How to print variable from another class

Question

I need to print to variable voltage and current in my TextView in onCreate() method. Current and Voltage variables are in the clientgetui() method.

Here is my code:

import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.util.Arrays;

public class getUI extends AppCompatActivity {

    String IP;
    TextView txtCurrent, textVoltage;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_get_ui);

         IP = getIntent().getExtras().getString("IP");





       TextView txtCurrent = (TextView) findViewById(R.id.textViewCurrent);
       TextView textVoltage = (TextView) findViewById(R.id.textViewVoltage);

       // txtCurrent.setText(String.valueOf(current));

        Button buttongetvalue = (Button) findViewById(R.id.buttongetUI);
        buttongetvalue.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                try{
                    new AsynctaskgetUI().execute();
                }catch (Exception e){

                }


            }
        });


    } //ONCREATE!



        public class AsynctaskgetUI extends AsyncTask<Void, Integer, Void> {


            public int mVoltage;
            public int mCurrent;

            @Override
            protected void onPreExecute() {
                super.onPreExecute();
            }

            @Override
            protected void onPostExecute(Void aVoid) {
                super.onPostExecute(aVoid);
            }

            @Override
            protected void onProgressUpdate(Integer... values) {
                super.onProgressUpdate(values);

            }

            @Override
            protected Void doInBackground(Void... voids) {
                try {
                    clientgetui();
                } catch (IOException e) {
                    e.printStackTrace();
                };

                return null;
            }

                //____________________CLIENT1_____________________________

                public void clientgetui() throws IOException {

                    DatagramSocket ds = new DatagramSocket();
                    byte b[] = new byte[]{0x7F, 0x03, 0x01, 0x00, 0x01, 0x15, 0x00, 0x00, 0x00, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x20, 0x10, 0x00, 0x00, 0x00, 0x00};


                    // byte[] ipA = new byte[]{(byte) 192, (byte) 168, 1, (byte) 100};
                    // IPAdress = String.valueOf(getIntent().getExtras().getByte("IP insert"));


                    // String ipA = IP;

                    InetAddress ia = InetAddress.getByName(IP);

                    DatagramPacket dp = new DatagramPacket(b, 28, ia, 21234);
                    ds.send(dp);

                    byte buffer[] = new byte[28];
                    DatagramPacket reply = new DatagramPacket(buffer, buffer.length);


                    ds.receive(reply);

                    ds.close();

                    byte[] dp23 = Arrays.copyOfRange(buffer, 8, 12);

                    int voltage = (dp23[0] * 256 + dp23[1]) & 0xFF; // PRINT VOLTAGE
                    int current = (dp23[2] * 256 + dp23[3]) & 0xFF; // PRINT CURRENT in TextView


                }



            }

        }

https://developer.android.com/reference/android/os/AsyncTask.html — Arun Shankar, Apr 21 '17 at 07:53
Possible duplicate of [How to get the result of OnPostExecute() to main activity because AsyncTask is a separate class?](http://stackoverflow.com/questions/12575068/how-to-get-the-result-of-onpostexecute-to-main-activity-because-asynctask-is-a) — pringi, Apr 21 '17 at 09:07

score 0 · Accepted Answer · answered Apr 21 '17 at 07:56

0

As you are using AsyncTask

All the UI's data binding is done in onPostExecute method.

 @Override
        protected void onPostExecute(Void aVoid) {
            super.onPostExecute(aVoid);
            txtCurrent.setText(String.valueof(current));
            txtVoltage.setText(String.valueof(voltage));
        }

answered Apr 21 '17 at 07:56

garry

419
5
10

Thanks for your answer, but it reading current and voltage variables in the beginning of the code. it doesn't reading from my method – TLDima Apr 21 '17 at 08:43

score -1 · Answer 2 · answered Apr 21 '17 at 07:42

As i am seeing that you are calling clientgetui() method in background of a AsynTask so there are some various ways to get data.

Way1:

create global variables (voltage, current) and then before getting the value from these variables you should check that your AsynctaskgetUI has been completed or not.

Way2:

Save these variables in SharedPreferences and before getting data from sharedpreferences make sure that Your AsynctaskgetUI has been completed.

Way3:

Make global static variables and follow Way1.

from these above ways: from Way1 you can get the data from variables with in class while from other two ways you can get the data from variables outside class also.

Thanks for you answer. I will try it – TLDima Apr 21 '17 at 07:48 — TLDima, Apr 21 '17 at 07:48
Welcome if u face any problem comment will be appreciable. – singh.indolia Apr 21 '17 at 07:49 — singh.indolia, Apr 21 '17 at 07:49

How to print variable from another class

2 Answers2