Android支持铺展/收缩功能的列表控件

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最近在做一个Rss阅读器，看了下别人做的阅读器中的列表控件可以展开、收缩，我就在网上搜索了一下。下面就我找到的一个小例子，给大家分享一下。

ActivityMain .java

package study.com.android;

import android.app.ExpandableListActivity;
import android.os.Bundle;
import android.view.ContextMenu;
import android.view.MenuItem;
import android.view.View;
import android.view.ContextMenu.ContextMenuInfo;
import android.widget.ExpandableListAdapter;
import android.widget.ExpandableListView;
import android.widget.TextView;
import android.widget.Toast;
import android.widget.ExpandableListView.ExpandableListContextMenuInfo;

public class ActivityMain extends ExpandableListActivity {

	private ExpandableListAdapter mAdapter;

	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		this.setTitle("ExpandableList");
		mAdapter = new MyExpandableListAdapter(this);
		setListAdapter(mAdapter);
		registerForContextMenu(this.getExpandableListView());
	}

	// 为列表的每一项创建上下文菜单（即长按后 呼出的菜单）
	@Override
	public void onCreateContextMenu(ContextMenu menu, View v,
			ContextMenuInfo menuInfo) {
		menu.setHeaderTitle("ContexMenu");
		menu.add(0, 0, 0, "ContextMenu");
	}

	// 单击上下文菜单后的逻辑
	@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 + "-Group Index" + groupPos + "Child Index:"
							+ childPos, Toast.LENGTH_SHORT).show();
			return true;
		}
		return false;
	}
}

MyExpandableListAdapter.java

package study.com.android;

import android.content.Context;
import android.view.Gravity;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AbsListView;
import android.widget.BaseExpandableListAdapter;
import android.widget.TextView;

public class MyExpandableListAdapter extends BaseExpandableListAdapter {

	private Context mContext;

	// 父列表数据
	private String[] groups = { "group1", "group2", "group3", "group4", "" };

	// 子列表数据
	private String[][] children = { { "child1" }, { "child1", "child2" },
			{ "child1", "child2", "child3" },
			{ "child1", "child2", "child3", "child4" }, };

	MyExpandableListAdapter(Context context) {
		mContext = context;
	}

	@Override
	public Object getChild(int groupPosition, int childPosition) {
		// TODO Auto-generated method stub
		return children[groupPosition][childPosition];
	}

	@Override
	public long getChildId(int groupPosition, int childPosition) {
		// TODO Auto-generated method stub
		return childPosition;
	}

	// 取子列表中的某一项的view
	@Override
	public View getChildView(int groupPosition, int childPosition,
			boolean isLastChild, View convertView, ViewGroup parent) {
		TextView textView = getGenericView();
		;
		textView.setText(getChild(groupPosition, childPosition).toString());
		return textView;
	}

	@Override
	public int getChildrenCount(int groupPosition) {
		// TODO Auto-generated method stub
		return children[groupPosition].length;
	}

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

	@Override
	public int getGroupCount() {
		// TODO Auto-generated method stub
		return groups.length;
	}

	@Override
	public long getGroupId(int groupPosition) {
		// TODO Auto-generated method stub
		return groupPosition;
	}

	@Override
	public View getGroupView(int groupPosition, boolean isExpanded,
			View convertView, ViewGroup parent) {
		TextView textView = getGenericView();
		textView.setText(getGroup(groupPosition).toString());

		return textView;
	}

	@Override
	public boolean hasStableIds() {
		// TODO Auto-generated method stub
		return true;
	}

	@Override
	public boolean isChildSelectable(int groupPosition, int childPosition) {
		// TODO Auto-generated method stub
		return true;
	}

	// 获取某一项的view的逻辑
	private TextView getGenericView() {
		AbsListView.LayoutParams lp = new AbsListView.LayoutParams(
				ViewGroup.LayoutParams.FILL_PARENT, 48);
		TextView textView = new TextView(mContext);
		textView.setLayoutParams(lp);
		textView.setGravity(Gravity.CENTER_VERTICAL | Gravity.LEFT);
		textView.setPadding(32, 0, 0, 0);
		return textView;
	}

}

运行的结果如下：

关注微信号：javalearns   随时随地学Java

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随时随地学Java