How to free Memory in my android application

Good days

I'm already in the process of testing my android application, and I have a question what happens is that being doing several movements, the app freezes and gets a little slow, what I see is by memory detail of my app, is not releasing it, someone could tell me how the memory is released in an android app.

Thank you.

As I told you, the problem I have in my last screen is where the user has to generate charges .. right now I have already put a method to delete the cache of my application ... I leave the code of the activity where I have the problem and the screen ...

Activity detail

public class Detail_Client extends AppCompatActivity {

// Controls     public Button pay;     public Button Pagoc;

//Dialogos
ProgressDialog dialog;
AlertDialog alert = null;

//Array Detalle
ListView list;
ArrayList<DetalleCxP> DetalleArrayList = new ArrayList<DetalleCxP>();
MyArrayAdapter adaptador;

CXCPSaldoClienteProveedor O_Cliente;
DetalleMenu O_DetalleMenu;
Integer I_FormaPago=0;


//Manejo de Intent
public Bundle extras;
public Intent intent;
public String UsuarioCap;

//Ubicacion GPS
LocationManager locManager;
LocationListener locListener;


final Context context = this;
public String obser;
private static final String TAG = "mx.com.oncontrol.oncontrolmovile";

//Forma de Pago
public TextView formap;

//Array Forma de Pago
ArrayList<FormaPago> PagoArrayList = new ArrayList<FormaPago>();


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_detalle__cliente);
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);

    //Manejo de Intent
    extras = getIntent().getExtras();
    UsuarioCap = extras.getString("UsuarioCaptura2");
    intent = getIntent();
    O_DetalleMenu=(DetalleMenu) intent.getSerializableExtra("O_DetalleMenu");
    intent=getIntent();
    O_Cliente=(CXCPSaldoClienteProveedor) intent.getSerializableExtra("O_Cliente");
    setTitle(O_Cliente.getClienteDescripcion());

    //codigo listview
    list=(ListView)this.findViewById(R.id.listDeta);
    AsyncCallWSDetalle task = new AsyncCallWSDetalle();
    //Call execute
    task.execute();
    comenzarLocalizacion();

   pagar = (Button)this.findViewById(R.id.btnpago);
    pagar.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v)
        {
            AlertDialog.Builder alert = new AlertDialog.Builder(Detalle_Cliente.this);
            alert.setMessage("¿Estas Seguro de Aplicar el Abono?");
            alert.setTitle("Confirmacion");

            alert.setPositiveButton("Aceptar", new DialogInterface.OnClickListener()  {
                public void onClick(DialogInterface dialog, int id) {
                    I_FormaPago=((FormaPago)((Spinner)findViewById(R.id.menu_spinner1)).getSelectedItem()).getId();

                    comenzarLocalizacion();
                    AsyncGrabarCXCP task = new AsyncGrabarCXCP();


                    //Call execute
                    task.execute();
                }
            });
            alert.setNegativeButton("Cancelar", new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int id) {
                    dialog.cancel();
                }
            });
            alert.show();
        }
    });


    Pagoc = (Button)this.findViewById(R.id.btn_pagoceros);
    Pagoc.setOnClickListener(new View.OnClickListener() {
        @TargetApi(Build.VERSION_CODES.LOLLIPOP)
        @Override
        public void onClick(View v)
        {
            LayoutInflater li = LayoutInflater.from(context);
            View pron = li.inflate(R.layout.row_dialog, null);

            AlertDialog.Builder alert = new AlertDialog.Builder(context);
            alert.setTitle("Confirmacion de Pago en 0!");
            alert.setMessage("Favor Ingresa el Motivo Por el " +
                              "cual no se realizo el Pago");
            alert.setView(pron);
            final EditText observ = (EditText)pron.findViewById(R.id.edtobser);
            obser = observ.getText().toString();
            alert.setCancelable(false);
            alert.setPositiveButton("Aceptar", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                comenzarLocalizacion();
                AsyncGrabarCXCP task = new AsyncGrabarCXCP();
                obser = observ.getText().toString();
                //Call execute
                task.execute();
            }
        });
            alert.setNegativeButton("Cancelar", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                       dialog.cancel();
                }
            });
            alert.show();
        }
    });

}
//Codigo de Buscador en la parte del ActionBar
@Override
public boolean onCreateOptionsMenu(android.view.Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.menu_detalle, menu);
    MenuItem item = menu.findItem(R.id.menu_spinner1);
    Spinner spinner = (Spinner) MenuItemCompat.getActionView(item);

    //Se manda a llamar el metodo del spinner
    AsyncForma task = new AsyncForma();
    //Call execute
    task.execute();
    return true;

}

@Override
public boolean onOptionsItemSelected(MenuItem item) {

    int id = item.getItemId();

    //noinspection SimplifiableIfStatement
    if (id == R.id.action_settings) {
        return true;
    }

    return super.onOptionsItemSelected(item);
}



private void comenzarLocalizacion() {
    //Obtenemos una referencia al LocationManager
    locManager =
            (LocationManager) getSystemService(Context.LOCATION_SERVICE);

    //Obtenemos la última posición conocida
    Location loc = locManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);

    if(loc != null)
    {
        O_Cliente.setGPSLocation("http://maps.google.com/maps?q=" + String.valueOf(loc.getLatitude() + ",+" + String.valueOf(loc.getLongitude())));
    }


    //Nos registramos para recibir actualizaciones de la posición
    locListener = new LocationListener() {


        public void onLocationChanged(Location location) {
            if(location.getLatitude() != 0.0D && location.getLongitude() != 0.0D) {
                try {
                    Geocoder e = new Geocoder(Detalle_Cliente.this, Locale.getDefault());
                    List list = e.getFromLocation(location.getLatitude(), location.getLongitude(), 1);
                    if(!list.isEmpty()) {
                        Address DirCalle = (Address)list.get(0);
                        //direccion.setText("Mi direccion es: \n" + DirCalle.getAddressLine(0));
                        O_Cliente.setGPSLocation2(DirCalle.getAddressLine(0));
                    }
                } catch (IOException var5) {
                    var5.printStackTrace();
                }
            }

        }

        public void onProviderDisabled(String provider) {
            //lblEstado.setText("Provider OFF");
        }

        public void onProviderEnabled(String provider) {
            //lblEstado.setText("Provider ON ");
        }

        public void onStatusChanged(String provider, int status, Bundle extras) {
            /*Log.i("", "Provider Status: " + status);
            lblEstado.setText("Provider Status: " + status);*/
        }
    };

    if (ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
        // TODO: Consider calling
        //    ActivityCompat#requestPermissions
        // here to request the missing permissions, and then overriding
        //   public void onRequestPermissionsResult(int requestCode, String[] permissions,
        //                                          int[] grantResults)
        // to handle the case where the user grants the permission. See the documentation
        // for ActivityCompat#requestPermissions for more details.
        return;
    }
    locManager.requestLocationUpdates(
            LocationManager.GPS_PROVIDER, 1000, 0, locListener);
}


private class AsyncCallWSDetalle extends AsyncTask<String, ArrayList, ArrayList> {


    @Override
    protected ArrayList doInBackground(String... params){
        DetalleArrayList=webService.DetalleCxP(O_Cliente.getCliente(), O_DetalleMenu.getDocumento());
        return null;

    }

    @Override
    //Make Progress Bar visible
    protected void onPreExecute() {

        dialog=new ProgressDialog(Detalle_Cliente.this);
        dialog.setIndeterminate(false);
        dialog.setMessage("Cargando Detalle...");
        dialog.setCancelable(false);
        dialog.show();

    }

    //Once WebService returns response
    @Override
    protected void onPostExecute(ArrayList arrayList) {
        super.onPostExecute(arrayList);
        if(DetalleArrayList.size()!=0){
            dialog.dismiss();

            adaptador= new MyArrayAdapter(Detalle_Cliente.this, DetalleArrayList);///* no se usa your_array_list

            list = (ListView) findViewById(R.id.listDeta);
            list.setAdapter(adaptador);
            adaptador.notifyDataSetChanged();


        }else{
            dialog.dismiss();
        }
    }
}




public class MyArrayAdapter extends ArrayAdapter<DetalleCxP> {


    public MyArrayAdapter(Context context, ArrayList<DetalleCxP> ArrayClientes) {
        super(context, 0, ArrayClientes);
    }

    public View getView(int position, View convertView, ViewGroup parent) {

        DetalleCxP O_DetalleCxP = getItem(position);

