources.java:435) 06-18 13:59:30.690: E/AndroidRuntime(6052): at android.content.res.TypedArray.getTextArray(TypedArray.java:628) 06-18 13:59:30.690: E/AndroidRuntime(6052): at android.preference.MultiSelectListPreference.onGetDefaultValue(MultiSelectListPreference.java:210) 06-18 13:59:30.690: E/AndroidRuntime(6052): at android.preference.Preference.<init>(Preference.java:257) 06-18 13:59:30.690: E/AndroidRuntime(6052): at android.preference.DialogPreference.<init>(DialogPreference.java:69) 06-18 13:59:30.690: E/AndroidRuntime(6052): at android.preference.DialogPreference.<init>(DialogPreference.java:90) 06-18 13:59:30.690: E/AndroidRuntime(6052): at android.preference.MultiSelectListPreference.<init>(MultiSelectListPreference.java:49) 06-18 13:59:30.690: E/AndroidRuntime(6052): ... 24 more 

我期待你的回复!

Solutions Collecting From Web of "MultiSelectListPreference示例"

Sigrist是正确的,以解决你所看到的最初的错误。 它需要提供的默认值,即使它是空的。 这帮助我,我想在RUNTIME提供价值,但不要混淆完整的实现。

请参阅此代码,了解如何在运行时提供值,而不必处理完整的实现。

 public class CalendarListPreference extends MultiSelectListPreference { ContentResolver cr; Cursor cursor; String[] projection = new String[] {CalendarContract.Calendars.NAME, CalendarContract.Calendars.CALENDAR_DISPLAY_NAME}; String selection = "(" + CalendarContract.Calendars.VISIBLE + " = ?)"; String[] selectionArgs = new String[] { "1" }; public CalendarListPreference(Context context, AttributeSet attrs) { super(context, attrs); List<CharSequence> entries = new ArrayList<CharSequence>(); List<CharSequence> entriesValues = new ArrayList<CharSequence>(); cr = context.getContentResolver(); cursor = cr.query(CalendarContract.Calendars.CONTENT_URI, projection, selection, selectionArgs, null); while (cursor.moveToNext()) { String name = cursor.getString(0); String displayName = cursor.getString(1); entries.add(name); entriesValues.add(displayName); } setEntries(entries.toArray(new CharSequence[]{})); setEntryValues(entriesValues.toArray(new CharSequence[]{})); } } 

在我的strings.xml

 <string-array name="pref_calendar_list_default"> </string-array> 

在我的preferences.xml

 <com.mynameistodd.autovolume.CalendarListPreference android:defaultValue="@array/pref_calendar_list_default" android:key="@string/pref_calendar_list_key" android:summary="@string/pref_calendar_list_summary" android:title="@string/pref_calendar_list_title" android:dependency="@string/pref_calendar_enabled_key"/> 

我知道这是一个老问题,但它帮助了我,所以这里是我的答案!

您需要指定defaultValues属性

 <MultiSelectListPreference android:dialogTitle="@string/mode_repeat" android:key="mode_repeat" android:summary="" android:title="@string/mode_repeat" android:entries="@array/weekdays" android:entryValues="@array/weekdays_values" android:defaultValue="@array/empty_array" /> 

如果你不想使用默认值,在你的strings.xml中创build一个空数组

 <string-array name="empty_array"/> 

我已经在11级以前的API中为运行Android的设备创build了MultiSelectListPreference。

  • 支持ChangeListener接收选定值的列表。
  • 支持自动设置摘要。
  • 附加示例

https://gist.github.com/cardil/4754571

 package pl.wavesoftware.widget; import java.util.ArrayList; import java.util.Arrays; import java.util.Iterator; import java.util.List; import android.app.AlertDialog.Builder; import android.content.Context; import android.content.DialogInterface; import android.content.DialogInterface.OnMultiChoiceClickListener; import android.content.res.TypedArray; import android.preference.ListPreference; import android.util.AttributeSet; public class MultiSelectListPreference extends ListPreference { private String separator; private static final String DEFAULT_SEPARATOR = "\u0001\u0007\u001D\u0007\u0001"; private boolean[] entryChecked; public MultiSelectListPreference(Context context, AttributeSet attributeSet) { super(context, attributeSet); entryChecked = new boolean[getEntries().length]; separator = DEFAULT_SEPARATOR; } public MultiSelectListPreference(Context context) { this(context, null); } @Override protected void onPrepareDialogBuilder(Builder builder) { CharSequence[] entries = getEntries(); CharSequence[] entryValues = getEntryValues(); if (entries == null || entryValues == null || entries.length != entryValues.length) { throw new IllegalStateException( "MultiSelectListPreference requires an entries array and an entryValues " + "array which are both the same length"); } restoreCheckedEntries(); OnMultiChoiceClickListener listener = new DialogInterface.OnMultiChoiceClickListener() { public void onClick(DialogInterface dialog, int which, boolean val) { entryChecked[which] = val; } }; builder.setMultiChoiceItems(entries, entryChecked, listener); } private CharSequence[] unpack(CharSequence val) { if (val == null || "".equals(val)) { return new CharSequence[0]; } else { return ((String) val).split(separator); } } /** * Gets the entries values that are selected * * @return the selected entries values */ public CharSequence[] getCheckedValues() { return unpack(getValue()); } private void restoreCheckedEntries() { CharSequence[] entryValues = getEntryValues(); // Explode the string read in sharedpreferences CharSequence[] vals = unpack(getValue()); if (vals != null) { List<CharSequence> valuesList = Arrays.asList(vals); for (int i = 0; i < entryValues.length; i++) { CharSequence entry = entryValues[i]; entryChecked[i] = valuesList.contains(entry); } } } @Override protected void onDialogClosed(boolean positiveResult) { List<CharSequence> values = new ArrayList<CharSequence>(); CharSequence[] entryValues = getEntryValues(); if (positiveResult && entryValues != null) { for (int i = 0; i < entryValues.length; i++) { if (entryChecked[i] == true) { String val = (String) entryValues[i]; values.add(val); } } String value = join(values, separator); setSummary(prepareSummary(values)); setValueAndEvent(value); } } private void setValueAndEvent(String value) { if (callChangeListener(unpack(value))) { setValue(value); } } private CharSequence prepareSummary(List<CharSequence> joined) { List<String> titles = new ArrayList<String>(); CharSequence[] entryTitle = getEntries(); CharSequence[] entryValues = getEntryValues(); int ix = 0; for (CharSequence value : entryValues) { if (joined.contains(value)) { titles.add((String) entryTitle[ix]); } ix += 1; } return join(titles, ", "); } @Override protected Object onGetDefaultValue(TypedArray typedArray, int index) { return typedArray.getTextArray(index); } @Override protected void onSetInitialValue(boolean restoreValue, Object rawDefaultValue) { String value = null; CharSequence[] defaultValue; if (rawDefaultValue == null) { defaultValue = new CharSequence[0]; } else { defaultValue = (CharSequence[]) rawDefaultValue; } List<CharSequence> joined = Arrays.asList(defaultValue); String joinedDefaultValue = join(joined, separator); if (restoreValue) { value = getPersistedString(joinedDefaultValue); } else { value = joinedDefaultValue; } setSummary(prepareSummary(Arrays.asList(unpack(value)))); setValueAndEvent(value); } /** * Joins array of object to single string by separator * * Credits to kurellajunior on this post * http://snippets.dzone.com/posts/show/91 * * @param iterable * any kind of iterable ex.: <code>["a", "b", "c"]</code> * @param separator * separetes entries ex.: <code>","</code> * @return joined string ex.: <code>"a,b,c"</code> */ protected static String join(Iterable<?> iterable, String separator) { Iterator<?> oIter; if (iterable == null || (!(oIter = iterable.iterator()).hasNext())) return ""; StringBuilder oBuilder = new StringBuilder(String.valueOf(oIter.next())); while (oIter.hasNext()) oBuilder.append(separator).append(oIter.next()); return oBuilder.toString(); } }