android - XmlResourceParser 为空？

Question

我目前正在创建一个 Android 应用程序，我有一个供用户选择的列表，我希望旁边的每个项目都有一个图像。我已经为列表创建了一个适配器，并为列表创建了一个单独的 list_row 布局。

列表的实际数据存储在本地 res/xml/data.xml 中，如下所示:

<dataset>

    <data>
        <name>all</name>
        <image>all</image>
    </data>
    <data>
        <name>car</name>
        <image>car</image>
    </data>

</dataset>

现在，在这个列表的主要 Activity 上，我尝试从本地源解析 XML 数据，然后将其作为字符串传递给 Document 元素并处理数据。我已经调试了这个问题并注意到下面的行不起作用，因为设置的字符串为空:

XmlResourceParser parserXml = getResources().getXml(R.xml.data);
String xmlString = parserXml.getText();

解析数据的完整代码如下:

    XmlResourceParser parserXml = getResources().getXml(R.xml.dresses);
    String xmlString = parserXml.getText(); // getting XML from URL

XMLParser parser = new XMLParser();
    Document doc = parser.getDomElement(xmlString); // getting DOM element

    NodeList nl = doc.getElementsByTagName(KEY_DATA);

    for (int i = 0; i < nl.getLength(); i++) {

        HashMap<String, String> map = new HashMap<String, String>();
        Element e = (Element) nl.item(i);

        map.put(KEY_NAME, parser.getValue(e, KEY_NAME));
        map.put(KEY_IMAGE, parser.getValue(e, KEY_IMAGE));

        dataInfo.add(map);
    }

任何人都可以帮我解决这个问题，在此先感谢:)

编辑.....

我也尝试过按照建议使用 XmlPullParser 方法，但我仍然遇到相同的问题，即 String 为 null。我使用的代码如下:

XmlPullParser xpp = this.getResources().getXml(R.xml.data);
String xmlString1 = xpp.getText();

如果这有帮助，我将整个文件包含在下面:

public class Dresses extends Activity {

    static final String KEY_DATA = "dress"; // parent node
    static final String KEY_NAME = "name";
    static final String KEY_IMAGE = "image";

    ListView list;
    ItemTypeAdapter adapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);


        ArrayList<HashMap<String, String>> itemTypes = new ArrayList<HashMap<String, String>>();

        XmlPullParserFactory factory;
        try {
            factory = XmlPullParserFactory.newInstance();
            factory.setNamespaceAware(true);
        } catch (XmlPullParserException e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
        }


        XmlPullParser xpp = this.getResources().getXml(R.xml.data);
        String xmlString1 = xpp.getText();
            Log.d("Testing Type List Data: ", xmlString1);

        XmlResourceParser parserXml = getResources().getXml(R.xml.data);
        String xmlString = parserXml.getText(); // getting XML from URL
        Log.d("Type List Data: ", xmlString);

        XMLParser parser = new XMLParser();
        Document doc = parser.getDomElement(xmlString); // getting DOM element

        NodeList nl = doc.getElementsByTagName(KEY_DATA);

        for (int i = 0; i < nl.getLength(); i++) {

            HashMap<String, String> map = new HashMap<String, String>();
            Element e = (Element) nl.item(i);

            map.put(KEY_NAME, parser.getValue(e, KEY_NAME));
            map.put(KEY_IMAGE, parser.getValue(e, KEY_IMAGE));

            itemTypes.add(map);
        }

        list=(ListView)findViewById(R.id.list);

        // Getting adapter by passing xml data ArrayList
        adapter=new ItemTypeAdapter(this, itemTypes);
        list.setAdapter(adapter);

        // listening to single list item on click
        list.setOnItemClickListener(new OnItemClickListener() {
          public void onItemClick(AdapterView<?> parent, View view,
              int position, long id) {

              // selected item
              String type = ((TextView) view).getText().toString();

              // Launching new Activity on selecting single List Item
              Intent i = new Intent(getApplicationContext(), ItemListActivity.class);
              // sending data to new activity
              i.putExtra("type", type);
              startActivity(i);

          }
        });
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.data, menu);
        return true;
    }

}

Answer 1

确保您在 Activity 中调用它。如果它仍然不起作用，那么也尝试使用 XmlPullParserFactory

XmlPullParserFactory factory = XmlPullParserFactory.newInstance();
    factory.setNamespaceAware(true);

