Android登錄屏幕變空白

我遇到以下代碼嚴重的問題，並且會很感激任何形式的幫助。Android登錄屏幕變空白

public class WebHandler 
{ 
private String username; 
private String password; 
private boolean errorOccured; 
private String errorMessage; 
private String server; 

public WebHandler(String server) 
{ 
    this.server = server; 
    StrictMode.ThreadPolicy policy = new 
      StrictMode.ThreadPolicy.Builder().permitAll().build(); 
    StrictMode.setThreadPolicy(policy); 
} 

public void setUsername(String username) 
{ 
    this.username = username; 
} 

public void setPassword(String password) 
{ 
    this.password = password; 
} 

public String getInternetData(String url) 
{ 
    BufferedReader bufferedReader = null; 
    String data = null; 

    try 
    { 
     HttpClient client = new DefaultHttpClient(); 
     URI website = new URI("http://google.com"); 
     HttpGet request = new HttpGet(); 
     request.setURI(website); 
     HttpResponse response = client.execute(request); 
     bufferedReader = new BufferedReader(new  
        InputStreamReader(response.getEntity().getContent())); 

     StringBuffer stringBuffer = new StringBuffer(""); 

     String line; 

     while ((line = bufferedReader.readLine()) != null) 
     { 
      stringBuffer.append(line); 
      Log.e("PLW", line); 
     } 

     bufferedReader.close(); 
     data = stringBuffer.toString(); 
    } 
    catch(Exception e) 
    { 
     this.errorOccured = true; 
     this.errorMessage = e.getMessage(); 
    } 

    return data; 

} 

public String Post(List<NameValuePair> nameValuePair, String url) 
{ 
    String result = null; 

    HttpClient httpClient = new DefaultHttpClient(); 
    HttpPost httpPost = new HttpPost("http://www.google.com/"); 

    nameValuePair.add(new BasicNameValuePair("usernmae", this.username)); 
    nameValuePair.add(new BasicNameValuePair("password", this.password)); 

    Log.e("PLW_0", "called post..."); 

    try 
    { 
     httpPost.setEntity(new UrlEncodedFormEntity(nameValuePair)); 
     HttpResponse response = httpClient.execute(httpPost); 
     result = response.toString(); 
     Log.e("PLW_1", "response:" + result); 
    } 
    catch (Exception e) 
    { 
     // writing exception to log 
     Log.e("PLW_2", "Error:", e); 
     Log.e("PLW_3", "error:" + e.getMessage()); 
    } 
    return result; 
} 

public boolean hasError() 
{ 
    return this.errorOccured; 
} 

public String getError() 
{ 
    return this.errorMessage; 
} 
}

來源

2013-02-03 user2038123

能否請你描述你所面臨的 '嚴重的問題'？你是否遇到異常？加載時間過長嗎？ – Brandon

您是否試圖在其他線程中運行您的代碼？避免使用連接或耗時的任務阻塞主線程。

更新時間：

的AsyncTask例子：

來源

2013-02-03 23:56:48 madlymad

是的，那是我最初做的。不幸的是，屏幕只是空白，所以我GOOGLE了它，發現互聯網訪問沒有啓用默認情況下在Android上，所以我不得不使用下面的代碼，這是拋出一個新的一套錯誤信息： \t \t StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder（）。permitAll（）。build（）; \t \t StrictMode.setThreadPolicy（policy）; – user2038123

註釋掉** StrictMode語句**並再次運行代碼後，我得到此行所拋出的異常'HttpPost httpPost = new HttpPost（「http://www.google.com/」）;'調用這個通過這個語句在我的登錄類'WebHandler處理程序=新的WebHandler（「192.xxx」）;列表 nameValuePairs =新ArrayList （）;字符串結果=處理程序.Post（nameValuePairs，「test.txt」） ;'。因此，test.txt只是一個包含** Hello World **的文件。請問我在這裏做錯了什麼？ – user2038123

是什麼例外？操作系統版本的測試？你有沒有試過把你的連接放在AsyncTask中？示例： 1. http://anujarosha.wordpress.com/2012/01/27/handling-http-post-method-in-android/ 2. http://pcfandroid.wordpress.com/2011/07/14/http-post-with-asynctask-android-tutorial/ – madlymad

Android登錄屏幕變空白

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