運行方法沒有調用線程

Question

我想分析xml使用一個單獨的線程。整個代碼的小代碼片段如下：

Thread t = new Thread(new Runnable() { 
     @Override 
     public void run() { 
      try{ 
      c=c1; 
      URL url = new URL(url1); 
      HttpURLConnection con= (HttpURLConnection) url.openConnection(); 
      InputStream i= con.getInputStream(); 
      xf=XmlPullParserFactory.newInstance(); 
      xp=xf.newPullParser(); 
      xp.setInput(i,null); 
      parseXML(xp,c); 
     } 
     catch(Exception e) 
     { 
      e.printStackTrace(); 

     } 


     } 
    }); 
    t.start(); 

但似乎運行方法沒有被調用本身。有人可以幫助我找出我在這裏錯過了什麼。

編輯： 以下是有關XML整個代碼：

public void fetchXml(String u,final Context c1) throws IOException, XmlPullParserException, InterruptedException { 
    Thread t = new Thread(new Runnable() { 
     @Override 
     public void run() { 
      try{ 

      c=c1; 
       URL url = new URL(url1); 
      HttpURLConnection con= (HttpURLConnection) url.openConnection(); 
      InputStream i= con.getInputStream(); 
      xf=XmlPullParserFactory.newInstance(); 
      xp=xf.newPullParser(); 
      xp.setInput(i,null); 
      parseXML(xp,c); 
     } 
     catch(Exception e) 
     { 

      e.printStackTrace(); 

     } 
    } 
    }); 

    t.start(); 
    t.join(); 
    } 


    public void parseXML(XmlPullParser xp,Context c) throws XmlPullParserException, IOException { 

    int event; 
    String text=null; 
    Toast.makeText(c, "inside parse", Toast.LENGTH_LONG).show(); 

    event=xp.getEventType(); 

    while(event!=XmlPullParser.END_DOCUMENT) 
    { 

     String name=xp.getName(); 

     switch(event) 
     { 

      case XmlPullParser.START_TAG : 
       break; 

      case XmlPullParser.TEXT : 
       text=xp.getText(); 
       break; 

      case XmlPullParser.END_TAG : 
       if(name.equals("country")){ 
        country=text; 
        Toast.makeText(c, "Country"+country, Toast.LENGTH_LONG).show(); 
       } 
       else if(name.equals("humidity")){ 

        humidity=xp.getAttributeValue(null,"value"); 
        Toast.makeText(c, "humidity"+humidity, Toast.LENGTH_LONG).show(); 
       } 

       else if (name.equals("pressure")) 
       { 
        pressure=xp.getAttributeValue(null,"value"); 
        Toast.makeText(c, "pressure"+pressure, Toast.LENGTH_LONG).show(); 
       } 
       else{} 
       break; 
    } 
     event=xp.next(); 
    } 
    parsingcomplete=true; 
    } 

此外，當我檢查了logcat的我收到以下錯誤的吐司聲明，我寫在上面的parsexml函數內。

04-11 07:59:08.891 31361-31580/com.example.hp.xmlparsing W/System.err: java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare() 
04-11 07:59:08.892 31361-31580/com.example.hp.xmlparsing W/System.err:  at android.os.Handler.<init>(Handler.java:200) 

它看起來像run方法運行fine..but我得到異常：

java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare() 

能有人幫...

Answer 1

運行

Toast.makeText(c, "inside parse", Toast.LENGTH_LONG).show(); 

裏面的GUI線程：

runOnUiThread(new Runnable() { 

        @Override 
        public void run() { 
         Toast.makeText(c, "inside parse", Toast.LENGTH_LONG).show(); 
        } 
       });