        // Check if an existing view is being reused, otherwise inflate the view
        if (convertView == null)
        {
            convertView = LayoutInflater.from(getContext()).inflate(R.layout.row_detalle, parent, false);
            //Abono = (EditText) convertView.findViewById(R.id.edt_abono);
            //attach the TextWatcher listener to the EditText
            ((EditText) convertView.findViewById(R.id.edt_abono)).addTextChangedListener(new TB_Abono_Watcher(convertView));
        }

        //Obteniendo instancias de los text views
        /*
        vencido = (TextView)convertView.findViewById(R.id.txtvencido);
        saldo = (TextView)convertView.findViewById(R.id.txttotal);
        Abono = (EditText) convertView.findViewById(R.id.edt_abono);
        total = (TextView)convertView.findViewById(R.id.total);

* /

        DecimalFormat numberFormat  = new DecimalFormat("###,##0.00");

        SimpleDateFormat dateFormat = new SimpleDateFormat("dd/MM/yyyy");



        ((TextView)convertView.findViewById(R.id.txtFecha)).setText(dateFormat.format(O_DetalleCxP.getFecha()));


        ((TextView)convertView.findViewById(R.id.txtFolio)).setText(O_DetalleCxP.getFolio());

        ((EditText) convertView.findViewById(R.id.edt_abono)).setTag(O_DetalleCxP);
        if (O_DetalleCxP.TotalAplicado>0)
        {
            ((EditText) convertView.findViewById(R.id.edt_abono)).setText(numberFormat.format(O_DetalleCxP.TotalAplicado));
        }
        else
        {
            ((EditText) convertView.findViewById(R.id.edt_abono)).setText("");
        }

        ((TextView)convertView.findViewById(R.id.total)).setText(numberFormat.format(O_DetalleCxP.getTotal()));
        ((TextView)convertView.findViewById(R.id.txttotal)).setText(numberFormat.format(O_DetalleCxP.getSaldo()));
        ((TextView)convertView.findViewById(R.id.txtvencido)).setText(numberFormat.format(O_DetalleCxP.getSaldoVencido()));




        //Devolver al ListView la fila creada
        return convertView;

    }
}



//Clase para Edittext
private class TB_Abono_Watcher implements TextWatcher{


   Button pagar =(Button)findViewById(R.id.btnpago);
    private View view;
    private TB_Abono_Watcher(View view) {
        this.view = view;
    }

    public void beforeTextChanged(CharSequence s, int start, int count, int after) {

    }
    public void onTextChanged(CharSequence s, int start, int before, int count) {

        //do nothing
    }
    public void afterTextChanged(Editable s)
    {

        //Abono = (EditText)view.findViewById(R.id.edt_abono);
        DetalleCxP O_DetalleCxP = (DetalleCxP)((EditText)view.findViewById(R.id.edt_abono)).getTag();
        O_DetalleCxP.TotalAplicado=ONC_SYS.NullToZeroDouble(s.toString());

        Double Total=0.0;
        for(int i=0;i<DetalleArrayList.size();i++)
        {
            if (((DetalleCxP)DetalleArrayList.get(i)).TotalAplicado>0)
            {
                Total += ((DetalleCxP)DetalleArrayList.get(i)).TotalAplicado;
            }
        }
        DecimalFormat numberFormat  = new DecimalFormat("0.00");
        ((TextView)findViewById(R.id.txtTotal)).setText(numberFormat.format(Total));

        if (Total==0)
        {
            ((Button)findViewById(R.id.btn_pagoceros)).setEnabled(true);
            ((Button)findViewById(R.id.btnpago)).setEnabled(false);
        }
        else
        {
            ((Button)findViewById(R.id.btn_pagoceros)).setEnabled(false);
            ((Button)findViewById(R.id.btnpago)).setEnabled(true);
        }


        //Validacion que no te deje hacer un abono Mayo al saldo vencido
        if (O_DetalleCxP.getSaldo() < O_DetalleCxP.TotalAplicado)
        {
            Toast.makeText(getApplicationContext(),"No puedes Aplicar un Abono Mayor al SaldoVencido",Toast.LENGTH_SHORT).show();
            ((EditText)view.findViewById(R.id.edt_abono)).setText("");

