helo,我想讀取這個文件中的值:http://www.nbp.pl/kursy/xml/lastC.xml並用它們填充網格。我的應用程序下載此文件並將其保存在SDCard上,等待它運行。我的問題是我的代碼讀取空值。這就是:android,從SD卡中讀取xml文件中的值
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
grid= (GridView)findViewById(R.id.grid);
try{
url = new URL("http://www.nbp.pl/kursy/xml/LastC.xml");
HttpURLConnection connection = (HttpURLConnection)url.openConnection();
connection.setRequestMethod("GET");
connection.setDoOutput(true);
connection.connect();
File dir = new File (android.os.Environment.getExternalStorageDirectory().getAbsolutePath() + "/Kursy Walut");
if(dir.exists()==false)
dir.mkdirs();
File file = new File(dir, "kursywalut.xml");
FileOutputStream fileoutput = new FileOutputStream(file);
InputStream inputstream = connection.getInputStream();
int tempSize=0;
byte[] buffer = new byte[1024];
while((tempSize = inputstream.read(buffer))>0)
{
fileoutput.write(buffer, 0, tempSize);
}
fileoutput.close();
在我的SD卡存儲文件,並舉杯與信息
Toast.makeText(MainActivity.this, "pobrano do Kursy Walut/kursywalut.xml!!", Toast.LENGTH_SHORT).show();
//here i have a array of string witch i will parse into my grid
String[] items=new String[13];
InputStream in = new FileInputStream(file.getPath());
DocumentBuilder builder = DocumentBuilderFactory.newInstance().newDocumentBuilder();
Document doc = builder.parse(in);
NodeList words = doc.getElementsByTagName("pozycja");
for(int i=0; i<words.getLength(); i++)
{
items[i]= ((Element)words.item(i)).getAttribute("kod_waluty");
}
//i setText on some textView to check that i read xmlfile correctly.
text.setText("value: "+items[5]);
in.close();
grid.setAdapter(new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1, items));
}
catch(Throwable t){Toast.makeText(this, t.toString(), Toast.LENGTH_LONG).show();}
}
這個代碼我TextView的文本僅是「值」後沒有任何價值從XML 和我的網格空。我假設我在閱讀XML文件時犯了錯誤。 如果有人可以看看這個,並幫助我解決它,我會非常高興。
更新與更新代碼的問題。 –