偏好设置(2)偏好设置界面用PreferenceFragment或PreferenceActivity

android应用各参数或配置是用SharedPreference存储管理的,但是它没有界面,如果想用界面,

系统在3.0以上用PreferenceFragment(推荐用它),以下用PreferenceActivity

它们默认有listview显示各配置项,给它们指定一个配置xml文件就可.

下面是示例,它们用相同的xml.

1.效果

2.配置xml: res/xml/my_preference.xml

<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android" >
    <CheckBoxPreference
        android:key="checkbox"
        android:title="是否开启"
        android:summaryOn="开启"
        android:summaryOff="关闭"
        />

    <!-- entries是ListPreference列表项 ,entryValues指定列表项对应的各值-->
    <ListPreference
        android:key="list"
        android:title="请选择一个选项"
        android:summary="请点击选择"
        android:entries="@array/preference_entries"
        android:entryValues="@array/preference_values"
        />
    <EditTextPreference
        android:key="text"
        android:title="请输入"
        android:dialogTitle="请输入名字"
        android:dialogMessage="有劳了"
        android:summary="请再次输入"/>

</PreferenceScreen>

其中用到了list.下面是这个 list各item与各item对应的值. res/values/my_preference.xml

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

    <string-array name="preference_entries">
        <item >Java</item>
        <item >C++</item>
        <item >Assume</item>
    </string-array>
    <string-array name="preference_values">
        <item >eclipse</item>
        <item >visual studio</item>
        <item >notepad++</item>
    </string-array>

</resources>

3.PreferenceFragment.java

import android.os.Bundle;
import android.preference.CheckBoxPreference;
import android.preference.EditTextPreference;
import android.preference.ListPreference;
import android.preference.PreferenceFragment;
import android.preference.PreferenceManager;
import android.widget.Toast;

public class MyPreferenceFrgment extends PreferenceFragment {

    PreferenceManager prefernceMgr;
    CheckBoxPreference checkPreference;
    ListPreference listPreference;
    EditTextPreference editPreference;

    /*
     * 读取各属性
     */
    void readPreference() {
        Toast.makeText(getActivity(), "当前选中状态为:" + checkPreference.isChecked(),
                0).show();
        Toast.makeText(
                getActivity(),
                "当前选中的列表项为:" + listPreference.getEntry() + "当前选中的列表项的值为:"
                        + listPreference.getValue(), 1).show();
        Toast.makeText(getActivity(),
                "当前选中的列表项为:" + "输入的内容为:" + editPreference.getText(), 1).show();
    }
    void init() {
        addPreferencesFromResource(R.xml.my_preference);//关键代码
        prefernceMgr = getPreferenceManager();
        checkPreference = (CheckBoxPreference) prefernceMgr
                .findPreference("checkbox");//checkbox是在xml中定义的android:key
        listPreference = (ListPreference) prefernceMgr.findPreference("list");
        editPreference = (EditTextPreference) prefernceMgr
                .findPreference("text");
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        init();
    }
//    @Override
//    public View onCreateView(LayoutInflater inflater, ViewGroup container,
//            Bundle savedInstanceState) {
//        //注意,如果指定自己的layout,那么该layout必有listview
//        View v = inflater.inflate(R.layout.frgmt_perference, container, false);
//        return v;
//    }
}

4.MyPreferenceActivity.java

import android.os.Bundle;
import android.preference.CheckBoxPreference;
import android.preference.EditTextPreference;
import android.preference.ListPreference;
import android.preference.PreferenceActivity;
import android.preference.PreferenceManager;
import android.preference.RingtonePreference;
import android.widget.Toast;

public class MyPreferenceActivity extends PreferenceActivity {

    PreferenceManager prefernceMgr;
    /*
     * PreferenceActivity主要使用的就是下面几个子preference
     */
    CheckBoxPreference checkPreference;
    ListPreference listPreference;
    EditTextPreference editPreference;
    RingtonePreference rp;

    /*
     * 读取各属性
     */
    private void readPreferences() {

        Toast.makeText(getApplicationContext(),
                "当前选中状态为:" + checkPreference.isChecked(), 0).show();
        Toast.makeText(
                getApplicationContext(),
                "当前选中的列表项为:" + listPreference.getEntry() + "当前选中的列表项的值为:"
                        + listPreference.getValue(), 1).show();
        Toast.makeText(getApplicationContext(),
                "当前选中的列表项为:" + "输入的内容为:" + editPreference.getText(), 1).show();
    }

    private void init(){

        //指定偏好设置的xml文件既可,不用在指定layout文件,PreferenceActivity用listview显示各偏好
        addPreferencesFromResource(R.xml.my_preference);
        prefernceMgr = getPreferenceManager();

        checkPreference = (CheckBoxPreference) prefernceMgr
                .findPreference("checkbox");//checkbox是在xml中定义的android:key
        listPreference = (ListPreference) prefernceMgr.findPreference("list");
        editPreference = (EditTextPreference) prefernceMgr
                .findPreference("text");
    }
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        init();
    }
}