無法顯示服務器的

Question

在這裏，我正在嘗試從服務器的響應並顯示它響應，但我沒有這樣做，響應文本不顯示在我的文字來看，insetead字符串的默認值不，請問我該如何實現自己的目標？以及爲什麼我的代碼無法完成任務。

這裏是我的Android程序：

public class Chico extends Activity { 

GrabURL grab; 
TextView mRespond; 
String line; 

@Override 
public void onCreate(Bundle savedInstanceState) { 

    //create the activity 
    super.onCreate(savedInstanceState); 

    //set up the layout 
    setContentView(R.layout.activity_chico); 

    mRespond = (TextView) findViewById(R.id.Respond); 
    mRespond.setVisibility(View.GONE); 

    grab = new GrabURL(); 
     line = "line"; 

    //set up the button for check in 
    Button btnin = (Button) findViewById(R.id.inbutton); 
    btnin.setOnClickListener(new View.OnClickListener() { 
     @Override 
     public void onClick(View v) { 
      // TODO Auto-generated method stub 
      //set the values 
      grab.onPreExecute("TechID", Build.SERIAL); 
      grab.onPreExecute("Type", "Checkin"); 
      //set the destination and send the request 
      grab.execute(new String[]{"http://192.168.1.150/Me/testing.php"}); 
      //close the activity 
      mRespond.setVisibility(View.VISIBLE); 
      mRespond.setText(line); 
      //finish(); 
     } 
    }); 
} 

private class GrabURL extends AsyncTask<String, Void, Void>{ 
    //ArrayList object for storing the string pairs 
    ArrayList<NameValuePair> nameValuePairs; 

    public GrabURL() { 
     //constructor of the class 
     nameValuePairs = new ArrayList<NameValuePair>(); 
     } 


    protected void onPreExecute(String key, String value) { 
     //store the pair of values into the ArrayList 
     nameValuePairs.add(new BasicNameValuePair(key,value)); 
     } 

    @Override 
    protected Void doInBackground(String... urls) { 
     // TODO Auto-generated method stub 
     //Operation being executed in another thread 
     try{ 
      //set up the type of HTTPClient 
      HttpClient client = new DefaultHttpClient(); 
      //set up the location of the server 
      HttpPost post = new HttpPost(urls[0]); 
      //translate form of pairs to UrlEncodedFormEntity 
      UrlEncodedFormEntity ent = new UrlEncodedFormEntity(nameValuePairs,HTTP.UTF_8); 
      //set up the entity being sent by post method 
      post.setEntity(ent); 
      //execute the url and post the values 
      HttpResponse responsePOST = client.execute(post); 
      HttpEntity resEntity = responsePOST.getEntity(); 
      line = EntityUtils.toString(resEntity); 
     } catch (Exception e) { 
      //catch the exception 
      line = "Can't connect to server"; 
     } 
     return null; 
    } 

    protected void onPostExecute(Void unused) { 
     Toast.makeText(getApplicationContext(), "Value updated", Toast.LENGTH_SHORT).show(); 
    } 
    } 

} 

這裏是PHP文件，它只是打印一行：

<?php 
print "testing";  
?> 

Answer 1

移動這個代碼到你AsyncTask的onPostExecute()：

... 
mRespond.setVisibility(View.VISIBLE); 
mRespond.setText(line);