从sameple custom row in a listPreference?我尝试创建自己的自定义列表首选项，但没有任何内容被保存或者没有填充旧索引。
public class FontSizePreference extends ListPreference {
private CustomListPreferenceAdapter customListPreferenceAdapter = null;
private Context mContext;
private LayoutInflater mInflater;
// private CharSequence[] entries;
// private CharSequence[] entryValues;
private ArrayList<RadioButton> rButtonList;
private SharedPreferences prefs;
private SharedPreferences.Editor editor;
private static final String TAG = FontSizePreference.class.getSimpleName();
private String font_size = "";
public FontSizePreference(Context context, AttributeSet attrs) {
super(context, attrs);
mContext = context;
mInflater = LayoutInflater.from(context);
rButtonList = new ArrayList<RadioButton>();
prefs = PreferenceManager.getDefaultSharedPreferences(mContext);
editor = prefs.edit();
}
@Override
protected void onPrepareDialogBuilder(Builder builder) {
font_size = prefs.getString(KEY_FONT_SIZE, "18");
if (getEntries() == null || getEntryValues() == null
|| getEntries().length != getEntryValues().length) {
throw new IllegalStateException(
"ListPreference requires an entries array and an entryValues array which are both the same length");
}
customListPreferenceAdapter = new CustomListPreferenceAdapter(mContext, getEntries(),
getEntryValues());
builder.setAdapter(customListPreferenceAdapter, new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
}
});
super.onPrepareDialogBuilder(builder);
}
private class CustomListPreferenceAdapter extends BaseAdapter {
private CharSequence[] entries;
private CharSequence[] entryValues;
public CustomListPreferenceAdapter(Context mContext, CharSequence[] entries,
CharSequence[] entryValues) {
this.entries = entries;
this.entryValues = entryValues;
}
public int getCount() {
return entries.length;
}
public Object getItem(int position) {
return entries[position];
}
public long getItemId(int position) {
return position;
}
public View getView(final int position, View convertView, ViewGroup parent) {
CustomHolder holder = null;
View row = convertView;
if (row == null) {
row = mInflater.inflate(R.layout.fontsize_layout, parent, false);
}
boolean flag = false;
for (CharSequence entry : entryValues) {
if (entry.toString().equals(font_size)) {
flag = true;
}
}
holder = new CustomHolder(row, position, font_size, flag);
row.setTag(holder);
row.setClickable(false);
row.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
for (RadioButton rb : rButtonList) {
Log.d(TAG, "current row listener : " + rb.getId() + " : : : " + position);
if (rb.getId() != position)
rb.setChecked(false);
else
rb.setChecked(true);
}
int index = position;
String value = (String)entryValues[index];
editor.putString(KEY_FONT_SIZE, value).commit();
getDialog().dismiss();
}
});
return row;
}
class CustomHolder {
private TextView text = null;
private RadioButton rButton = null;
CustomHolder(final View row, final int position, String prefValue, boolean checked) {
Log.d(TAG, "current position is : " + position);
text = (TextView)row.findViewById(R.id.fontSizeTitle);
text.setText(entries[position]);
text.setTextSize(Float.valueOf(entryValues[position].toString()));
rButton = (RadioButton)row.findViewById(R.id.fontSizeState);
int newIndex = Arrays.asList(entryValues).indexOf(prefValue);
// rButton.setId(newIndex);
if (position != newIndex)
rButton.setChecked(false);
rButtonList.add(rButton);
rButton.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
@Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
// TODO Auto-generated method stub
if (isChecked) {
for (RadioButton rb : rButtonList) {
if (rb != buttonView)
rb.setChecked(false);
else {
rb.setChecked(true);
}
}
}
int index = buttonView.getId();
String value = (String)entryValues[position];
editor.putString(KEY_FONT_SIZE, value).commit();
getDialog().dismiss();
}
});
}
}
}
每次运行此示例时，它都会生成35个单选按钮实例，并且不会在视图中显示上一个选定按钮或当前选定按钮。请帮我解决这个问题。 以下是数组，布局和首选调用的xml代码
<string-array name="font_size_options">
<item>Larger</item>
<item>Large</item>
<item>Medium</item>
<item>Small</item>
<item>Smallest</item>
</string-array>
<string-array name="font_size_values">
<item>26</item>
<item>20</item>
<item>18</item>
<item>14</item>
<item>10</item>
</string-array>
layout xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:clickable="true"
android:orientation="horizontal"
android:padding="5dp" >
<TextView
android:id="@+id/fontSizeTitle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:layout_weight="1"
