Android WebView無法在一個活動中加載網址，但在另一個活動中加載

Question

我有一個ListView，點擊一個項目後，一個新的活動通過交付意向來調用。所有活動都有一個webview，並在同一個url中加載不同的url或不同的部分（同一個url的不同div元素）。

我面臨的問題是隻有一個Activity在web視圖中加載url，剩下的顯示一個空白的webview。這可能是Jsoup的問題嗎？

另請注意，當我只運行Jsoup代碼來獲取數據並輸出到控制檯時，它可以工作;但不是當我在活動中使用它時。

以下是兩項活動的代碼（它們僅在doc.select()的單行中有所不同）。活動1工作得很好，並在web視圖中顯示html，而活動2顯示一個空白屏幕。

活動1：

public class Article extends Activity { 

ProgressDialog mProgressDialog; 
WebView wv; 

private static final int SUCCESS = 1; 
private static final int NETWORK_ERROR = 2; 
private static final int ERROR = 3; 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.article); 
    wv = (WebView) findViewById(R.id.webview1); 

    new getHtml().execute(); 
} 

private class getHtml extends AsyncTask<String, Void, Integer> { 
    Elements tfa; 

    @Override 
    protected void onPreExecute() { 
     mProgressDialog = new ProgressDialog(Article.this); 
     mProgressDialog.setTitle("Wikipedia"); 
     mProgressDialog.setMessage("Loading today's featured article..."); 
     mProgressDialog.setIndeterminate(false); 
     mProgressDialog.show(); 
    } 

    @Override 
    protected Integer doInBackground(String... params) { 
     try { 
      // Connect to the web site 
      Document doc = Jsoup.connect(MainActivity.url).get(); 

      tfa = doc.select("div#mp-tfa"); 
      return SUCCESS; 
     } catch (UnknownHostException e) { 
      Log.e("Unknown Host Exception", "Network error", e); 
      return NETWORK_ERROR; 
     } catch (IOException e) { 
      Log.e("IO Exception", "Failed to load HTML", e); 
      return ERROR; 
     } catch (Exception e) { 
      Log.e("Exception", "An exception occured", e); 
      return ERROR; 
     } 

    } 

    @Override 
    protected void onPostExecute(Integer result) { 

     if (result == 2) { 
      Toast.makeText(
        getApplicationContext(), 
        "Network connection error. Check your internet connection and try again.", 
        Toast.LENGTH_LONG).show(); 
     } else if (result == 3) { 
      Toast.makeText(getApplicationContext(), 
        "Unknown error. Failed to load wikipedia.", 
        Toast.LENGTH_LONG).show(); 
     } else if (result == 1) { 
      wv.setWebViewClient(new WebViewClient()); 

      String tfa_html = tfa.outerHtml(); 
      tfa_html = tfa_html.replaceAll("a href=\"/wiki/", 
        "a href=\"http://en.wikipedia.org/wiki/"); 
      tfa_html = tfa_html.replaceFirst(
        "src=\"//upload.wikimedia.org/", 
        "src=\"http://upload.wikimedia.org/"); 
      wv.loadData(tfa_html, "text/html", null); 
     } 

     mProgressDialog.dismiss(); 
    } 
} 

@Override 
public boolean onKeyDown(int keyCode, KeyEvent event) { 
    // Check if the key event was the Back button and if there's history 
    if ((keyCode == KeyEvent.KEYCODE_BACK) && wv.canGoBack()) { 
     wv.goBack(); 
     return true; 
    } 

    return super.onKeyDown(keyCode, event); 
} 

} 

活動2：

public class Article extends Activity { 

ProgressDialog mProgressDialog; 
WebView wv; 

private static final int SUCCESS = 1; 
private static final int NETWORK_ERROR = 2; 
private static final int ERROR = 3; 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.article); 
    wv = (WebView) findViewById(R.id.webview1); 

    new getHtml().execute(); 
} 

private class getHtml extends AsyncTask<String, Void, Integer> { 
    Elements tfa; 

    @Override 
    protected void onPreExecute() { 
     mProgressDialog = new ProgressDialog(Article.this); 
     mProgressDialog.setTitle("Wikipedia"); 
     mProgressDialog.setMessage("Loading today's featured article..."); 
     mProgressDialog.setIndeterminate(false); 
     mProgressDialog.show(); 
    } 

    @Override 
    protected Integer doInBackground(String... params) { 
     try { 
      // Connect to the web site 
      Document doc = Jsoup.connect(MainActivity.url).get(); 

      tfa = doc.select("div#mp-tfp"); 
      return SUCCESS; 
     } catch (UnknownHostException e) { 
      Log.e("Unknown Host Exception", "Network error", e); 
      return NETWORK_ERROR; 
     } catch (IOException e) { 
      Log.e("IO Exception", "Failed to load HTML", e); 
      return ERROR; 
     } catch (Exception e) { 
      Log.e("Exception", "An exception occured", e); 
      return ERROR; 
     } 

    } 

    @Override 
    protected void onPostExecute(Integer result) { 

     if (result == 2) { 
      Toast.makeText(
        getApplicationContext(), 
        "Network connection error. Check your internet connection and try again.", 
        Toast.LENGTH_LONG).show(); 
     } else if (result == 3) { 
      Toast.makeText(getApplicationContext(), 
        "Unknown error. Failed to load wikipedia.", 
        Toast.LENGTH_LONG).show(); 
     } else if (result == 1) { 
      wv.setWebViewClient(new WebViewClient()); 

      String tfa_html = tfa.outerHtml(); 
      tfa_html = tfa_html.replaceAll("a href=\"/wiki/", 
        "a href=\"http://en.wikipedia.org/wiki/"); 
      tfa_html = tfa_html.replaceFirst(
        "src=\"//upload.wikimedia.org/", 
        "src=\"http://upload.wikimedia.org/"); 
      wv.loadData(tfa_html, "text/html", null); 
     } 

     mProgressDialog.dismiss(); 
    } 
} 

@Override 
public boolean onKeyDown(int keyCode, KeyEvent event) { 
    // Check if the key event was the Back button and if there's history 
    if ((keyCode == KeyEvent.KEYCODE_BACK) && wv.canGoBack()) { 
     wv.goBack(); 
     return true; 
    } 

    return super.onKeyDown(keyCode, event); 
} 

} 

Answer 1

找出問題，問題是從移動瀏覽器/應用程序加載時頁面被剝離內容。這就是這個問題的原因。僅供參考，網址爲http://en.wikipedia.org/wiki/Main_Page，重定向到維基百科的移動版本。

我發現的解決方案是從單獨的wiki頁面獲取數據，而不是從主頁面選取數據，或者使用http://en.wikipedia.org/w/index.php?title=Main_Page作爲URL，因爲這不會重定向到移動版本。

Answer 2

活性1： ... TFA = doc.select（ 「DIV＃MP-TFA」） ; ...

活動2： ... tfa = doc.select（「div＃mp-tfp」）; ...

是不同的。

也許MainActivity.url的響應不是「div＃mp-tfp」的節點。只存在「div＃mp-tfa」的節點。