如何在android中创建可扩展布局？

Question

谁能帮我在 android 市场上创建一个可扩展的视图，比如更多按钮？ 当我们点击更多按钮时，它将展开视图，其中包含有关 android 市场中应用程序的更多详细信息..

任何帮助将不胜感激..

谢谢

sathish

Answer 1

我一直在做类似的事情。

目前在more/less栏模式下看起来像这样：

它仍在进行中，但可以查看项目和源代码here

Answer 2

也许实现这一点的最佳方法是使用ArrayAdapter。当您单击更多按钮获取更多数据并使用addAll() 方法将所有新获取的数据添加到适配器。 addAll() 会自动将更改传播到 ListView，因此不必费心显式通知它。

Answer 3

public class ModifiedExpandableList extends Activity {

    ExpandableListAdapter mAdapter;
    private ExpandableListView mExpandableListView;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main_copy);
        // set our list
        mExpandableListView = (ExpandableListView)findViewById(R.id.list);
        // Set up our adapter
        mAdapter = new MyExpandableListAdapter(this);
        mExpandableListView.setAdapter(mAdapter);
        // Need no icon as of now
        mExpandableListView.setGroupIndicator(null);
        registerForContextMenu(mExpandableListView);
    }

    @Override
    public void onCreateContextMenu(ContextMenu menu, View v, ContextMenuInfo menuInfo) {
        menu.setHeaderTitle("Sample menu");
        menu.add(0, 0, 0,"dd");
    }

    @Override
    public boolean onContextItemSelected(MenuItem item) {
        ExpandableListContextMenuInfo info = (ExpandableListContextMenuInfo) item.getMenuInfo();

        String title = ((TextView) info.targetView).getText().toString();

        int type = ExpandableListView.getPackedPositionType(info.packedPosition);
        if (type == ExpandableListView.PACKED_POSITION_TYPE_CHILD) {
            int groupPos = ExpandableListView.getPackedPositionGroup(info.packedPosition); 
            int childPos = ExpandableListView.getPackedPositionChild(info.packedPosition); 
            Toast.makeText(this, title + ": Child " + childPos + " clicked in group " + groupPos,
                    Toast.LENGTH_SHORT).show();
            return true;
        } else if (type == ExpandableListView.PACKED_POSITION_TYPE_GROUP) {
            int groupPos = ExpandableListView.getPackedPositionGroup(info.packedPosition); 
            Toast.makeText(this, title + ": Group " + groupPos + " clicked", Toast.LENGTH_SHORT).show();
            return true;
        }

        return false;
    }

    /**
     * A simple adapter which maintains an ArrayList of photo resource Ids. 
     * Each photo is displayed as an image. This adapter supports clearing the
     * list of photos and adding a new photo.
     *
     */
    public class MyExpandableListAdapter extends BaseExpandableListAdapter {

        Context mContext;
        public MyExpandableListAdapter(Context context){
            this.mContext = context;
        }

        // Sample data set.  children[i] contains the children (String[]) for groups[i].
        private String[] groups = { "People Names", "Dog Names", "Cat Names", "Fish Names" };
        private String[][] children = {
                { "Arnold", "Barry", "Chuck", "David" },
                { "Ace", "Bandit", "Cha-Cha", "Deuce" },
                { "Fluffy", "Snuggles","ddef","afadsfasf" },
                { "Goldy", "Bubbles","sfef","dafs" }
        };

        public Object getChild(int groupPosition, int childPosition) {
            return children[groupPosition][childPosition];
        }

        public long getChildId(int groupPosition, int childPosition) {
            return childPosition;
        }

        public int getChildrenCount(int groupPosition) {
            int result=4;

            return result;
       }

        public View getChildView(int groupPosition, int childPosition, boolean isLastChild,
                View convertView, ViewGroup parent) {
            View v = null;
            // changed here
                LayoutInflater li = ModifiedExpandableList.this.getLayoutInflater();
                v = li.inflate(R.layout.child_view,null);
                TextView tv = (TextView)v.findViewById(R.id.TextView01);
                tv.setText(getChild(groupPosition, childPosition).toString());
                ImageView im = (ImageView)v.findViewById(R.id.ImageView01);
                im.setBackgroundDrawable(ModifiedExpandableList.this.getResources().getDrawable(R.drawable.closearrow));
            return v;
        }

        public Object getGroup(int groupPosition) {
            return groups[groupPosition];
        }

        public int getGroupCount() {
            return groups.length;
        }

        public long getGroupId(int groupPosition) {
            return groupPosition;
        }

        public View getGroupView(int groupPosition, boolean isExpanded, View convertView,
                ViewGroup parent) {
            // change here to modify parent group layout
            View v = null;
            LayoutInflater li = ModifiedExpandableList.this.getLayoutInflater();
            v = li.inflate(R.layout.parent_view,null);
            TextView tv = (TextView)v.findViewById(R.id.TextView01);
            tv.setText(getGroup(groupPosition).toString());
            ImageView im = (ImageView)v.findViewById(R.id.ImageView01);
            im.setBackgroundDrawable(ModifiedExpandableList.this.getResources().getDrawable(R.drawable.closearrow));
            if(isExpanded){
                im.setBackgroundDrawable(ModifiedExpandableList.this.getResources().getDrawable(R.drawable.closearrow_b));
            }
            return v;
        }

        public boolean isChildSelectable(int groupPosition, int childPosition) {
            return true;
        }

        public boolean hasStableIds() {
            return true;
        }

    }
}