动态的改变PreferenceActivity中 EditTextPreference，ListPreference的summary值

package com.xxxx.xxxx.activity;

import android.content.Context;
import android.content.SharedPreferences;
import android.content.SharedPreferences.Editor;
import android.content.SharedPreferences.OnSharedPreferenceChangeListener;
import android.os.Bundle;
import android.preference.ListPreference;
import android.preference.Preference;
import android.preference.PreferenceManager;
import android.preference.PreferenceScreen;
import android.preference.Preference.OnPreferenceChangeListener;
import android.preference.EditTextPreference;
import android.util.Log;
import android.widget.Toast;

import com.xxxx.xxxx.R;
/**
 * 
 * 个人设置
 * 
 */
public class PreferenceActivity extends android.preference.PreferenceActivity implements OnPreferenceChangeListener
{
	private static final String TAG = "PreferenceActivity";
	private Context mCtx;

	private SharedPreferences mPreferences;

	@Override
	protected void onCreate(Bundle savedInstanceState)
	{
		super.onCreate(savedInstanceState);
		addPreferencesFromResource(R.xml.preference);
		mCtx = this;
		mPreferences = PreferenceManager.getDefaultSharedPreferences(mCtx);
		
			
	}
                @Override
	public boolean onPreferenceTreeClick(PreferenceScreen preferenceScreen, Preference preference)
	{
		preference.setOnPreferenceChangeListener(new OnPreferenceChangeListener() {
			
			@Override
			public boolean onPreferenceChange(Preference preference, Object newValue) {
				
				String key=preference.getKey();
				if(key.equals("editkey")){
					//动态改变summary的值			
					if(((String) newValue).trim().equals(""))
						preference.setSummary(R.string.xxxx);
		          	else
		          		preference.setSummary(getResources().getString(R.string.xxxx)+newValue);
					
				}else if(key.equals("listkey")){
					preference.setSummary(getResources().getString(R.string.xxxx)+newValue);
				}
				return true;
			
			}
			
		});
		
				return true;
	}
	
		
		

}