androidxml解析&;首选项错误
我正在解析一个xml文件,并且不断得到一个空指针异常。我不知道这里的空指针是:( ListView.javaandroidxml解析&;首选项错误,android,xml,preference,Android,Xml,Preference,我正在解析一个xml文件,并且不断得到一个空指针异常。我不知道这里的空指针是:( ListView.java static String URL = "https://dl.dropbox.com/u/####/wosm-library-EN.xml"; static final String KEY_ITEM = "item"; static final String KEY_ID = "id"; static final String KEY_TITLE = "title"; st
static String URL = "https://dl.dropbox.com/u/####/wosm-library-EN.xml";
static final String KEY_ITEM = "item";
static final String KEY_ID = "id";
static final String KEY_TITLE = "title";
static final String KEY_DESCRIPTION = "description";
static final String KEY_FILESIZE = "filesize";
static final String KEY_THUMB_URL = "thumb_url";
static final String KEY_DOCUMENT_URL = "document_url";
SharedPreferences sharedPrefs = PreferenceManager.getDefaultSharedPreferences(this);
ListView list;
LazyAdapter adapter;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.library);
sharedPrefs.getBoolean("french", false); {
URL="https://dl.dropbox.com/u/######/wosm-library-EN.xml";
}
sharedPrefs.getBoolean("french", true);
{
URL="https://dl.dropbox.com/u/######/wosm-library-FR.xml";
}
ArrayList<HashMap<String, String>> libraryList = new ArrayList<HashMap<String, String>>();
XMLParser parser = new XMLParser();
String xml = parser.getXmlFromUrl(URL);
Document doc = parser.getDomElement(xml);
NodeList nl = doc.getElementsByTagName(KEY_ITEM);
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_ID, parser.getValue(e, KEY_ID));
map.put(KEY_TITLE, parser.getValue(e, KEY_TITLE));
map.put(KEY_DESCRIPTION, parser.getValue(e, KEY_DESCRIPTION));
map.put(KEY_FILESIZE, parser.getValue(e, KEY_FILESIZE));
map.put(KEY_THUMB_URL, parser.getValue(e, KEY_THUMB_URL));
map.put(KEY_DOCUMENT_URL, parser.getValue(e, KEY_DOCUMENT_URL));
libraryList.add(map);
}
list=(ListView)findViewById(R.id.list);
adapter=new LazyAdapter(this, libraryList);
list.setAdapter(adapter);
list.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
String title = ((TextView) view.findViewById(R.id.title)).getText().toString();
String description = ((TextView) view.findViewById(R.id.artist)).getText().toString();
//String thumb_url = ((ImageView)view.findViewById(R.id.list_image)).getImageMatrix().toString();
//String thumb_url = ((TextView) view.findViewById(R.id.thumburl)).getText().toString();
String filesize = ((TextView) view.findViewById(R.id.duration)).getText().toString();
String thumburl = ((TextView) view.findViewById(R.id.imgurl)).getText().toString();
String doc_url = ((TextView) view.findViewById(R.id.documenturl)).getText().toString();
Intent in = new Intent(CustomizedListView.this, org.scouts.library.SingleMenuItem.class);
in.putExtra(KEY_TITLE, title);
in.putExtra(KEY_DESCRIPTION, description);
//in.putExtra(KEY_THUMB_URL, thumb_url);
in.putExtra(KEY_FILESIZE, filesize);
in.putExtra(KEY_THUMB_URL, thumburl);
in.putExtra(KEY_DOCUMENT_URL, doc_url);
startActivity(in);
}
});
}
}
静态字符串URL=”https://dl.dropbox.com/u/####/wosm-图书馆EN.xml”;
静态最终字符串键\u ITEM=“ITEM”;
静态最终字符串键\u ID=“ID”;
静态最终字符串键\u TITLE=“TITLE”;
静态最终字符串键\u DESCRIPTION=“DESCRIPTION”;
静态最终字符串键\u FILESIZE=“FILESIZE”;
静态最终字符串键\u THUMB\u URL=“THUMB\u URL”;
静态最终字符串KEY\u DOCUMENT\u URL=“DOCUMENT\u URL”;
SharedPreferences SharedPrefers=PreferenceManager.getDefaultSharedPreferences(此);
列表视图列表;
懒散适配器;
@凌驾
创建时的公共void(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.library);
sharedPrefs.getBoolean(“法语”,false){
URL=”https://dl.dropbox.com/u/######/wosm-图书馆EN.xml”;
}
getBoolean(“法语”,true);
{
URL=”https://dl.dropbox.com/u/######/wosm-library-FR.xml”;
}
ArrayList libraryList=新的ArrayList();
XMLParser=新的XMLParser();
字符串xml=parser.getXmlFromUrl(URL);
Document doc=parser.getdoElement(xml);
NodeList nl=doc.getElementsByTagName(键项);
对于(int i=0;i
我只是在添加了preference变量后才开始获取nullpointer excepetion,将SharedPreferences行放入onCreate()方法中 您还需要使用
if(){//do something}else{//do something}
SharedPreferences sharedPrefs = PreferenceManager.getDefaultSharedPreferences(this);
if(sharedPrefs.getBoolean("french", false))
{
URL="https://dl.dropbox.com/u/######/wosm-library-EN.xml";
}
else
{
URL="https://dl.dropbox.com/u/######/wosm-library-FR.xml";
}
更好的方法是为Dropbox URL使用一个资源字符串,并提供不同的本地化。这样您就根本不需要这些代码。请添加您的logcat错误。它可以工作,但当我在首选项中启用法语时,它无法解析法语URL-检查过的URL,并且它没有中断。您需要设置断点并执行步骤通过代码查看失败的地方。同时查看您的logcat输出…您可以将其附加到您的问题中