Question

I have a mainActivity which is Customer.java with listview of 5 diff. activities. I was able to open all 5 activities when I tap them but when i press back button(the device backbutton) to go back to the mainAcitivity it would give me an error which you will see debug/logcat below the codes. I have post 2 examples activity below my main screen (logout and clockin) .

Bonus: As one extra thing I would like to have is when click of the ‘clockinActivity’ button i want it to send the current time & date to webserver(I already have customhttp class within my project) and automatically go back to main screen.

I have read the

http://developer.android.com/reference/android/app/Activity.html#ActivityLifecycle

http://android-developers.blogspot.com/2009/12/back-and-other-hard-keys-three-stories.html

Also this one doesn’t seem to work

@Override
public boolean onKeyDown(int keyCode, KeyEvent event)
{
    if (keyCode == KeyEvent.KEYCODE_BACK)
    {
       //do smth
    }
    return super.onKeyDown(keyCode, event);
}

Customer.java

import android.app.ListActivity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.TextView;

public class Customer extends ListActivity
{
    TextView selection;
    CustomerListItem[] items = { 
            new CustomerListItem("Start Trip", StartTripActivity.class), 
            new CustomerListItem("Clock in", ClockinActivity.class), 
            new CustomerListItem("Customer Svc", CustomerSvcActivity.class), 
            new CustomerListItem("Independent Inspection", InspectionActivity.class), 
            new CustomerListItem("Pick Up", PickUpActivity.class), 
            new CustomerListItem("Log Out", LogoutActivity.class)};
    private TextView resultsTxt;

    @Override
    public void onCreate(Bundle icicle)
    {
        super.onCreate(icicle);
        setContentView(R.layout.main);
        setListAdapter(new ArrayAdapter<CustomerListItem>(
                this, android.R.layout.simple_list_item_1, items));
        selection = (TextView) findViewById(R.id.selection);
    }

    @Override
    protected void onListItemClick(ListView l, View v, int position, long id)
    {
        super.onListItemClick(l, v, position, id);
        final Intent intent = new Intent(this, items[position].getActivity());
        startActivityForResult(intent, position);
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent intent)
    {
        super.onActivityResult(requestCode, resultCode, intent);
        if (resultCode == RESULT_OK)
        {
            // Perform different actions based on from which activity is
            // the application returning:
            switch (requestCode)
            {
                case 0:
                    // TODO: handle the return of the StartTripActivity
                    break;
                case 1:
                    // TODO: handle the return of the ClockinActivity
                    break;
                case 2:
                    // TODO: handle the return of the CustomerSvcActivity
                case 3:
                    // TODO: handle the return of the InspectionActivity
                    break;
                case 4:
                    // TODO: handle the return of the PickUpActivity
                    break;
                case 5:
                    // TODO: handle the return of the LogoutActivity
                    break;
                default:
                    break;
            }
        }
        else if (resultCode == RESULT_CANCELED)
        {
            resultsTxt.setText("Canceled");
        }
    }
}

ClockinActivity.java

import java.util.Date;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;



public class ClockinActivity extends Activity {
    @Override
    public void onCreate(Bundle savedInstanceState) { 
        super.onCreate(savedInstanceState);
        setContentView(R.layout.clockin);
        Thread myThread = null;



        Runnable runnable = new CountDownRunner();
       myThread= new Thread(runnable);   
        myThread.start();

   }

   public void doWork() {

   runOnUiThread(new Runnable() {
       public void run() {
           try{
       TextView txtCurrentTime= (TextView)findViewById(R.id.lbltime);
                   Date dt = new Date();
                   int hours = dt.getHours();
                   int minutes = dt.getMinutes();
                   int seconds = dt.getSeconds();
                   String curTime = hours + ":"+ minutes + ":"+ seconds;
                   txtCurrentTime.setText(curTime);
       }catch (Exception e) {

       }
       }
   });

   }

   class CountDownRunner implements Runnable{
       // @Override
       public void run() {
               while(!Thread.currentThread().isInterrupted()){
                   try {
                   doWork();
                       Thread.sleep(1000);
                   } catch (InterruptedException e) {
                           Thread.currentThread().interrupt();
                   }catch(Exception e){
                   }
               }



