我如何在 AsyncTask 中应用 alertDialog 作为服务器响应
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【中文标题】我如何在 AsyncTask 中应用 alertDialog 作为服务器响应【英文标题】：How i can apply alertDialog as server response in AsyncTask 【发布时间】：2018-04-23 09:03:34 【问题描述】：我正在尝试通过cPanel Hosting 将我的项目app 与在线数据库连接起来。我使用了AlertDialog.Builder，setOnClickListener，
用于显示服务器的响应，但似乎我遇到了一些错误，任何答案将不胜感激谢谢
这是我的 java 文件。
//Calling my AsyncTask
@Override
public void onClick(View view)
view.setEnabled(false);
Intent launchactivity = new Intent(MainActivity.this,MainActivity.class);
startActivity(launchactivity);
tvscancontent = tvScanContent.getText().toString();
tvscanformat = tvScanFormat.getText().toString();
BackgroundTask backgroundTask = new BackgroundTask();
backgroundTask.execute(tvscancontent,tvscanformat);
finish();
showShowView2();
// displaynotification();
);
private class BackgroundTask extends AsyncTask<String,Void,String> // i got crash here
Context context;
String add_info_url;
private Object activity;
public BackgroundTask()
@Override
protected void onPreExecute()
add_info_url = "http://www.d48.asia/shan/index.php";
progressDialog = new ProgressDialog(MainActivity.this);
progressDialog.setTitle("Processing...");
progressDialog.setMessage("Authenticating...");
progressDialog.setCancelable(false);
progressDialog.setIndeterminate(true);
progressDialog.setProgressStyle(progressDialog.STYLE_SPINNER);
progressDialog.show();
@Override
protected String doInBackground(String... args)
String tvscancontent = args[0];
String tvscanformat = args[1];
String response = "";
String line = "";
try
URL url = new URL(add_info_url);
HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
httpURLConnection.setRequestMethod("POST");
httpURLConnection.setDoOutput(true);
httpURLConnection.setDoInput(true);
OutputStream outputStream = httpURLConnection.getOutputStream();
BufferedWriter bufferedWriter = new BufferedWriter(new OutputStreamWriter(outputStream, "UTF-8"));
String data_string = URLEncoder.encode("tvscancontent", "UTF-8") + "=" + URLEncoder.encode(tvscancontent, "UTF-8")+ "&" +
URLEncoder.encode("tvscanformat", "UTF-8") + "=" + URLEncoder.encode(tvscanformat, "UTF-8");
bufferedWriter.write(data_string);
bufferedWriter.flush();
bufferedWriter.close();
outputStream.close();
InputStream inputStream = httpURLConnection.getInputStream();
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream,"iso-8859-1"));
while ((line = bufferedReader.readLine()) != null)
response+= line;
bufferedReader.close();
inputStream.close();
httpURLConnection.disconnect();
return response;
catch (MalformedURLException e)
e.printStackTrace();
catch (IOException e)
e.printStackTrace();
return null;
@Override
protected void onProgressUpdate(Void... values)
super.onProgressUpdate(values);
//Server response
@Override
protected void onPostExecute(final String result)
//Toast toast =Toast.makeText(getApplicationContext(), result, Toast.LENGTH_LONG);
//toast.setGravity(Gravity.CENTER ,0,0);
//toast.show();
AlertDialog.Builder alert = new AlertDialog.Builder(context); // also i got crash here
alert.setTitle("Third Wheel Response");
alert.setMessage(result);
alert.setCancelable(false);
alert.setPositiveButton("ok", new DialogInterface.OnClickListener()
@Override
public void onClick(DialogInterface dialogInterface, int i)
dialogInterface.cancel();
);
AlertDialog dialogs = alert.create();
dialogs.show();
if (progressDialog != null)
progressDialog.dismiss();
SaveData.setEnabled(true);
错误：
11-10 08:40:23.174 4815-4815/com.thethirdwheelproject.thirdwheel E/androidRuntime: FATAL EXCEPTION: main 进程：com.thethirdwheelproject.thirdwheel，PID：4815 android.view.WindowManager$BadTokenException: 无法添加窗口——令牌android.os.BinderProxy@bc0afcf 无效；您的活动正在运行吗？ 在 android.view.ViewRootImpl.setView(ViewRootImpl.java:678) 在 android.view.WindowManagerGlobal.addView(WindowManagerGlobal.java:342) 在 android.view.WindowManagerImpl.addView(WindowManagerImpl.java:93) 在 android.app.Dialog.show(Dialog.java:316) 在 com.thethirdwheelproject.thirdwheel.MainActivity$BackgroundTask.onPostExecute(MainActivity.java:489) 在 com.thethirdwheelproject.thirdwheel.MainActivity$BackgroundTask.onPostExecute(MainActivity.java:389) 在 android.os.AsyncTask.finish(AsyncTask.java:660) 在 android.os.AsyncTask.-wrap1(AsyncTask.java) 在 android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:677) 在 android.os.Handler.dispatchMessage(Handler.java:102) 在 android.os.Looper.loop(Looper.java:154) 在 android.app.ActivityThread.main(ActivityThread.java:6077) 在 java.lang.reflect.Method.invoke（本机方法） 在 com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:866) 在 com.android.internal.os.ZygoteInit.main(ZygoteInit.java:756) 11-10 08:40:23.733 1334-1334/? E/EGL_emulation: tid 1334: eglCreateSyncKHR(1901): 错误 0x3004 (EGL_BAD_ATTRIBUTE)
【问题讨论】：
发布您的错误日志 你的上下文变量为空！！ 【参考方案1】：您的上下文变量未初始化
删除您的context 变量并改用MainActivity.this。
试试这个方法
@Override
public void onClick(View view)
view.setEnabled(false);
tvscancontent = tvScanContent.getText().toString();
tvscanformat = tvScanFormat.getText().toString();
BackgroundTask backgroundTask = new BackgroundTask();
backgroundTask.execute(tvscancontent,tvscanformat);
showShowView2();
// displaynotification();
);
【讨论】：
我仍然得到这个错误先生 private class BackgroundTask extends AsyncTask在构造函数中设置上下文， 像下面的东西
public BackgroundTask(Context context)
this.context = context;
【讨论】：
你是如何将上下文传递给你的 AsyncTask 类的？ 我只是在我的 AsyncTask 类先生中分配上下文变量 但我将上下文更改为 MainActivity.this，代码有效。所以你可能有其他错误导致这种情况。发布你的错误日志和代码你如何执行你的 asynctask 类。 android.os.BinderProxy@bc0afcf 无效；您的活动正在运行吗？ MainActivity 完成了？？？你可以检查你的代码如何以及何时调用你的 asynctask，或者你在调用 asynctask 时是否完成 MainActivity？ 看看我的更新帖子先生，我已经发布了我如何调用我的 AsyncTask 希望您能帮助我，谢谢先生【参考方案3】： //Calling my AsyncTask
@Override
public void onClick(View view)
view.setEnabled(false);
tvscancontent = tvScanContent.getText().toString();
tvscanformat = tvScanFormat.getText().toString();
BackgroundTask backgroundTask =new BackgroundTask();
backgroundTask.execute(tvscancontent,tvscanformat);
showShowView2();
// displaynotification();
);
//将数据插入数据库进程 私有类 BackgroundTask 扩展 AsyncTask
String add_info_url;
public BackgroundTask()
@Override
protected void onPreExecute()
add_info_url = "http://www.d48.asia/shan/index.php";
progressDialog = new ProgressDialog(MainActivity.this);
progressDialog.setTitle("Authentication Process");
progressDialog.setMessage("Loading....");
progressDialog.setCancelable(false);
progressDialog.setIndeterminate(true);
progressDialog.setProgressStyle(progressDialog.STYLE_SPINNER);
progressDialog.show();
@Override
protected String doInBackground(String... args)
String tvscancontent = args[0];
String tvscanformat = args[1];
String response = "";
String line = "";
try
URL url = new URL(add_info_url);
HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
httpURLConnection.setRequestMethod("POST");
httpURLConnection.setDoOutput(true);
httpURLConnection.setDoInput(true);
OutputStream outputStream = httpURLConnection.getOutputStream();
BufferedWriter bufferedWriter = new BufferedWriter(new OutputStreamWriter(outputStream, "UTF-8"));
String data_string = URLEncoder.encode("tvscancontent", "UTF-8") + "=" + URLEncoder.encode(tvscancontent, "UTF-8")+ "&" +
URLEncoder.encode("tvscanformat", "UTF-8") + "=" + URLEncoder.encode(tvscanformat, "UTF-8");
bufferedWriter.write(data_string);
bufferedWriter.flush();
bufferedWriter.close();
outputStream.close();
InputStream inputStream = httpURLConnection.getInputStream();
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream,"iso-8859-1"));
while ((line = bufferedReader.readLine()) != null)
response+= line;
bufferedReader.close();
inputStream.close();
httpURLConnection.disconnect();
return response;
catch (MalformedURLException e)
e.printStackTrace();
catch (IOException e)
e.printStackTrace();
return null;
@Override
protected void onProgressUpdate(Void... values)
super.onProgressUpdate(values);
@Override
protected void onPostExecute(final String result)
super.onPostExecute(result);
alert = new AlertDialog.Builder(MainActivity.this);
alert.setTitle(" Third Wheel Response");
alert.setMessage(result);
alert.setCancelable(false);
alert.setPositiveButton("Thanks", new DialogInterface.OnClickListener()
@Override
public void onClick(DialogInterface dialogInterface, int i)
Intent launchactivity = new Intent(MainActivity.this,MainActivity.class);
startActivity(launchactivity);
);
AlertDialog dialogs = alert.create();
dialogs.show();
if (progressDialog != null)
progressDialog.dismiss();
SaveData.setEnabled(true);
【讨论】：
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