由于复选框onclick上的“多项选择”对话框，导致活动崩溃

Question

当我单击复选框时，该对话框可以正常工作，但是当我再次单击并取消选中当前选中的项目时，活动崩溃。如何正确编码呢？我仍然对Android还是陌生的，因为我只在空闲时间这样做。

代码：

mAllergies.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            final AlertDialog.Builder mBuilder = new AlertDialog.Builder(DietGeneration.this);
            mBuilder.setTitle("Please select from the list of allergies below.");
            mBuilder.setMultiChoiceItems(listItems, checkedItems, new DialogInterface.OnMultiChoiceClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int position, boolean isChecked) {
                    if (isChecked) {
                        if(!mUserItems.contains(position)) {
                            mUserItems.add(position);
                        }else{
                            mUserItems.remove(position);
                        }
                    } else{
                        if(mUserItems.contains(position)) {
                            mUserItems.remove(position);
                        }
                    }
                }
            });

            mBuilder.setCancelable(false);
            mBuilder.setPositiveButton("OK", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {

                    for (int i = 0; i < mUserItems.size(); i++) {
                        item = item + listItems[mUserItems.get(i)];
                        if (i != mUserItems.size() - 1) {
                            item = item + ", ";
                        }
                    }
                    mItemSelected.setText(item);
                    if (mUserItems.isEmpty()) {
                        mUserItems.clear();
                        mAllergies.setChecked(false);
                    } else {
                        mAllergies.setChecked(true);
                    }
                }
            });

            mBuilder.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int i) {
                    if (mUserItems.isEmpty()) {
                        mUserItems.clear();
                        mAllergies.setChecked(false);
                    } else {
                        mAllergies.setChecked(false);
                    }
                    dialog.dismiss();
                }
            });

            mBuilder.setNeutralButton("Clear All", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {

                    for (int i = 0; i < checkedItems.length; i++) {
                        checkedItems[i] = false;
                        mUserItems.clear();
                        mItemSelected.setText("");
                        if (mItemSelected.getText() == "") {
                            mAllergies.setChecked(false);
                        } else {
                            mAllergies.setChecked(false);
                        }
                    }
                }
            });

            AlertDialog mDialog = mBuilder.create();
            mDialog.show();

        }
    });

LOGCAT：

java.lang.IndexOutOfBoundsException: Invalid index 1, size is 1
    at java.util.ArrayList.throwIndexOutOfBoundsException(ArrayList.java:260)
    at java.util.ArrayList.remove(ArrayList.java:408)
    at com.example.mgimoro.dietgo.DietGeneration$3$1.onClick(DietGeneration.java:93)
    at android.support.v7.app.AlertController$AlertParams$4.onItemClick(AlertController.java:1080)
    at android.widget.AdapterView.performItemClick(AdapterView.java:319)
    at android.widget.AbsListView.performItemClick(AbsListView.java:1209)
    at android.widget.AbsListView$PerformClick.run(AbsListView.java:3290)
    at android.widget.AbsListView.onTouchUp(AbsListView.java:4299)
    at android.widget.HwAbsListView.onTouchUp(HwAbsListView.java:465)
    at android.widget.AbsListView.onTouchEvent(AbsListView.java:3998)
    at android.view.View.dispatchTouchEvent(View.java:9480)
    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2662)
    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2304)
    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2668)
    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2318)
    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2668)
    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2318)
    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2668)
    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2318)
    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2668)
    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2318)
    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2668)
    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2318)
    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2668)
    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2318)
    at android.view.ViewGroup.dispatchTransformedTouchEvent(ViewGroup.java:2668)
    at android.view.ViewGroup.dispatchTouchEvent(ViewGroup.java:2318)
    at com.android.internal.policy.PhoneWindow$DecorView.superDispatchTouchEvent(PhoneWindow.java:2512)
    at com.android.internal.policy.PhoneWindow.superDispatchTouchEvent(PhoneWindow.java:1813)
    at android.app.Dialog.dispatchTouchEvent(Dialog.java:843)
    at android.support.v7.view.WindowCallbackWrapper.dispatchTouchEvent(WindowCallbackWrapper.java:68)
    at com.android.internal.policy.PhoneWindow$DecorView.dispatchTouchEvent(PhoneWindow.java:2473)
    at android.view.View.dispatchPointerEvent(View.java:9704)