Question

我已经有一段时间了，我已经卡住了..我已经制作了下面的代码，从JSON获取一个变量，并在文本视图中显示在屏幕上。该应用程序不会崩溃，但它始终显示 IT DISPLAYS THIS !! .. （参见代码）。我无法弄清楚为什么它没有显示文字.. It should display naam from here..

package me.janvandijk.receptenapp;


public class Recept extends Activity {

    String receptid;
    String result;
    TextView receptTitel;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_recept);

    receptid = getIntent().getStringExtra("receptid");
    receptTitel = (TextView)findViewById(R.id.receptTitel);

    //First Initialise TextView
    getMethod method=new getMethod();
    try {
        result = method.getInternetData();// Then get the Json response
    } catch (Exception e) {
        receptTitel.setText("IT DISPLAYS THIS!!..");
        e.printStackTrace();
    }

    try{
        JSONObject json=new JSONObject(result);
        try {
            String receptNaam =json.getString("naam");
            receptTitel.setText(receptNaam);
        } catch (JSONException e) {
            e.printStackTrace();
            receptTitel.setText("Never Seen This..");
        }

    }
    catch (JSONException e) {
        e.printStackTrace();
    }
    catch (Exception e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    //new ReceptAsynTask().execute("http://janvandijk.me/zooi/receptenapp/getrecipes.php?type=request&datatype=recept&id=" + receptid);



   public void setText(String string){
        //tv.setText(string);
    }

    public void showToast(){
        Toast.makeText(getApplicationContext(), "Bezig met laden recept met ID "+receptid, Toast.LENGTH_LONG).show();
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_recept, menu);
        //TextView view = (TextView) findViewById(R.id.testje);
        //view.setText(receptid);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}


public class getMethod {

    public String getInternetData() throws Exception {
        BufferedReader in = null;
        String data = null;
        try {
            HttpClient client = new DefaultHttpClient();
            URI website = new URI("http://janvandijk.me/zooi/receptenapp/getrecipes.php?type=request&datatype=recept&id=1");

            HttpGet request = new HttpGet();
            request.setURI(website);
            HttpResponse response = client.execute(request);
            in = new BufferedReader(new InputStreamReader(response.getEntity().getContent()));
            StringBuffer sb = new StringBuffer("");
            String l = "";
            String nl = System.getProperty("line.separator");
            while ((l = in.readLine()) !=null) {
                sb.append(l + nl);
            }

            in.close();
            data = sb.toString();
            return data;
        }
        finally {
            if (in !=null){
                try{
                    in.close();
                    return data;
                }catch (Exception e){
                    e.printStackTrace();

                }
            }

        }
    }
}

Answer 1

请使用AsyncTask等单独的线程进行网络操作。您在OnCreate（）中使用getMethod会导致异常。

Answer 2

在您的服务器结果中，您将获得json数组，但是当您将其解析为json对象时

JSONObject json = new JSONObject（result）;

这里你的结果是一个字符串类型的json数组，所以你使用下面的代码来解析

JSONObject json = new JSONArray（result）.get（0）;

最后也很重要的是你应该使用AsynkTask来调用Web服务或长时间操作，否则会阻塞你的UI线程。

没有从JSON到textview的结果

2 个答案: