Show list selected item on positive button pressed when AlertDialog re opens

Question

I have an alert dialog in which contains multiple list selection listener. Problem is that when i open first dialog after selection of multiple items i press positive button then on re open alert dialog it show nothing selected what i selected items when last opened.

   final CharSequence[] dialogList=  list.toArray(new CharSequence[list.size()]);
    final AlertDialog.Builder builderDialog = new AlertDialog.Builder(SchoolFieldsData.this);
    builderDialog.setTitle("Enter Average Fee");
    int count = dialogList.length;
    boolean[] is_checked = new boolean[count]; // set is_checked boolean false;

    // Creating multiple selection by using setMutliChoiceItem method
    builderDialog.setMultiChoiceItems(dialogList, is_checked,
            new DialogInterface.OnMultiChoiceClickListener() {
                public void onClick(DialogInterface dialog,
                                    int whichButton, boolean isChecked) {
                }
            });

    builderDialog.setPositiveButton("OK",
            new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {

                    ListView list = ((AlertDialog) dialog).getListView();
                    // make selected item in the comma seprated string
                    StringBuilder stringBuilder = new StringBuilder();
                    for (int i = 0; i < list.getCount(); i++) {
                        boolean checked = list.isItemChecked(i);

                        if (checked) {
                            if (stringBuilder.length() > 0) stringBuilder.append(",");
                            stringBuilder.append(list.getItemAtPosition(i));

                        }
                    }

                    /*Check string builder is empty or not. If string builder is not empty.
                      It will display on the screen.
                     */
                    if (stringBuilder.toString().trim().equals("")) {

                   //     ((TextView) findViewById(R.id.text)).setText("Click here to open Dialog");
                        stringBuilder.setLength(0);

                    } else {

                   //     ((TextView) findViewById(R.id.text)).setText(stringBuilder);
                    }
                }
            });

    builderDialog.setNegativeButton("Cancel",
            new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                 //   ((TextView) findViewById(R.id.text)).setText("Click here to open Dialog");
                }
            });
    AlertDialog alert = builderDialog.create();
    alert.show();

Answer 1

This is because every time this code ins invoked a new AlertDialog is built (line 2) and new array of is_checked is provided to it.

Try to restore the state, for example keep is_checked array in different place and inside the positive button handler save the state to this array (instead of the line boolean checked = list.isItemChecked(i);).