    XmlPullParser xpp = context.getResources().getXml(R.xml.data);

    int eventType = xpp.getEventType();
    while (eventType != XmlPullParser.END_DOCUMENT) {
     if(eventType == XmlPullParser.START_DOCUMENT) {
         System.out.println("Start document");
     } else if(eventType == XmlPullParser.START_TAG) {
         System.out.println("Start tag "+xpp.getName());
     } else if(eventType == XmlPullParser.END_TAG) {
         System.out.println("End tag "+xpp.getName());
     } else if(eventType == XmlPullParser.TEXT) {
         System.out.println("Text "+xpp.getText());
     } else if(eventType == XmlPullParser.TEXT) {
     }
     eventType = xpp.next();
    }
    System.out.println("End document");

这对我有用

package com.example.test4;

import java.io.IOException;

import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlPullParserException;
import org.xmlpull.v1.XmlPullParserFactory;

import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.widget.ListView;

public class MainActivity extends Activity {

   static final String KEY_DATA = "dress"; // parent node
   static final String KEY_NAME = "name";
   static final String KEY_IMAGE = "image";

   ListView list;

   // ItemTypeAdapter adapter;

   @Override
   public void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);

      XmlPullParserFactory factory = null;
      try {
         factory = XmlPullParserFactory.newInstance();
      } catch (XmlPullParserException e) {
         // TODO Auto-generated catch block
         e.printStackTrace();
      }
      factory.setNamespaceAware(true);

      XmlPullParser xpp = getResources().getXml(R.xml.data);

      int eventType = 0;
      try {
         eventType = xpp.getEventType();
      } catch (XmlPullParserException e) {
         // TODO Auto-generated catch block
         e.printStackTrace();
      }
      while (eventType != XmlPullParser.END_DOCUMENT) {
         if (eventType == XmlPullParser.START_DOCUMENT) {
            System.out.println("Start document");
         } else if (eventType == XmlPullParser.START_TAG) {
            System.out.println("Start tag " + xpp.getName());
         } else if (eventType == XmlPullParser.END_TAG) {
            System.out.println("End tag " + xpp.getName());
         } else if (eventType == XmlPullParser.TEXT) {
            System.out.println("Text " + xpp.getText());
         } else if (eventType == XmlPullParser.TEXT) {
         }
         try {
            eventType = xpp.next();
         } catch (XmlPullParserException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
         } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
         }
      }
      System.out.println("End document");

   }

   @Override
   public boolean onCreateOptionsMenu(Menu menu) {
      getMenuInflater().inflate(R.menu.activity_main, menu);
      return true;
   }
}

这是输出

04-05 14:37:08.690: I/System.out(27153): Start document
04-05 14:38:48.185: I/System.out(27153): Start document
04-05 14:39:30.795: I/System.out(27153): Start tag dataset
04-05 14:40:09.540: I/System.out(27153): Start tag data
04-05 14:40:09.540: I/System.out(27153): Start tag name
04-05 14:40:09.540: I/System.out(27153): Text all
04-05 14:40:09.540: I/System.out(27153): End tag name
04-05 14:40:09.540: I/System.out(27153): Start tag image
04-05 14:40:09.540: I/System.out(27153): Text all
04-05 14:40:09.540: I/System.out(27153): End tag image
04-05 14:40:09.540: I/System.out(27153): End tag data
04-05 14:40:09.540: I/System.out(27153): Start tag data
04-05 14:40:09.545: I/System.out(27153): Start tag name
04-05 14:40:09.545: I/System.out(27153): Text car
04-05 14:40:09.550: I/System.out(27153): End tag name
04-05 14:40:09.550: I/System.out(27153): Start tag image
04-05 14:40:09.550: I/System.out(27153): Text car
04-05 14:40:09.550: I/System.out(27153): End tag image
04-05 14:40:09.550: I/System.out(27153): End tag data
04-05 14:40:09.550: I/System.out(27153): End tag dataset
04-05 14:40:09.555: I/System.out(27153): End document

res/xml/data.xml 中的Data.xml

<?xml version="1.0" encoding="utf-8"?>
<dataset>
    <data>
        <name>all</name>
        <image>all</image>
    </data>
    <data>
        <name>car</name>
        <image>car</image>
    </data>
</dataset>