我想在关闭应用程序时运行backgroundtask，而我想在用户关闭应用程序时运行logout.php
这是我的登录代码以及我如何运行Backgroundtask，我正在使用 ECLIPSE
很抱歉我的新手问题，我只是想学习Android，请帮助我
AlertDialog alertDialog;
Context ctx;
ProgressDialog nDialog;
String JSON_STRING;
String json_string;
private class BackgroundTask extends AsyncTask<String, Void, String> {
String JSON_URL;
String un,up;
@Override
protected void onPreExecute() {
JSON_URL ="https://ralph-rojas1996.000webhostapp.com/android/login1.php";
}
@Override
protected String doInBackground(String... args) {
un = args[0];
up = args[1];
try {
StringBuilder JSON_DATA = new StringBuilder();
URL url = new URL(JSON_URL);
HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
httpURLConnection.setRequestMethod("POST");
httpURLConnection.setDoOutput(true);
OutputStream outputStream = httpURLConnection.getOutputStream();
BufferedWriter bufferedWriter = new BufferedWriter(new OutputStreamWriter(outputStream,"UTF-8"));
String data_string = URLEncoder.encode("login_name","UTF-8")+"="+URLEncoder.encode(un,"UTF-8")+"&"+
URLEncoder.encode("login_pass","UTF-8")+"="+URLEncoder.encode(up,"UTF-8");
bufferedWriter.write(data_string);
bufferedWriter.flush();
bufferedWriter.close();
outputStream.close();
InputStream in = httpURLConnection.getInputStream();
BufferedReader reader = new BufferedReader(new InputStreamReader(in));
while ((JSON_STRING = reader.readLine())!=null) {
JSON_DATA.append(JSON_STRING).append("\n");
}
String x = JSON_DATA.toString().trim();
if(x.equals("1"))
{
return null;
}
else if(x.equals("2"))
{
la = "2";
return la;
}
else
{
return JSON_DATA.toString().trim();
}
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
@Override
protected void onProgressUpdate(Void... values) {
super.onProgressUpdate(values);
}
@Override
protected void onPostExecute(String result) {
json_string = result;
onLoginResponse(json_string);
}
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
getActionBar().hide();
setContentView(R.layout.activity_main);
B1 = (Button)findViewById(R.id.btnloginok);
t1 = (TextView)findViewById(R.id.name);
t2 = (TextView)findViewById(R.id.pname);
//new BackgroundTask().execute();
ConnectivityManager connectivityManager = (ConnectivityManager)getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo networkInfo = connectivityManager.getActiveNetworkInfo();
if(networkInfo!=null && networkInfo.isConnected())
{
t2.setVisibility(View.INVISIBLE);
t1.setVisibility(View.VISIBLE);
}
else
{
B1.setEnabled(false);
t2.setVisibility(View.VISIBLE);
t1.setVisibility(View.INVISIBLE);
}
un = (EditText)findViewById(R.id.editText1);
pass = (EditText)findViewById(R.id.editText2);
}
public void login(View v)
{
String uname = un.getText().toString();
String upass = pass.getText().toString();
BackgroundTask backgroundTask = new BackgroundTask();
backgroundTask.execute(uname,upass);
nDialog = new ProgressDialog(this);
nDialog.setMessage("Loading..");
nDialog.setTitle("Get Data");
nDialog.setIndeterminate(false);
nDialog.setCancelable(true);
nDialog.show();
/*final Handler handler = new Handler();
handler.postDelayed(new Runnable() {
@Override
public void run() {
// Do something after 5s = 5000ms
if(json_string==null)
{
Toast.makeText(getApplicationContext(), "Login Failed Try Again..", Toast.LENGTH_LONG).show();
}
else
{
//Toast.makeText(getApplicationContext(), json_string, Toast.LENGTH_LONG).show();
Intent intent = new Intent(MainActivity.this,intro.class);
intent.putExtra("json_data", json_string);
startActivity(intent);
}
}
}, 4000);*/
}
private void onLoginResponse(String json){
if(json==null)
{
nDialog.dismiss();
Toast.makeText(getApplicationContext(), "Login Failed Try Again..", Toast.LENGTH_LONG).show();
}
else if (json=="2")
{
nDialog.dismiss();
Toast.makeText(getApplicationContext(), "User is Already Logged In on other Device", Toast.LENGTH_LONG).show();
}
else
{
nDialog.dismiss();
//Toast.makeText(getApplicationContext(), json_string, Toast.LENGTH_LONG).show();
Intent intent = new Intent(MainActivity.this,intro.class);
intent.putExtra("json_page1", json);
startActivity(intent);
}
}
public void signup (View v)
{
Intent i = new Intent (this,signup.class);
startActivity(i);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}
我想在用户关闭应用程序时自动运行logout.php。