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App crashes when you click several times

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By User



In my app the first screen is a list and when you click once it goes ok but if,my mistake or something, you click two or more times before it loads the application crashes. I've been doing a little research but I didn't found anything. I post my code:







@Override

public void onCreate(Bundle icicle) {

    super.onCreate(icicle);

    requestWindowFeature(Window.FEATURE_CUSTOM_TITLE);

    setContentView(R.layout.firstscreen);

    // Set title

    getWindow().setFeatureInt(Window.FEATURE_CUSTOM_TITLE,

            R.layout.mainheader);



    // Get Arguments

    Bundle extras = getIntent().getExtras();

    if (extras != null) {

        app = extras.getString("app");

    }



    //Set simulation date   

    TextView date = (TextView) findViewById(R.id.date);

    date.setText(convertDateToString());

    // set the list adapter: ListView myList =

    ListView lv = (ListView) findViewById(R.id.list);

    DataBaseAccess ddbb = new DataBaseAccess();

    //Download the data from a database

    lv.setAdapter(new MyAdapter(this, R.layout.listitem, myLines,

            flowAlarm, precAlarm));

    lv.setTextFilterEnabled(true);

    lv.setOnItemClickListener(new OnItemClickListener() {



        public void onItemClick(AdapterView<?> parent, View view,

                int position, long id) {

            Intent i = new Intent(Main.this, ShowGraph.class);

            String[] obj = list.split(";");

            i.putExtra("object name", obj[position]);

            i.putExtra("app name", app);

            i.putExtra("app list", list);

            startActivity(i);



        }

    });



    // Set buttons clickable

    Button exit = (Button) findViewById(R.id.exit);

    exit.setOnClickListener(this);

    Button calendar = (Button) findViewById(R.id.calendar);

    calendar.setOnClickListener(this);

}







Does anyone knows why?





My LogCat:







02-29 13:51:27.975: E/AndroidRuntime(9082): FATAL EXCEPTION: main

02-29 13:51:27.975: E/AndroidRuntime(9082): java.lang.NullPointerException

02-29 13:51:27.975: E/AndroidRuntime(9082):at org.achartengine.chart.XYChart.toRealPoint(XYChart.java:699)

02-29 13:51:27.975: E/AndroidRuntime(9082):at org.achartengine.tools.Pan.apply(Pan.java:64)

02-29 13:51:27.975: E/AndroidRuntime(9082):at org.achartengine.TouchHandler.handleTouch(TouchHandler.java:106)

02-29 13:51:27.975: E/AndroidRuntime(9082):at org.achartengine.GraphicalView.onTouchEvent(GraphicalView.java:284)

02-29 13:51:27.975: E/AndroidRuntime(9082):at android.view.View.dispatchTouchEvent(View.java:3952)

02-29 13:51:27.975: E/AndroidRuntime(9082):at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1034)

02-29 13:51:27.975: E/AndroidRuntime(9082):at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1034)

02-29 13:51:27.975: E/AndroidRuntime(9082):at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1034)

02-29 13:51:27.975: E/AndroidRuntime(9082):at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1034)

02-29 13:51:27.975: E/AndroidRuntime(9082):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1034)

02-29 13:51:27.975: E/AndroidRuntime(9082):     at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:1034)

02-29 13:51:27.975: E/AndroidRuntime(9082):     at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:1711)

02-29 13:51:27.975: E/AndroidRuntime(9082):     at com.android.internal.policy.impl.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1145)

02-29 13:51:27.975: E/AndroidRuntime(9082):     at android.app.Activity.dispatchTouchEvent(Activity.java:2096)

02-29 13:51:27.975: E/AndroidRuntime(9082):at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:1695)

02-29 13:51:27.975: E/AndroidRuntime(9082):at android.view.ViewRoot.deliverPointerEvent(ViewRoot.java:2217)

02-29 13:51:27.975: E/AndroidRuntime(9082):at android.view.ViewRoot.handleMessage(ViewRoot.java:1901)

02-29 13:51:27.975: E/AndroidRuntime(9082):at android.os.Handler.dispatchMessage(Handler.java:99)

02-29 13:51:27.975: E/AndroidRuntime(9082):at android.os.Looper.loop(Looper.java:130)

02-29 13:51:27.975: E/AndroidRuntime(9082):at android.app.ActivityThread.main(ActivityThread.java:3701)

02-29 13:51:27.975: E/AndroidRuntime(9082):at java.lang.reflect.Method.invokeNative(Native Method)

02-29 13:51:27.975: E/AndroidRuntime(9082):at java.lang.reflect.Method.invoke(Method.java:507)

02-29 13:51:27.975: E/AndroidRuntime(9082):at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:866)

02-29 13:51:27.975: E/AndroidRuntime(9082):at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:624)

02-29 13:51:27.975: E/AndroidRuntime(9082):at dalvik.system.NativeStart.main(Native Method)







The ShowGraph activity oncreate:







@Override

public void onCreate(Bundle savedInstanceState) {



    super.onCreate(savedInstanceState);



    // Get arguments

    Bundle extras = getIntent().getExtras();

    if (extras != null) {

        object = extras.getString("object name");

        app = extras.getString("app name");

        list = extras.getString("app list");

    }

    // Set title

    requestWindowFeature(Window.FEATURE_CUSTOM_TITLE);

    setContentView(R.layout.main);

    getWindow().setFeatureInt(Window.FEATURE_CUSTOM_TITLE,

            R.layout.headermenu);

    // Download the info from the database



     downloadInfo(app, object);



    // set the button listeners

    listeners();

    //Set checkbox listeners

    setCheckListeners();



    // Drag Meteo

    vg = (RelativeLayout) findViewById(R.id.graph);

    vg.setOnTouchListener(new View.OnTouchListener() {

        RelativeLayout vg1 = (RelativeLayout) findViewById(R.id.graph1);



        public boolean onTouch(View v, MotionEvent event) {

            switch (event.getAction()) {

            case MotionEvent.ACTION_MOVE:

                // int x = (int) event.getX() - offset_x;

                int y = (int) event.getY() - offset_y;

                int w = getWindowManager().getDefaultDisplay().getWidth();

                int h = vg.getHeight() - 40;

                if (y < 0)

                    y = 0;

                if (y > h)

                    y = h;

                RelativeLayout.LayoutParams lp = new RelativeLayout.LayoutParams(

                        new ViewGroup.MarginLayoutParams(

                                RelativeLayout.LayoutParams.FILL_PARENT,

                                RelativeLayout.LayoutParams.WRAP_CONTENT));

                lp.setMargins(0, y, 0, 0);

                selected_item.setLayoutParams(lp);

                int height = vg1.getHeight();

                RelativeLayout.LayoutParams lp2 = new RelativeLayout.LayoutParams(

                        new ViewGroup.MarginLayoutParams(

                                RelativeLayout.LayoutParams.FILL_PARENT,

                                RelativeLayout.LayoutParams.WRAP_CONTENT));

                lp2.setMargins(0, 0, 0, Math.abs(vg.getHeight() - y));

                // lp2.height = y-height;

                vg1.setLayoutParams(lp2);

                break;

            default:

                break;

            }

            return true;

        }

    });

    RelativeLayout img = (RelativeLayout) findViewById(R.id.vg);

    img.setOnTouchListener(new View.OnTouchListener() {



        public boolean onTouch(View v, MotionEvent event) {

            switch (event.getAction()) {

            case MotionEvent.ACTION_DOWN:

                offset_x = (int) event.getX();

                offset_y = (int) event.getY();

                selected_item = v;

                break;

            default:

                break;

            }

            return false;

        }

    });

}







I tried with the AsyncTask as I read here but is not working:





Android: Disable ListView once clicked?


Labels:

Comments

  1. Tips For AllMarch 1, 2012 at 9:32 AM

    In ShowGraph:

    if (extras != null) {
    object = extras.getString("object name");
    app = extras.getString("app name");
    list = extras.getString("app list");
    }


    If your extras is null, then your app is null too. So problem can be there

    downloadInfo(app, object); //NullPointerException


    ALSO

    1) Note that onCreate() called once (only for first click). It's better to move your "get Intent" part to onStart() method.

    2) Use debbuging tools or try to hide your code with comments block by block, to find where is NullPointerException exactly.

    /*Like this
    downloadInfo(app, object);
    */

    ReplyDelete

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