Question

Hi im new to android programming and this code produces an error when the button is clicked… It shows unfortunately the application has stopped can anybody check? 🙁

protected void onCreate(Bundle savedInstanceState)
{
    super.onCreate(savedInstanceState);
    setContentView(R.layout.compute);
    aButton = (Button) this.findViewById(R.id.Button06);

    //get intent
    Intent i = getIntent();
    Bundle extras = i.getExtras(); // get the parameters

    density = getBaseContext().getResources().getDisplayMetrics().density;
    int textViewSizeDp = (int)(200 * density);
    int textFieldSizeDp = (int)(50 * density);

    FieldsLayout = (LinearLayout) findViewById(R.id.FieldsLayout);
    if(extras!=null){
        items = (extras.getString("items")).split(",");
        rows = new LinearLayout[items.length];
        labels = new TextView[items.length];
        fields = new EditText[items.length];

        for (int ctr=0;ctr<items.length;ctr++){
            rows[ctr] = new LinearLayout(Compute.this);
            rows[ctr].setGravity(Gravity.CENTER_VERTICAL | Gravity.CENTER_HORIZONTAL);
            rows[ctr].setOrientation(LinearLayout.HORIZONTAL);
            rows[ctr].setLayoutParams(new LayoutParams (LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT));
            FieldsLayout.addView(rows[ctr]);

            labels[ctr] = new TextView(Compute.this);
            labels[ctr].setText(items[ctr]);
            labels[ctr].setMinimumWidth(textViewSizeDp);
            rows[ctr].addView(labels[ctr]);

            fields[ctr] = new EditText(Compute.this);
            fields[ctr].setMinimumWidth(textFieldSizeDp);
            rows[ctr].addView(fields[ctr]);

        }
    }
    else{
        finish();
    }



    aButton.setOnClickListener(new OnClickListener() {  


        public void onClick(View v) {   

              Intent i = new Intent(Compute.this, Total.class);
              //I believe this causes the error
                for(int ctr=0;ctr<fields.length;ctr++){
                    itemName[ctr] = labels[ctr].getText().toString();
                    }

                for(int ctr=0;ctr<fields.length;ctr++){
                    itemHour[ctr] = Integer.parseInt(fields[ctr].getText().toString());
                    }
                //until here
              i.putExtra("hours",itemHour);
              i.putExtra("items",itemName);
              startActivity(i);
              }});     

}

here’s the error log: (or is this it?)

01-14 09:37:16.047: W/Trace(768): Unexpected value from nativeGetEnabledTags: 0
01-14 09:37:16.187: E/AndroidRuntime(768): FATAL EXCEPTION: main
01-14 09:37:16.187: E/AndroidRuntime(768): java.lang.NullPointerException
01-14 09:37:16.187: E/AndroidRuntime(768):  at com.example.mpc.Compute$1.onClick(Compute.java:82)
01-14 09:37:16.187: E/AndroidRuntime(768):  at android.view.View.performClick(View.java:4202)
01-14 09:37:16.187: E/AndroidRuntime(768):  at android.view.View$PerformClick.run(View.java:17340)
01-14 09:37:16.187: E/AndroidRuntime(768):  at android.os.Handler.handleCallback(Handler.java:725)
01-14 09:37:16.187: E/AndroidRuntime(768):  at android.os.Handler.dispatchMessage(Handler.java:92)
01-14 09:37:16.187: E/AndroidRuntime(768):  at android.os.Looper.loop(Looper.java:137)
01-14 09:37:16.187: E/AndroidRuntime(768):  at android.app.ActivityThread.main(ActivityThread.java:5039)
01-14 09:37:16.187: E/AndroidRuntime(768):  at java.lang.reflect.Method.invokeNative(Native Method)
01-14 09:37:16.187: E/AndroidRuntime(768):  at java.lang.reflect.Method.invoke(Method.java:511)
01-14 09:37:16.187: E/AndroidRuntime(768):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
01-14 09:37:16.187: E/AndroidRuntime(768):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
01-14 09:37:16.187: E/AndroidRuntime(768):  at dalvik.system.NativeStart.main(Native Method)

Answer 1

Check out following things:

1. Make sure your field array is initialized properly.
2. Make sure that the length of itemName is same as that of fields.length and it should be properly initialized.
3. Make sure that the length of labels is same as that of fields.length and it should be properly initialized.
4. Make sure that the length of itemHour is same as that of fields.length and it should be properly initialized.