根目录下带有子项的可扩展列表视图

Question

我正在尝试制作具有以下结构的列表视图：

Listview
    -> child
    -> child
    -> group
           -> child
           -> child
    -> child

我将如何去完成这个？

我是否必须让一个小组像孩子一样行事，或者是否可以像这样正确地做到这一点：

我有一个对象 MenuRow

public class MenuRow {
public String title;

public MenuRow(String title) {
    this.title = title;
}

}

然后我有扩展 MenuRow 的 MenuGroup 和 MenuChild，这允许我执行以下操作：

    ArrayList<MenuRow> menu = new ArrayList<MenuRow>();
    menu.add(new MenuChild("row 1"));
    menu.add(new MenuChild("row 2"));
    MenuGroup group = new MenuGroup("group");
    MenuChild groupChild = new MenuChild("group child");
    group.items.add(groupChild);
    menu.add(group);

我似乎不知道应该如何处理适配器中的业务。

@Override
    public Object getChild(int groupPosition, int childPosition) {
        MenuRow row = menu.get(groupPosition);
        if (row instanceof MenuGroup) {
            ArrayList<MenuChild> chList = ((MenuGroup) row).getItems();
        }
        else{
                return null;
        }

        return chList;
    }

例如，这种方法并不真正适合我的解决方案。我应该如何努力实现我的目标？我需要使用不同的适配器吗？ （我目前的一个扩展 BaseExpandableListAdapter）

Answer 1

我已经处理过这样的问题，这是我使用的方法：

并创建了一个类对象，用作子视图和父视图的左侧菜单项

public class LeftMenuItem {

    int mTextId;
    int mImageId;
    //Action to be taken after clicking on the item
    String mAction;

    public LeftMenuItem(int textId, int imageId,String action) {
        this.mTextId = textId;
        this.mImageId = imageId;
        this.mAction = action;
    }

    public int getTextId() {
        return mTextId;
    }

    public void setTextId(int textId) {
        this.mTextId = textId;
    }

    public int getImageId() {
        return mImageId;
    }

    public void setImageId(int imageId) {
        this.mImageId = imageId;
    }

    public String getAction() {
        return mAction;
    }

    public void setAction(String action) {
        this.mAction = action;
    }

}

并创建了我的可扩展列表项，如果找到，它将包含一个 leftmenuitem 父项和子项数组列表

public class ExpandableLeftMenuItem {

    LeftMenuItem mParentItem;
    ArrayList<LeftMenuItem> mChildItems;

    public ExpandableLeftMenuItem(LeftMenuItem parentItem,
            ArrayList<LeftMenuItem> childItems) {
        this.mParentItem = parentItem;
        this.mChildItems = childItems;
    }

    public LeftMenuItem getParentItem() {
        return mParentItem;
    }

    public void setParentItem(LeftMenuItem parentItem) {
        this.mParentItem = parentItem;
    }

    public ArrayList<LeftMenuItem> getChildItems() {
        return mChildItems;
    }

    public void setChildItems(ArrayList<LeftMenuItem> childItems) {
        this.mChildItems = childItems;
    }   

}

然后我处理ExpandableListView onChildClickListener 和 onGroupClickListener 如下

// In Case of clicking on an item that has children, then get the action
        // of this child item and show the screen with this action
        mLeftMenu.setOnChildClickListener(new OnChildClickListener() {
            @Override
            public boolean onChildClick(ExpandableListView parent, View view, int groupPosition, int childPosition, long id) {
                if (!mLeftMenuItems.get(groupPosition).getChildItems().isEmpty()) {

                    String action = ((LeftMenuItem) mLeftMenuItems.get(groupPosition).getChildItems().get(childPosition)).getAction();
                    setSelectedSection(action);
                    handleLeftMenuClick(action);

                    return true;
                }
                return false;
            }
        });
        // In Case of clicking on an item that has no children, then get the
        // action of this item and show the screen with this action
        mLeftMenu.setOnGroupClickListener(new OnGroupClickListener() {

            @Override
            public boolean onGroupClick(ExpandableListView parent, View view, int groupPosition, long id) {
                if (mLeftMenuItems.get(groupPosition).getChildItems().isEmpty()) {
                    String action = ((LeftMenuItem) mLeftMenuItems.get(groupPosition).getParentItem()).getAction();
                    setSelectedSection(action);
                    handleLeftMenuClick(action);
// Return true to stop parent from expanding or collapsing group
                    return true;
                }
// Return true to handle click as parent by expanding or collapsing group
                    return false;
            }
        });

那么对于下面的

ExpandableListView:
     group
     group
     group
          child
          child
     group
          child
          child

您将创建以下菜单项：

ArrayList<ExpandableLeftMenuItem> mMenuItems = new ArrayList<ExpandableLeftMenuItem>();
mMenuItems.add(new ExpandableLeftMenuItem(new LeftMenuItem(parent1Text,parent1Image,action1),new ArrayList<LeftMenuItem>()));

mMenuItems.add(new ExpandableLeftMenuItem(new LeftMenuItem(parent2Text,parent2Image,action2),new ArrayList<LeftMenuItem>()));

ArrayList<LeftMenuItem> parent3Children = new ArrayList<LeftMenuItem>();
parent3Children.add(new LeftMenuItem(parent3Child1TextId,parent3Child1ImageId,parent3Child1action));
parent3Children.add(new LeftMenuItem(parent3Child2TextId,parent3Child2ImageId,parent3Child2action));

mMenuItems.add(new ExpandableLeftMenuItem(new LeftMenuItem(parent1Text,parent1Image,action1),parent3Children ));

这样，您处理了子位置和组位置以采取不同的操作。

我希望这会有所帮助。