Question

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。

Answer 1

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);
    }



}

CustomListPreference不保存任何选项而不设置默认值

1 个答案: