Question

我正在传递一个整数数组列表，该列表保存选择并根据选择检索它，但是当我从检查选择中删除该项目时，它并不是从以文本显示的数组列表中删除。这是我处理多重检查的逻辑。

    public class MainFragment extends Fragment {

    private Button buttonUser;
    String[] listItems;
    boolean[] checkedItems;
    ArrayList<Integer> mUserItems = new ArrayList<>();
    private Context context;
    private AppCompatTextView compatTextView;

    public static MainFragment newInstance() {
        return new MainFragment();
    }

    @Override
    public void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        listItems = getResources().getStringArray(R.array.person_array);
        checkedItems = new boolean[listItems.length];
        context = getActivity();
    }

    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_main, container, false);
        buttonUser = (Button) view.findViewById(R.id.buttonUser);
        compatTextView = (AppCompatTextView) view.findViewById(R.id.text_view_selection);

        buttonUser.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                AlertDialog.Builder alert = new AlertDialog.Builder(context);
                alert.setTitle("Select Person");
                alert.setMultiChoiceItems(listItems, checkedItems, new DialogInterface.OnMultiChoiceClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which, boolean isChecked) {
                        if (isChecked) {
                            if (!mUserItems.contains(which)) {
                                mUserItems.add(which);
                            }
                        } else if (!mUserItems.contains(which)){
                            mUserItems.remove(which);
                        }
                    }
                });

                alert.setCancelable(false);
                alert.setPositiveButton(android.R.string.ok, new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        String items = "";
                        for (int i = 0; i < mUserItems.size(); i++) {
                            items = items.concat(listItems[mUserItems.get(i)]);
                            if (i != mUserItems.size() - 1) {
                                items = items + ", ";
                            }
                            compatTextView.setText(items);
                        }
                    }
                });
                alert.setNegativeButton(android.R.string.cancel, new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        dialog.dismiss();
                    }
                });
                AlertDialog dialog = alert.create();
                dialog.show();
            }
        });
        return view;
    }
}

而且我没有掌握逻辑的这一部分如何处理

@Override
public void onClick(DialogInterface dialog, int which, boolean isChecked) {
                    if (isChecked) {
                        if (!mUserItems.contains(which)) {
                            mUserItems.add(which);
                        }
                    } else if (!mUserItems.contains(which)){
                        mUserItems.remove(which);
                    }
                }

这是正确的，但是当我从警报对话框中取消选择时，列表不会更新并显示以前的检查数据。

Answer 1

我认为，如果isChecked为false，则else if部分将产生false。可能是这样吗：： else if (mUserItems.contains(which))

如何在“多个复选框选择”中从ArrayList中删除未选择的元素？

1 个答案: