Question

请查看我的代码..

public class BseDemo extends Activity {
    final String feedUrlString = "http://www.bseindia.com/sensex/xml-data/sensexrss.xml";
    Uri uri;
    TextView tvs,tvd;
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);


        Bse b = new Bse();
        b.start();


    }
    class Bse extends Thread{
        public void run(){
            try {
                tvs = (TextView)findViewById(R.id.text);
                tvd = (TextView)findViewById(R.id.diff);
                URL url = new URL(feedUrlString);
                DocumentBuilderFactory docBuilderFactory = DocumentBuilderFactory.newInstance();
                DocumentBuilder docBuilder = docBuilderFactory.newDocumentBuilder();
                Document doc = docBuilder.parse (new InputSource(url.openStream()));
                doc.getDocumentElement ().normalize ();
                Element e =  doc.getDocumentElement();
                NodeList nl = e.getElementsByTagName("title");
                Node bse = nl.item(2);
                String sen  = bse.getFirstChild().getNodeValue();
                tvs.setText(sen.substring(0, sen.indexOf("*")));
                tvd.setText(sen.substring(sen.indexOf("*")+1));
                tvd.setBackgroundResource(R.drawable.plus);
            } catch (Exception e) {
                throw new RuntimeException(e);
            }
        }
    }
}

我有上面提到的代码，我得到了异常CalledFromWrongTreadException 请给出一些解决方案。

Answer 1

尝试实现AsyncTask以从文档中获取String（在doInBackground中），然后使用onPostExecute在TextView上设置Text。

在不阻塞UI线程的情况下，是执行后台逻辑的最佳方法。

Answer 2

尝试查看runUIThread（...）函数

当您从其他线程编辑某些UI组件而非“主”线程时，通常会发生该异常;我想问题出在：

tvs.setText(sen.substring(0, sen.indexOf("*")));
tvd.setText(sen.substring(sen.indexOf("*")+1));
tvd.setBackgroundResource(R.drawable.plus);

Answer 3

您无法从非UI线程更新UI（UI线程是调用Activity的onCreate的线程）。要实现您要执行的操作，您需要使用Handler将消息从当前线程发布到UI线程。请看这个答案：android: displaying progress dialog when waiting for connection

从错误的线程异常调用

3 个答案: