android 中listview滑动加载的简单demo

在使用listview时，滑动加载可以提高效率，增加用户体验。

主要用到一个OnScrollListener

   /**
         * The view is not scrolling. Note navigating the list using the trackball counts as
         * being in the idle state since these transitions are not animated.
         */
        public static int SCROLL_STATE_IDLE = 0;

        /**
         * The user is scrolling using touch, and their finger is still on the screen
         */
        public static int SCROLL_STATE_TOUCH_SCROLL = 1;

        /**
         * The user had previously been scrolling using touch and had performed a fling. The
         * animation is now coasting to a stop
         */
        public static int SCROLL_STATE_FLING = 2;

        /**
         * Callback method to be invoked while the list view or grid view is being scrolled. If the
         * view is being scrolled, this method will be called before the next frame of the scroll is
         * rendered. In particular, it will be called before any calls to
         * {@link Adapter#getView(int, View, ViewGroup)}.
         *
         * @param view The view whose scroll state is being reported
         *
         * @param scrollState The current scroll state. One of {@link #SCROLL_STATE_IDLE},
         * {@link #SCROLL_STATE_TOUCH_SCROLL} or {@link #SCROLL_STATE_IDLE}.
         */
        public void onScrollStateChanged(AbsListView view, int scrollState);

        /**
         * Callback method to be invoked when the list or grid has been scrolled. This will be
         * called after the scroll has completed
         * @param view The view whose scroll state is being reported
         * @param firstVisibleItem the index of the first visible cell (ignore if
         *        visibleItemCount == 0)
         * @param visibleItemCount the number of visible cells
         * @param totalItemCount the number of items in the list adaptor
         */
        public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount,
                int totalItemCount);

package com.nico.listviewload;

import java.util.ArrayList;
import java.util.List;

import com.nico.bean.MsgInfo;

import android.app.Activity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AbsListView;
import android.widget.BaseAdapter;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.AbsListView.OnScrollListener;

public class MainActivity extends Activity {

	List<MsgInfo> infoList = null;
	private LayoutInflater inflater = null;
	private ListView listview = null;
	private myAdapter adapter = null;
	private LinearLayout ftview = null;

	private Handler handler = new Handler() {

		@Override
		public void handleMessage(Message msg) {
			super.handleMessage(msg);
			switch (msg.what){
			
				case 1:
					 adapter.notifyDataSetChanged();
				try {
					Thread.sleep(2000l);
				} catch (InterruptedException e) {
					e.printStackTrace();
				}
				setAdapter();
					break;
			}
		}
	};

	/** Called when the activity is first created. */
	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
		inflater = this.getLayoutInflater();

		listview = (ListView) findViewById(R.id.listview);
		ftview = (LinearLayout) inflater.inflate(R.layout.ftview, null);

		listview.addFooterView(ftview, null, false);
		listview.setAdapter(new myAdapter());
		adapter = new myAdapter();

		ftview.setVisibility(View.VISIBLE);
		listview.setOnScrollListener(new OnScrollListener() {

			@Override
			public void onScrollStateChanged(AbsListView view, int scrollState) {

				if (scrollState == SCROLL_STATE_IDLE
						&& view.getLastVisiblePosition() == view.getCount() - 1)

				{
					handler.sendEmptyMessage(1);
				}
			}

			@Override
			public void onScroll(AbsListView view, int firstVisibleItem,
					int visibleItemCount, int totalItemCount) {

			}
		});
	}

	public List<MsgInfo> getList() {
		List<MsgInfo> infoList = new ArrayList<MsgInfo>();
		for (int i = 0; i < 7; i++) {
			MsgInfo info = new MsgInfo();
			info.id = i;
			info.detailinfo = "这是第" + i + "条信息";
			info.name = "第" + i + "项";
			info.size = 1024 * i;
			infoList.add(info);
		}
		return infoList;
	}

	public void setData() {

		infoList = getList();
	}

	public void setAdapter() {
		for (int i = 0; i < 7; i++) {
			MsgInfo info = new MsgInfo();
			info.id = i;
			info.detailinfo = "这是第" + i + "条信息";
			info.name = "第" + i + "项";
			info.size = 1024 * i;
			infoList.add(info);
		}

		adapter.notifyDataSetChanged();
	}

	public class myAdapter extends BaseAdapter {

		@Override
		public void notifyDataSetChanged() {
			if(ftview.getVisibility()==View.VISIBLE)
			{
				ftview.setVisibility(View.GONE);
			}
			else if(ftview.getVisibility()==View.GONE)
			{
				ftview.setVisibility(View.VISIBLE);
			}
			super.notifyDataSetChanged();
		}

		TextView name, detail, size;

		public myAdapter() {
			setData();
		}

		@Override
		public int getCount() {
			return infoList.size();
		}

		@Override
		public Object getItem(int position) {
			return infoList.get(position);
		}

		@Override
		public long getItemId(int position) {
			return position;
		}

		@Override
		public View getView(int position, View convertView, ViewGroup parent) {
			if (convertView == null) {
				convertView = inflater.inflate(R.layout.item, null, false);

			}
			name = (TextView) convertView.findViewById(R.id.name);
			detail = (TextView) convertView.findViewById(R.id.detail);
			size = (TextView) convertView.findViewById(R.id.size);
			name.setText(infoList.get(position).name);
			detail.setText(infoList.get(position).detailinfo);
			size.setText(infoList.get(position).size + "");
			return convertView;
		}
		
		
	}

	public class LoadAsyTask extends AsyncTask<String, String, String> {

		@Override
		protected String doInBackground(String... params) {

			for (int i = 0; i < 7; i++) {
				MsgInfo info = new MsgInfo();
				info.id = i;
				info.detailinfo = "这是第" + i + "条信息";
				info.name = "第" + i + "项";
				info.size = 1024 * i;
				infoList.add(info);
			}
			return null;
		}

		@Override
		protected void onPostExecute(String result) {
			super.onPostExecute(result);
		
			ftview.setVisibility(View.GONE);
			adapter.notifyDataSetChanged();
		}

	}
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
	android:layout_width="match_parent" android:layout_height="match_parent">
	<LinearLayout android:layout_width="fill_parent" android:gravity="center_horizontal"
		android:layout_height="wrap_content" android:layout_gravity="center_horizontal">
		<ImageView android:layout_width="50dip"
			android:layout_height="50dip" 
			android:src="@drawable/progressbar" android:id="@+id/pbdrawable" />
		<TextView android:layout_width="wrap_content"
			android:layout_height="wrap_content" android:text="请稍后..." android:id="@+id/pbtxt" />
	</LinearLayout>
</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>


<rotate xmlns:android="http://schemas.android.com/apk/res/android"
	android:pivotX="50%" android:pivotY="50%" android:fromDegrees="0"
	android:toDegrees="360">


	<shape android:shape="ring" android:innerRadiusRatio="3"
		android:thicknessRatio="8" android:useLevel="false">


		<gradient android:type="sweep" android:useLevel="false"
			android:startColor="#000000" android:centerColor="#FFFFFF"
			android:centerY="0.50" android:endColor="#000000" />

	</shape>

</rotate>