"Specified child already has a parent.You must call removeView() on child's parent first." Exception in android

Question

I am retrieving information from server and trying to display it in a tabular format,hence using json object.

Code :

  JSONArray jsonArray = new JSONArray(jsonResult);
                TableLayout tv=(TableLayout) findViewById(R.id.table);
                tv.removeAllViewsInLayout();

                int flag=1;
                for (int i = 0; i < jsonArray.length() ; i++) {
                    //JSONObject object1 = jsonArray.getJSONObject(i);

                        TableRow tr=new TableRow(viewtimetable.this);

                        tr.setLayoutParams(new LayoutParams(
                                   LayoutParams.FILL_PARENT,
                                   LayoutParams.WRAP_CONTENT));

                        if(flag==1)
                        {

                            TextView col1=new TextView(viewtimetable.this);
                             col1.setText("Day");
                             col1.setTextColor(Color.BLUE);
                             col1.setTextSize(15);
                             tr.addView(col1);


                            TextView col2=new TextView(viewtimetable.this);
                             col2.setPadding(10, 0, 0, 0);
                             col2.setTextSize(15);
                             col2.setText("7:30-9:10AM");
                             col2.setTextColor(Color.BLUE);
                             tr.addView(col2);

                            TextView col3=new TextView(viewtimetable.this);
                             col3.setPadding(10, 0, 0, 0);
                             col3.setText("9:20-11:00AM");
                             col3.setTextColor(Color.BLUE);
                             col3.setTextSize(15);
                             tr.addView(col3);

                            TextView col4=new TextView(viewtimetable.this);
                             col4.setPadding(10, 0, 0, 0);
                             col4.setText("11:10-12:50PM");
                             col4.setTextColor(Color.BLUE);
                             col4.setTextSize(15);
                             tr.addView(col4);

                            TextView col5=new TextView(viewtimetable.this);
                             col5.setPadding(10, 0, 0, 0);
                             col5.setText("1:40-3:20PM");
                             col5.setTextColor(Color.BLUE);
                             col5.setTextSize(15);
                             tr.addView(col5);

                            TextView col6=new TextView(viewtimetable.this);
                             col6.setPadding(10, 0, 0, 0);
                             col6.setText("3:30-5:00PM");
                             col6.setTextColor(Color.BLUE);
                             col6.setTextSize(15);
                             tr.addView(col6);

                             tv.addView(tr);

                             final View vline = new View(viewtimetable.this);

                             vline.setLayoutParams(new TableRow.LayoutParams(TableRow.LayoutParams.FILL_PARENT, 2));
                             vline.setBackgroundColor(Color.BLUE);



                        tv.addView(vline);
                        flag=0;


                        }

                        else
                        {

                       try{

                            JSONObject json_data = jsonArray.getJSONObject(i);

                            //Log.i("log_tag","id: "+json_data.getInt("f1")+
                             //         ", Username: "+json_data.getString("f2")+
                               //       ", No: "+json_data.getInt("f3"));


                            //((ViewGroup)tr.getParent()).removeView(tr);

                    TextView b=new TextView(viewtimetable.this);
                        String stime=json_data.getString("day");
                        b.setText(stime);
                        b.setTextColor(Color.RED);
                        b.setTextSize(15);
                        tr.addView(b);


                       TextView b1=new TextView(viewtimetable.this);
                        b1.setPadding(10, 0, 0, 0);
                        b1.setTextSize(15);
                        if(json_data.getString("slot").equals("7:30-9:10AM")){
                        String stime1=json_data.getString("subject");
                         b1.setText(stime1);
                        }
                        b1.setTextColor(Color.WHITE);
                        tr.addView(b1);

                      TextView b2=new TextView(viewtimetable.this);
                     b2.setPadding(10, 0, 0, 0);

                        if(json_data.getString("slot").equals("9:20-11:00AM")){
                            String stime2=json_data.getString("subject");
                             b2.setText(stime2);
                            }
                        b2.setTextColor(Color.RED);
                        b2.setTextSize(15);
                        tr.addView(b2);

                        TextView b3=new TextView(viewtimetable.this);
                        b3.setPadding(10, 0, 0, 0);

                           if(json_data.getString("slot").equals("11:10-12:50PM")){
                               String stime3=json_data.getString("subject");
                                b3.setText(stime3);
                               }
                           b3.setTextColor(Color.RED);
                           b3.setTextSize(15);
                           tr.addView(b2);  

                           TextView b4=new TextView(viewtimetable.this);
                           b4.setPadding(10, 0, 0, 0);

                              if(json_data.getString("slot").equals("1:40-3:20PM")){
                                  String stime4=json_data.getString("subject");
                                   b4.setText(stime4);
                                  }
                              b4.setTextColor(Color.RED);
                              b4.setTextSize(15);
                              tr.addView(b2);     

                              TextView b5=new TextView(viewtimetable.this);
                              b5.setPadding(10, 0, 0, 0);

                                 if(json_data.getString("slot").equals("3:30-5:00PM")){
                                     String stime5=json_data.getString("subject");
                                      b5.setText(stime5);
                                     }
                                 b5.setTextColor(Color.RED);
                                 b5.setTextSize(15);
                                 tr.addView(b2);        

                          tv.addView(tr);


                       }catch(JSONException e){
                           content.setText("jsonexception");
                       }
                final View vline1 = new View(viewtimetable.this);
              vline1.setLayoutParams(new TableRow.LayoutParams(TableRow.LayoutParams.FILL_PARENT, 1));
              vline1.setBackgroundColor(Color.WHITE);
              tv.addView(vline1);       


                        }

After searching for a solution i found here but i don't know where to use this line.I am not getting about which child the exception is!It would be a great help if you can explain this.

Question: I know from the above link that the following line is the solution for my problem.

((ViewGroup)scrollChildLayout.getParent()).removeView(scrollChildLayout);

But in my case where,how and why to use this?

Answer 1

In the code of TextViews b3, b4 and b5 you are trying to do tr.addView(b2); so b2 is added 4 times in total. this should be b3, b4 and b5

On a sidenote, try to learn how to read crash logs. The Exception should state exactly on what line of code the error is on, so probably on the second occurence of tr.addView(b2);