如何从AlertDialog获取setMultiChoiceItems项？

AlertDialog.Builder builder = new AlertDialog.Builder(context);
builder.setTitle("选择项")
       .setMultiChoiceItems(items, checkedItems, new DialogInterface.OnMultiChoiceClickListener() {
           @Override
           public void onClick(DialogInterface dialog, int which, boolean isChecked) {
               ListView listView = ((AlertDialog) dialog).getListView();
               SparseBooleanArray checkedItemPositions = listView.getCheckedItemPositions();
               for (int i = 0; i < checkedItemPositions.size(); i++) {
                   int position = checkedItemPositions.keyAt(i);
                   boolean isChecked = checkedItemPositions.valueAt(i);
                   // 处理选中项的索引和状态
               }
           }
       })
       .setPositiveButton("确定", new DialogInterface.OnClickListener() {
           @Override
           public void onClick(DialogInterface dialog, int which) {
               // 确定按钮的点击事件处理
           }
       })
       .setNegativeButton("取消", new DialogInterface.OnClickListener() {
           @Override
           public void onClick(DialogInterface dialog, int which) {
               // 取消按钮的点击事件处理
           }
       });

AlertDialog dialog = builder.create();
dialog.show();