Question

我再次陷入使用复选框实现列表视图。我必须在列表视图中显示带有复选框的黑莓联系人。当我运行代码运行时，它消耗额外的内存。我发布的代码中没有显示任何内容。请告诉我我在哪里做错了以及该怎么做才能纠正它。

更新：代码现在正在运行，但它在滚动时抛出数组超出绑定的异常。你能告诉我问题在哪里吗？

 public class CheckboxListField extends MainScreen implements ListFieldCallback {
        private Vector _listData = new Vector();
        private ListField listField;
        private ContactList blackBerryContactList;
        private BlackBerryContact blackBerryContact;
        private Vector blackBerryContacts;

        private class ChecklistData
        {
            private String _stringVal;
            private boolean _checked;

            ChecklistData(String stringVal, boolean checked)
            {
                _stringVal = stringVal;
                _checked = checked;
            }

            //Get/set methods.
            private String getStringVal()
            {
                return _stringVal;
            }

            private boolean isChecked()
            {
                return _checked;
            }
        }

        CheckboxListField() 
        {    
            listField = new ListField();
            listField.setCallback(this);
            reloadContactList();

            for(int count = 0; count < blackBerryContacts.size(); ++count)
            {
                BlackBerryContact item =
                    (BlackBerryContact)blackBerryContacts.elementAt(count);
                    String displayName = getDisplayName(item);
                    add(new RichTextField("Check1"));
                    _listData.addElement(new ChecklistData(displayName, false));
                    add(new RichTextField("Check2"));
                    listField.insert(count);
                    add(new RichTextField("Check3"));
                    add(new RichTextField(blackBerryContacts.size()));
                    add(new RichTextField(displayName));
                }
            add(listField);
        }

        private boolean reloadContactList()
        {
            try {
                blackBerryContactList =
                    (ContactList)PIM.getInstance().openPIMList
                    (PIM.CONTACT_LIST, PIM.READ_ONLY);

                Enumeration allContacts = blackBerryContactList.items();
                blackBerryContacts = enumToVector(allContacts);
                listField.setSize(blackBerryContacts.size());
                return true;
            }   catch (PIMException e)
            {
              return false;
            }
        } 

        //Convert the list of contacts from an Enumeration to a Vector
        private Vector enumToVector(Enumeration contactEnum) {
            Vector v = new Vector();

            if (contactEnum == null)
              return v;

            while (contactEnum.hasMoreElements()) {
              v.addElement(contactEnum.nextElement());
            }

            return v;
          }

        public void drawListRow(ListField list, Graphics graphics, int index, int y, int w) 
        {
            ChecklistData currentRow = (ChecklistData)this.get(list, index); 
            StringBuffer rowString = new StringBuffer();

            if (currentRow.isChecked())
            {
                rowString.append(Characters.BALLOT_BOX_WITH_CHECK);
            }
            else
            {
                rowString.append(Characters.BALLOT_BOX);
            }

            //Append a couple spaces and the row's text.
            rowString.append(Characters.SPACE);
            rowString.append(Characters.SPACE);
            rowString.append(currentRow.getStringVal());

            //Draw the text.
            graphics.drawText(rowString.toString(), 0, y, 0, w);
        }

        public static String getDisplayName(Contact contact) 
          {
              if (contact == null)
              {
                  return null;    
              }

              String displayName = null;

              // First, see if there is a meaningful name set for the contact.
              if (contact.countValues(Contact.NAME) > 0) {
                  final String[] name = contact.getStringArray(Contact.NAME, 0);
                  final String firstName = name[Contact.NAME_GIVEN];
                  final String lastName = name[Contact.NAME_FAMILY];
                  if (firstName != null && lastName != null) {
                      displayName = firstName + " " + lastName;
                  } else if (firstName != null) {
                      displayName = firstName;
                  } else if (lastName != null) {
                      displayName = lastName;
                  }

                  if (displayName != null) {
                      final String namePrefix = name[Contact.NAME_PREFIX];
                      if (namePrefix != null) {
                          displayName = namePrefix + " " + displayName;
                      }
                      return displayName;
                  }
              }
              return displayName;
          }

        //Returns the object at the specified index.
        public Object get(ListField list, int index) 
        { 
            return _listData.elementAt(index);
        }

        //Returns the first occurence of the given String, bbeginning the search at index, 
        //and testing for equality using the equals method.
        public int indexOfList(ListField list, String p, int s) 
        {
           return -1;
        }

        //Returns the screen width so the list uses the entire screen width.
        public int getPreferredWidth(ListField list) 
        {
            return Display.getWidth();
        }
    }

Answer 1

创建自定义列表后。将其添加到VerticalFieldManager中。然后将此垂直FieldManager添加到屏幕。在这里z一些代码...在你添加列表

的屏幕上写下这段代码

   int DISPLAY_WIDTH = Display.getWidth();
   int DISPLAY_HEIGHT = Display.getHeight();
   VerticalFieldManager VFM mListManager = new SizedVFM(DISPLAY_WIDTH, DISPLAY_HEIGHT - 40);
   mListManager.add(mListField);
   add(mListManager);

黑莓：复选框和列表视图

1 个答案: