listPreference中的自定义行？

Question

我试图创建一个ListPreference但不知何故禁用其中一个项目.有点像灰色或其他东西,没有能力选择它.这将是一个即将推出的功能,我希望它在列表中是不可选择的.

我已经创建了一个自定义ListPreference类,并在该类中自定义适配器,希望使用适配器来创建我想要的.

代码工作,它设置适配器,但没有调用任何适配器函数.我在方法上设置断点,例如getCount()但它们永远不会被调用.

这是我的代码.自定义ListPreference取自http://blog.350nice.com/wp/archives/240

import android.content.Context;
import android.content.DialogInterface;
import android.graphics.Color;
import android.preference.ListPreference;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.app.AlertDialog.Builder;

public class CustomListPreference extends ListPreference {

    private boolean[] mClickedDialogEntryIndices;
    CustomListPreferenceAdapter customListPreferenceAdapter = null;
    Context mContext;

    public CustomListPreference(Context context, AttributeSet attrs) {
        super(context, attrs);
        mContext = context;
        mClickedDialogEntryIndices = new boolean[getEntries().length];
    }

    @Override
    protected void onPrepareDialogBuilder(Builder builder) {
        CharSequence[] entries = getEntries();
        CharSequence[] entryValues = getEntryValues();
        if (entries == null || entryValues == null
                || entries.length != entryValues.length) {
            throw new IllegalStateException(
                    "ListPreference requires an entries array "
                    +"and an entryValues array which are both the same length");
        }
        builder.setMultiChoiceItems(entries, mClickedDialogEntryIndices,
                new DialogInterface.OnMultiChoiceClickListener() {

                    public void onClick(DialogInterface dialog, int which,
                            boolean val) {
                        mClickedDialogEntryIndices[which] = val;
                    }
                });
        // setting my custom list adapter
        customListPreferenceAdapter = new CustomListPreferenceAdapter(mContext);
        builder.setAdapter(customListPreferenceAdapter, null);
    }

    private class CustomListPreferenceAdapter extends BaseAdapter {

        public CustomListPreferenceAdapter(Context context) {}

        public int getCount() {
            return 1;
        }

        public Object getItem(int position) {
            return position;
        }

        public long getItemId(int position) {
            return position;
        }

        public View getView(int position, View convertView, ViewGroup parent) {
            convertView.setBackgroundColor(Color.BLUE);
            return convertView;
        }
    }
}

Answer 1

好的,我主要是让这个工作.我不得不使用扩展的自定义类ListPreference.然后我必须创建一个自定义适配器类,就像你一样,ListView并使用它将其设置为构建器builder.setAdapter().我还必须为处理取消检查RadioButtons等的ListView行和行定义侦听器RadioButtons.我仍然有的唯一问题是,我的自定义ListPreference有一个OK和一个Cancel按钮,其中ListPreference只有一个取消按钮.我不知道如何删除确定按钮.此外,当我点击它们时,我不能像常规那样突出显示行ListPreference.

自定义ListPreference类的java代码.请务必注意包名称,首选项名称(键),条目和值ListPreference以及xml项目的名称.

package your.package.here;

import java.util.ArrayList;
import android.content.Context;
import android.content.DialogInterface;
import android.content.SharedPreferences;
import android.graphics.Color;
import android.preference.ListPreference;
import android.preference.PreferenceManager;
import android.util.AttributeSet;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.CompoundButton;
import android.widget.RadioButton;
import android.widget.TextView;
import android.app.Dialog;
import android.app.AlertDialog.Builder;

public class CustomListPreference extends ListPreference
{   
    CustomListPreferenceAdapter customListPreferenceAdapter = null;
    Context mContext;
    private LayoutInflater mInflater;
    CharSequence[] entries;
    CharSequence[] entryValues;
    ArrayList<RadioButton> rButtonList;
    SharedPreferences prefs;
    SharedPreferences.Editor editor;

    public CustomListPreference(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)
    {
        entries = getEntries();
        entryValues = getEntryValues();

        if (entries == null || entryValues == null || entries.length != entryValues.length )
        {
            throw new IllegalStateException(
                    "ListPreference requires an entries array and an entryValues array which are both the same length");
        }

        customListPreferenceAdapter = new CustomListPreferenceAdapter(mContext);

        builder.setAdapter(customListPreferenceAdapter, new DialogInterface.OnClickListener()
        {
            public void onClick(DialogInterface dialog, int which)
            {

            }
        });
    }

    private class CustomListPreferenceAdapter extends BaseAdapter
    {        
        public CustomListPreferenceAdapter(Context context)
        {

        }

        public int getCount()
        {
            return entries.length;
        }

        public Object getItem(int position)
        {
            return position;
        }

        public long getItemId(int position)
        {
            return position;
        }

        public View getView(final int position, View convertView, ViewGroup parent)
        {  
            View row = convertView;
            CustomHolder holder = null;

            if(row == null)
            {                                                                   
                row = mInflater.inflate(R.layout.custom_list_preference_row, parent, false);
                holder = new CustomHolder(row, position);
                row.setTag(holder);

                // do whatever you need here, for me I wanted the last item to be greyed out and unclickable
                if(position != 3)
                {
                    row.setClickable(true);
                    row.setOnClickListener(new View.OnClickListener()
                    {
                        public void onClick(View v)
                        {
                            for(RadioButton rb : rButtonList)
                            {
                                if(rb.getId() != position)
                                    rb.setChecked(false);
                            }

                            int index = position;
                            int value = Integer.valueOf((String) entryValues[index]);
                            editor.putInt("yourPref", value);

                            Dialog mDialog = getDialog();
                            mDialog.dismiss();
                        }
                    });
                }
            }

            return row;
        }

        class CustomHolder
        {
            private TextView text = null;
            private RadioButton rButton = null;

            CustomHolder(View row, int position)
            {    
                text = (TextView)row.findViewById(R.id.custom_list_view_row_text_view);
                text.setText(entries[position]);
                rButton = (RadioButton)row.findViewById(R.id.custom_list_view_row_radio_button);
                rButton.setId(position);

                // again do whatever you need to, for me I wanted this item to be greyed out and unclickable
                if(position == 3)
                {
                    text.setTextColor(Color.LTGRAY);
                    rButton.setClickable(false);
                }

                // also need to do something to check your preference and set the right button as checked

                rButtonList.add(rButton);
                rButton.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener()
                {
                    public void onCheckedChanged(CompoundButton buttonView, boolean isChecked)
                    {
                        if(isChecked)
                        {
                            for(RadioButton rb : rButtonList)
                            {
                                if(rb != buttonView)
                                    rb.setChecked(false);
                            }

                            int index = buttonView.getId();
                            int value = Integer.valueOf((String) entryValues[index]);
                            editor.putInt("yourPref", value);

                            Dialog mDialog = getDialog();
                            mDialog.dismiss();
                        }
                    }
                });
            }
        }
    }
}

我的xml PreferenceActivity.这不是我的完整xml,为了简单起见,取出了我所有的其他首选项.同样,请务必记住包名称,包名称ListPreference必须引用自定义类.还要记住首选项的名称以及包含条目和值的数组名称.

<?xml version="1.0" encoding="utf-8"?>

<PreferenceScreen
    xmlns:android="http://schemas.android.com/apk/res/android">

        <PreferenceCategory
                android:title="Your Title">

                <your.package.here.CustomListPreference
                    android:key="yourPref"
                    android:title="Your Title"
                    android:dialogTitle="Your Title"
                    android:summary="Your Summary"
                    android:defaultValue="1"
                    android:entries="@array/yourArray"
                    android:entryValues="@array/yourValues"/>

        </PreferenceCategory>
</PreferenceScreen>

我的对话框列表视图行的xml.在getView方法中,请确保在膨胀此行的行中使用此xml文件的名称.

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:paddingBottom="8dip"
    android:paddingTop="8dip"
    android:paddingLeft="10dip"
    android:paddingRight="10dip">

    <TableLayout
        android:id="@+id/custom_list_view_row_table_layout"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:stretchColumns="0">

        <TableRow
            android:id="@+id/custom_list_view_row_table_row"
            android:gravity="center_vertical"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content">

            <TextView
                android:id="@+id/custom_list_view_row_text_view"
                android:textSize="22sp"
                android:textColor="#000000"  
                android:gravity="center_vertical"
                android:layout_width="160dip" 
                android:layout_height="40dip" />

            <RadioButton
                android:checked="false"
                android:id="@+id/custom_list_view_row_radio_button"/>
        </TableRow>
    </TableLayout>

</LinearLayout>

最后,在res/values下面是我的array.xml,其中包含的条目名称和值ListPreference.同样,为简单起见缩短了我的范围.

<?xml version="1.0" encoding="utf-8"?>
<resources> 
    <string-array name="yourArray">
        <item>Item 1</item>
        <item>Item 2</item>
        <item>Item 3</item>
        <item>Item 4</item>
    </string-array>

    <string-array name="yourValues">
        <item>0</item>
        <item>1</item>
        <item>2</item>
        <item>3</item>
    </string-array>
</resources>

Answer 2

这对我很有用.我使用了一种Adapter方法,它将一个包装的适配器注入到视图中.

这是基础包装的适配器类:

import android.database.DataSetObserver;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ListAdapter;
import android.widget.WrapperListAdapter;

class ListPrefWrapperAdapter implements WrapperListAdapter {
    private ListAdapter mOrigAdapter;

    public ListPrefWrapperAdapter(ListAdapter origAdapter) {
        mOrigAdapter = origAdapter;
    }

    @Override
    public ListAdapter getWrappedAdapter() {
        return mOrigAdapter;
    }

    @Override
    public boolean areAllItemsEnabled() {
        return getWrappedAdapter().areAllItemsEnabled();
    }

    @Override
    public boolean isEnabled(int position) {
        return getWrappedAdapter().isEnabled(position);
    }

    @Override
    public void registerDataSetObserver(DataSetObserver observer) {
        getWrappedAdapter().registerDataSetObserver(observer);
    }

    @Override
    public void unregisterDataSetObserver(DataSetObserver observer) {
        getWrappedAdapter().unregisterDataSetObserver(observer);
    }

    @Override
    public int getCount() {
        return getWrappedAdapter().getCount();
    }

    @Override
    public Object getItem(int position) {
        return getWrappedAdapter().getItem(position);
    }

    @Override
    public long getItemId(int position) {
        return getWrappedAdapter().getItemId(position);
    }

    @Override
    public boolean hasStableIds() {
        return getWrappedAdapter().hasStableIds();
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        return getWrappedAdapter().getView(position, convertView, parent);
    }

    @Override
    public int getItemViewType(int position) {
        return getWrappedAdapter().getItemViewType(position);
    }

    @Override
    public int getViewTypeCount() {
        return getWrappedAdapter().getViewTypeCount();
    }

    @Override
    public boolean isEmpty() {
        return getWrappedAdapter().isEmpty();
    }
}

以下是使用ListPrefWrapperAdapter的CustomListPreference基类:

import android.app.AlertDialog;
import android.content.Context;
import android.os.Bundle;
import android.util.AttributeSet;
import android.widget.ListAdapter;
import android.widget.ListView;

public class CustomListPreference extends ListPreference {
    public CustomListPreference(Context context) {
        super(context);
    }

    public CustomListPreference(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    @Override
    protected void showDialog(Bundle state) {
        super.showDialog(state);
        AlertDialog dialog = (AlertDialog) getDialog();
        ListView listView = dialog.getListView();
        ListAdapter adapter = listView.getAdapter();
        final ListPrefWrapperAdapter fontTypeAdapter = createWrapperAdapter(adapter);

        // Adjust the selection because resetting the adapter loses the selection.
        int selectedPosition = findIndexOfValue(getValue());
        listView.setAdapter(fontTypeAdapter);
        if (selectedPosition != -1) {
            listView.setItemChecked(selectedPosition, true);
            listView.setSelection(selectedPosition);
        }
    }

    protected ListPrefWrapperAdapter createWrapperAdapter(ListAdapter origAdapter) {
        return new ListPrefWrapperAdapter(origAdapter);
    }

}

最后,以下是执行禁用和启用特定行的派生类:

import android.content.Context;
import android.graphics.Color;
import android.graphics.Typeface;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;
import android.widget.CheckedTextView;
import android.widget.ListAdapter;

public class FontTypePreference extends CustomListPreference {

    public FontTypePreference(Context context) {
        super(context);
    }

    public FontTypePreference(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    @Override
    protected ListPrefWrapperAdapter createWrapperAdapter(ListAdapter origAdapter) {
        return new Adapter(origAdapter);
    }

    private class Adapter extends ListPrefWrapperAdapter {
        private static final float TEXT_SIZE = 25.0f;
        private static final int STARTING_UPGRADE_REQUIRED_INDEX = 8;

        public Adapter(ListAdapter origAdapter) {
            super(origAdapter);
        }

        @Override
        public boolean areAllItemsEnabled() {
            return false;
        }

        @Override
        public boolean isEnabled(int position) {
            return position < STARTING_UPGRADE_REQUIRED_INDEX;
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            CheckedTextView textView = (CheckedTextView) getWrappedAdapter()
                    .getView(position, convertView, parent);
            textView.setTextColor(position < STARTING_UPGRADE_REQUIRED_INDEX ?
                    Color.BLACK : Color.RED);
            return textView;
        }


    }

}

我只在SDK 15及更高版本上测试了这段代码.