/>
<RadioButton
android:id="@+id/fontSizeState"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center_vertical"
android:layout_weight="0" />
</LinearLayout>
，首选是：
<com.example.samplepreference.FontSizePreference
android:key="semc_pref_key_font_size"
android:entries="@array/font_size_options"
android:entryValues="@array/font_size_values"
android:title="@string/font_size_title" />
同时设置按钮(rButton.setId(newIndex))始终返回nullpointer。
答案 0 :(得分：0)
我用另一个例子中的另一个方法解决了这个问题（选择的想法）忘记了该解决方案的链接，但是一旦找到它就会更新它。
public class FontSizePreference extends ListPreference {
private Context mContext;
private CharSequence[] entries = null;
private CharSequence[] entryValues = null;
private SharedPreferences prefs;
private SharedPreferences.Editor editor;
private static final String TAG = FontSizePreference.class.getSimpleName();
private String font_size = "";
public FontSizePreference(Context context, AttributeSet attrs) {
super(context, attrs);
mContext = context;
prefs = PreferenceManager.getDefaultSharedPreferences(mContext);
editor = prefs.edit();
entries = getEntries();
entryValues = getEntryValues();
}
@Override
protected Object onGetDefaultValue(TypedArray a, int index) {
return super.onGetDefaultValue(a, 2);
}
@Override
protected void onPrepareDialogBuilder(Builder builder) {
String choosenIndex = getPersistedString("18");
choosenIndex = (!getValue().equals(choosenIndex)) ? choosenIndex : getValue();
ListAdapter adapter = new FontSizeListAdapter(getContext(),
R.layout.fontsize_layout, entries, entryValues,
Arrays.asList(entryValues).indexOf(choosenIndex) ,this);
builder.setAdapter(adapter, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface arg0, int arg1) {
}
});
super.onPrepareDialogBuilder(builder);
}
class CustomListAdapter implements ListAdapter {
private int selectedIndex = 0;
public CustomListAdapter(Context context, int customFontLayout,
CharSequence[] entries, CharSequence[] entryValues,
int selectedValue) {
this.selectedIndex = selectedValue;
}
@Override
public int getCount() {
return entries.length;
}
@Override
public Object getItem(int index) {
return entryValues[index];
}
@Override
public long getItemId(int index) {
return index;
}
@Override
public int getItemViewType(int index) {
return index;
}
@Override
public View getView(final int index, View anotherView, ViewGroup parent) {
View row = anotherView;
if (row == null) {
row = LayoutInflater.from(getContext()).inflate(
R.layout.fontsize_layout, parent, false);
}
TextView txtView = (TextView) row.findViewById(R.id.fontSizeTitle);
RadioButton buttonView = (RadioButton) row
.findViewById(R.id.fontSizeState);
row.setId(Integer.valueOf(entryValues[index].toString()));
txtView.setText(entries[index]);
if (index == selectedIndex) {
buttonView.setChecked(true);
}
txtView.setTextSize(Float.valueOf((String) entryValues[index]));
row.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
persistString(String.valueOf(v.getId()));
getDialog().dismiss();
}
});
buttonView.setOnCheckedChangeListener(
new CompoundButton.OnCheckedChangeListener() {
@Override
public void onCheckedChanged(CompoundButton buttonView,
boolean isChecked) {
if (isChecked) {
buttonView.setId(index);
persistString(
String.valueOf(entryValues[buttonView.getId()]));
getDialog().dismiss();
}
}
});
return row;
}
@Override
public int getViewTypeCount() {
// TODO Auto-generated method stub
return entryValues.length;
}
@Override
public boolean hasStableIds() {
// TODO Auto-generated method stub
return false;
}
@Override
public boolean isEmpty() {
// TODO Auto-generated method stub
return false;
}
@Override
public void registerDataSetObserver(DataSetObserver arg0) {
// TODO Auto-generated method stub
}
@Override
public void unregisterDataSetObserver(DataSetObserver arg0) {
// TODO Auto-generated method stub
}
@Override
public boolean areAllItemsEnabled() {
// TODO Auto-generated method stub
return false;
}
@Override
public boolean isEnabled(int arg0) {
// TODO Auto-generated method stub
return false;
}
}
@Override
protected String getPersistedString(String defaultReturnValue) {
return super.getPersistedString(defaultReturnValue);
}
@Override
protected void onSetInitialValue(boolean restoreValue, Object defaultValue) {
if (!restoreValue) {
super.onSetInitialValue(restoreValue,"18");
} else
super.onSetInitialValue(restoreValue, defaultValue);
}
public boolean persistString (String value) {
return super.persistString(value);
}
}