Button btn = (Button) findViewById(R.id.btn_OK);

//---event handler for the OK button---
btn.setOnClickListener(new View.OnClickListener() 
{
    public void onClick(View view) {
        Intent data = new Intent();

        //---get the EditText view--- 
//        EditText txt_username = 
//            (EditText) findViewById(R.id.txt_username);

        //---set the data to pass back---
       // data.setData(Uri.parse(
           // txt_username.getText().toString()));                           
        setResult(RESULT_OK, data);

        //---closes the activity---
        finish(); 
    }
});  
}
}
}

Logout.java

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;



public class LogoutActivity extends Activity {
    private Button btnLogout;
    private Button btnCancel;
    private TextView lblResult;
    private EditText code;
    @Override
    public void onCreate(Bundle savedInstanceState) { 
        super.onCreate(savedInstanceState);
        setContentView(R.layout.logout);

        code = (EditText)findViewById(R.id.codeout);
        btnLogout = (Button) findViewById(R.id.submit);
        btnCancel = (Button) findViewById(R.id.cancel);
        lblResult = (TextView)findViewById(R.id.result);

        btnLogout.setOnClickListener(new OnClickListener(){

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                String logout = code.getText().toString();

                if (logout.equals("99999")){
                    lblResult.setText("Logout successful");

                    Intent i = new Intent(getApplicationContext(), Login.class);
                    startActivity(i);
                } else {
                    lblResult.setText("Logout failed");

                }
            }
        });

         btnCancel.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {

                Intent i = new Intent(getApplicationContext(), Customer.class);
                startActivity(i);

            }

    });


}}

LogCat

05-19 21:52:51.586: WARN/ActivityManager(58): Launch timeout has expired, giving up wake lock!
05-19 21:52:51.586: WARN/ActivityManager(58): Activity idle timeout for HistoryRecord{45108f08 com.merrill/.Customer}
05-19 21:52:56.799: WARN/ActivityManager(58): Activity destroy timeout for HistoryRecord{4510cf30 com.merrill/.Clockin}

Debug

ActivityThread.deliverResults(ActivityThread$ActivityRecord, List) line: 3515
ActivityThread.handleSendResult(ActivityThread$ResultData) line: 3557
ActivityThread.access$2800(ActivityThread, ActivityThread$ResultData) line: 125
ActivityThread$ResultData(ActivityThread$H).handleMessage(Message) line: 2063
ActivityThread$H(Handler).dispatchMessage(Message) line: 99
Looper.loop() line: 123
ActivityThread.main(String[]) line: 4627
Method.invokeNative(Object, Object[], Class, Class[], Class, int, boolean) line: not available [native method]
Method.invoke(Object, Object…) line: 521
ZygoteInit$MethodAndArgsCaller.run() line: 868
ZygoteInit.main(String[]) line: 626
NativeStart.main(String[]) line: not available [native method]

Answer 1

I found the answer by using the code below. I had to put that code before the onCreate the errors I’ve been having was putting that code after the onCreate. It seems to work for me unless anyone else got better suggestions. Even though both code works, I prefer the first one as it would kill the current activity ‘finish()’ and return to the previous screen and the second code it will start the activity and keep both activity in the stack.

@Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        if (keyCode == KeyEvent.KEYCODE_BACK) {
            Pop("Back Button");
            Intent intent = new Intent();
            setResult(RESULT_OK, intent);
            finish();
            return true;
        }
        return super.onKeyDown(keyCode, event);
    }

or

@Override  
    public boolean onKeyDown(int keyCode, KeyEvent event)  
    {  
        //replaces the default 'Back' button action  
        if(keyCode==KeyEvent.KEYCODE_BACK)  
        {  
            //do whatever you want the 'Back' button to do  
            //as an example the 'Back' button is set to start a new Activity named 'NewActivity'  
            this.startActivity(new Intent(thisActivity.this,nextActivity.class));  
        }  
        return true;  
    }