Question

好的，我现在非常沮丧，我有一个我设置完全相同的花药文件，但由于某种原因，这只是不想工作。我有一个PreferenceScreen xml文件，如下所示：

<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">
    <EditTextPreference 
        android:summary="@string/alias_summary" 
        android:key="alias" 
        android:title="@string/alias_title"/>
     <EditTextPreference 
        android:summary="@string/server_url_summary" 
        android:key="server_url" 
        android:title="@string/server_url_title" 
        android:defaultValue="http://www.myserverhere.com"/>

    <ListPreference 
         android:summary="@string/main_bg_list_pref_summary"
         android:title="@string/main_bg_list_pref_title" 
         android:key="main_view_bg_list_pref"
         android:entries="@array/color_names"
         android:entryValues="@array/color_values"
         android:defaultValue="white"/>
    <EditTextPreference />

</PreferenceScreen>

当我尝试在我的活动中调用服务器URL（抱歉我必须删除实际链接，但它完全相同）时，它只是不会显示但是如果我强制解析该服务器URL ，它就像一个魅力。我不知道为什么它不会看到这个pref ..任何帮助将不胜感激!!

这是我的活动代码：

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.URI;
import java.util.ArrayList;
import java.util.HashMap;

import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;

import android.app.ListActivity;
import android.content.SharedPreferences;
import android.content.SharedPreferences.OnSharedPreferenceChangeListener;
import android.graphics.Color;

import android.os.Bundle;

import android.util.Log;
import android.view.View;
import android.widget.SimpleAdapter;
import android.widget.Toast;

public class ReviewsByCategory  extends ListActivity implements OnSharedPreferenceChangeListener
{
    SharedPreferences prefs;
    ArrayList<HashMap<String,String>> reviews = new ArrayList<HashMap<String,String>>();
    View linearLayoutCustomList;
    private final static String TAG = "ReviewsByCategory";

    protected void onCreate(Bundle savedInstanceState) 
    {

        super.onCreate(savedInstanceState);
        this.setContentView(R.layout.remote_list);


        linearLayoutCustomList = findViewById(R.id.customList);

        displayReviews();
    }

    private void displayReviews() 
    {
        String[] fields = new String[]{"date", "description", "addinfo", "review", "rating", "alias"};
        int[] ids = new int[]{R.id.date, R.id.description, R.id.addInfo, R.id.review, R.id.rating, R.id.alias};
        SimpleAdapter adapter = new SimpleAdapter(this, reviews, R.layout.remote_row, fields, ids);

         Log.d(TAG, "just before populate list");
        populateList();
        this.setListAdapter(adapter);
    }

    private void populateList() 
    {

        BufferedReader in = null;

        try
        {
            String category = getIntent().getExtras().getString("CATEGORY");
            category = "?CATEGORY=" + category;
            //THIS WILL NOT WORK
            //String server = prefs.getString("server_url", "http://www.myserverhere.com" + category);
            //THIS WILL WORK
            String server = "http://www.myserverhere.com" + category;

            HttpClient client = new DefaultHttpClient();
            HttpGet request = new HttpGet();
            request.setURI(new URI(server));
            HttpResponse response = client.execute(request);
            in = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));
            String line = "";

            while((line = in.readLine()) != null)
            {
                HashMap<String, String> temp = new HashMap<String, String>();
                temp.put("date", line);

                if((line = in.readLine()) != null)
                {
                    temp.put("description", line);
                }
                if((line = in.readLine()) != null)
                {
                    temp.put("addinfo", line);
                }
                if((line = in.readLine()) != null)
                {
                    temp.put("review", line);
                }
                if((line = in.readLine()) != null)
                {
                    temp.put("rating", line);
                }
                if((line = in.readLine()) != null)
                {
                    temp.put("alias", line);
                }
                reviews.add(temp);
            }
        }
        catch(Exception e)
        {
            Toast.makeText(this, "Error: " + e, Toast.LENGTH_LONG).show();
        }

    }

    public void onSharedPreferenceChanged(SharedPreferences arg0, String arg1) 
    {
        linearLayoutCustomList = findViewById(R.id.customList);
        String bg = prefs.getString("custom_list_bg_color", "#000000");
        linearLayoutCustomList.setBackgroundColor(Color.parseColor(bg));
    }
}

Answer 1

假设它使server_url正常，它没有获得该类别。如果找不到server_url，您只需添加类别。

换句话说，而不是

String server = 
prefs.getString("server_url", "http://www.myserverhere.com" + category);

你应该写

String server = 
prefs.getString("server_url", "http://www.myserverhere.com") + category;

Answer 2

我添加这一行后工作正常：

prefs = PreferenceManager.getDefaultSharedPreferences(this);

Android首选项字符串在Activity中不起作用

2 个答案: