Android: Select items in a multi-select ListView inside AlertDialog

Question

I am new to android development and struggling with how to select certain items in a listview hosted by an alertdialog. In the below code, lv.setItemChecked doesn\'t work as

Answer 1

I found the correct Solutions:

    public void alertMultipleChoiceItems(){
    final CharSequence[] dialogList = Symbollist.toArray(new CharSequence[Symbollist.size()]);
    HashSet uniqueValues = new HashSet<>(Symbollist);
    Symbollist.clear();
    for (String value : uniqueValues) {
        //... //Do something
        Symbollist.add(value);
    }
    AlertDialog.Builder builder = new AlertDialog.Builder(AddPackageStep3.this);
    selectedItems = new ArrayList();
    // set the dialog title
    boolean[] itemChecked = new boolean[selectedItems.size()];

    builder.setMultiChoiceItems(dialogList,null, new DialogInterface.OnMultiChoiceClickListener() {

                @Override
                public void onClick(DialogInterface dialog, int which, boolean isChecked) {

                    if (isChecked) {
                        // if the user checked the item, add it to the selected items
                        selectedItems.add(which);
                    }

                    else if (selectedItems.contains(which)) {
                        // else if the item is already in the array, remove it
                        selectedItems.remove(Integer.valueOf(which));
                    }

                    // you can also add other codes here,
                    // for example a tool tip that gives user an idea of what he is selecting
                    // showToast("Just an example description.");
                }

            })
            // Set the action buttons
            .setPositiveButton("OK", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int id) {

                    // user clicked OK, so save the mSelectedItems results somewhere
                    // here we are trying to retrieve the selected items indices
                    String selectedIndex = "";
                    for(Integer i : selectedItems){
                        selectedIndex += i + ", ";
                    }

                    //showToast("Selected index: " + selectedIndex);

                }
            })

            .setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int id) {
                    // removes the AlertDialog in the screen
                }
            })
            .show();

}