        }
    }
}


//Medoto para Grabar datos

public class AsyncGrabarCXCP extends AsyncTask<Void,Integer,String>
{
    int Recurso;


    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        dialog=new ProgressDialog(Detalle_Cliente.this);
        dialog.setIndeterminate(false);
        dialog.setMessage("Procesando Datos...");
        dialog.setCancelable(false);
        dialog.show();
    }

    @Override
    protected String doInBackground(Void... params) {
        String Resultado="";

        Recurso=webService.ObtenerRecurso();
        String Folio = webService.ObtenerFolio(35);
        Date O_D = new Date();

        Double Factor=0.0, Importe=0.0, Descuento=0.0, SubTotal=0.0, Total=0.0, IVA=0.0,Retencion1=0.0,Retencion2=0.0,IEPS=0.0;

        Double DFactor=0.0;

        final int count = DetalleArrayList.size();

        for(int i=0;i<count;i++) {

            Factor=0.0;

            if (((DetalleCxP)DetalleArrayList.get(i)).TotalAplicado>0)
            {
                Factor = ((DetalleCxP)DetalleArrayList.get(i)).TotalAplicado / ((DetalleCxP)DetalleArrayList.get(i)).Total;

                Importe += ((DetalleCxP)DetalleArrayList.get(i)).Importe*Factor;
                Descuento += ((DetalleCxP)DetalleArrayList.get(i)).Descuento*Factor;
                SubTotal += ((DetalleCxP)DetalleArrayList.get(i)).SubTotal*Factor;
                IVA += ((DetalleCxP)DetalleArrayList.get(i)).IVA*Factor;
                Retencion1 += ((DetalleCxP)DetalleArrayList.get(i)).Retencion1*Factor;
                Retencion2 += ((DetalleCxP)DetalleArrayList.get(i)).Retencion2*Factor;
                IEPS += ((DetalleCxP)DetalleArrayList.get(i)).IEPS*Factor;
                Total += ((DetalleCxP)DetalleArrayList.get(i)).Total*Factor;
            }

        }


        Resultado = webService.LLenarEncabezadoCXCP(Recurso,
                "I",    //Accion I
                0,      //Id = 0
                O_Cliente.getEmpresa(), //Id de Empresa
                Folio,
                new Date(),
                O_Cliente.getCliente(),
                O_Cliente.getProveedor(),
                O_Cliente.getMoneda(),
                1.0,      //Tipo de Cambio por default 1
                0,      //Cuenta Bancaria
                UsuarioCap, //Usuario Captura
                I_FormaPago,          //Pago Forma
                Total,          //Saldo
                Importe,    //Importe
                0,          //Financiamiento
                Descuento,
                SubTotal,
                Retencion1,
                Retencion2,
                IEPS,
                IVA,
                0,          //ISH,
                Total,      //Total
                Total,      //totalaplicado,
                "A",        //status,
                "",         //usucariocancela,
                0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0,   //Numero1...Numero10
                O_Cliente.getGPSLocation(), //Texto1
                O_Cliente.getGPSLocation2(),  //Texto2
                "","","","","","","","",                      //Texto1...Texto10
                new Date(),new Date(),new Date(),new Date(),new Date(),new Date(),  //Fecha1...Texto6
                obser,         //Observacion
                0,0,0,0,0,0,         //Catalogo1...Catalogo6
                "",         //ordencompra
                0,          //concepto
                "",         //observacioncancelacion
                0,          //origenventacompra,
                0           //origeninventario
        );
        if (Resultado.equals("OK"))
        {

            for(int i=0;i<DetalleArrayList.size();i++) {



                if (((DetalleCxP)DetalleArrayList.get(i)).TotalAplicado>0)
                {
                    DFactor = ((DetalleCxP)DetalleArrayList.get(i)).TotalAplicado / ((DetalleCxP)DetalleArrayList.get(i)).Total;


                    Resultado = webService.LLenarDetalleCXCP(Recurso,
                            "I", //Accion
                            0, //id
                            ((DetalleCxP)DetalleArrayList.get(i)).getId(),  //Origen
                            ((DetalleCxP)DetalleArrayList.get(i)).getDocumento(),  //OrigenDocumento
                            (Double)(((DetalleCxP)DetalleArrayList.get(i)).Importe*DFactor),   //Importe
                            (Double)0.0,  //Financiamiento
                            (Double)(((DetalleCxP)DetalleArrayList.get(i)).Descuento*DFactor), //Descuento
                            (Double)(((DetalleCxP)DetalleArrayList.get(i)).SubTotal*DFactor),   //Subtotal
                            (Double)(((DetalleCxP)DetalleArrayList.get(i)).Retencion1*DFactor), //Retencion1
                            (Double)(((DetalleCxP)DetalleArrayList.get(i)).Retencion2*DFactor),  //Retencion2
                            (Double)(((DetalleCxP)DetalleArrayList.get(i)).IEPS*DFactor),   //IEPS
                            (Double)(((DetalleCxP)DetalleArrayList.get(i)).IVA*DFactor), //IVA
                            (Double)0.0, //ISH
                            (Double)(((DetalleCxP)DetalleArrayList.get(i)).Total*DFactor),  //Total
                            ((DetalleCxP)DetalleArrayList.get(i)).getSaldo(),   //Saldo
                            "Android App"      //Referencia
                    );

                }

            }

        }


        if (Resultado.equals("OK"))

        {

            Resultado = webService.GrabarCxCP(Recurso,//Recurso
                    O_DetalleMenu.getModulo(),      //Modulo
                    O_DetalleMenu.getOperacion(),      //Operacion
                    O_DetalleMenu.getDocumento(),      //Documento
                    0,      //OrigenId
                    0);     //OrigenDocumento
        }

        return Resultado;
    }

    @Override
    protected void onPostExecute(String Resultado) {
        super.onPostExecute(Resultado);
        if (Resultado.equals("LA OPERACION FUE REALIZADA CON EXITO"))
        {
            dialog.dismiss();
            Toast.makeText(getApplicationContext(), "Datos Guardado Correctamente", Toast.LENGTH_SHORT).show();
            finish();
            }else{
                dialog.dismiss();
                Toast.makeText(getApplicationContext(), "Error en el Webservices" , Toast.LENGTH_LONG).show();
            }
    }
}

public DetalleCxP FindCXCPSaldoClienteProveedorById(int Id)
{
    for(int i=0;i<DetalleArrayList.size();i++)
    {
        if (DetalleArrayList.get(i).getId()==Id)
        {
            return DetalleArrayList.get(i);
        }
    }
    return null;
}


private class AsyncForma extends AsyncTask<String, ArrayList, ArrayList>
{

    @Override
    protected ArrayList doInBackground(String... params) {
        PagoArrayList=webService.FormaPago();
        return null;
    }

    @Override
    protected void onPostExecute(ArrayList arrayList) {
        super.onPostExecute(arrayList);

        if(PagoArrayList.size()!=0){

            Spinner spinner = (Spinner)findViewById(R.id.menu_spinner1);
            ArrayAdapter<FormaPago> adapter = new ArrayAdapter<FormaPago>(context, android.R.layout.simple_spinner_dropdown_item, PagoArrayList);
            spinner.setAdapter(adapter);

        }else{

        }
    }
}



@TargetApi(Build.VERSION_CODES.JELLY_BEAN)
@SuppressLint("LongLogTag")
@Override
protected void onDestroy() {
    super.onDestroy();
    Log.i(TAG, "onDestroy");
   DetalleArrayList = null;
    list = null;
    adaptador = null;
    O_DetalleMenu = null;
    extras = null;
    intent = null;
    UsuarioCap = null;
    obser = null;
    PagoArrayList = null;
    deleteCache(context);
    System.gc();
}


public static void deleteCache(Context context) {
    try {
        File dir = context.getCacheDir();
        deleteDir(dir);
    } catch (Exception e) {}
}

public static boolean deleteDir(File dir) {
    if (dir != null && dir.isDirectory()) {
        String[] children = dir.list();
        for (int i = 0; i < children.length; i++) {
            boolean success = deleteDir(new File(dir, children[i]));
            if (!success) {
                return false;
            }
        }
        return dir.delete();
    }
    else if(dir!= null && dir.isFile())
        return dir.delete();
    else {
        return false;
    }
}

}