本文实例讲述了Android使用ListView实现下拉刷新及上拉显示更多的方法。分享给大家供大家参考,具体如下:
今天得需求是做listview+上下拉动在header和footer显示progressdialog,但不影响用户操作
直接上代码,我已经加上注释了,自己看。
package com.stay.main; import java.net.HttpURLConnection; import java.util.ArrayList; import java.util.HashMap; import org.json.JSONObject; import android.app.Activity; import android.app.ProgressDialog; import android.graphics.drawable.Drawable; import android.os.Bundle; import android.os.Handler; import android.os.HandlerThread; import android.os.Looper; import android.os.Message; import android.view.LayoutInflater; import android.view.View; import android.widget.AbsListView; import android.widget.AbsListView.OnScrollListener; import android.widget.Button; import android.widget.LinearLayout; import android.widget.ListView; import android.widget.RelativeLayout; import android.widget.TextView; import com.stay.wifi.R; /** * @author Stay * 动态加载listview数据,上拉 刷新,下拉 更多 */ public class ListViewActivity extends Activity implements OnScrollListener { private static final int LOAD = 0; private static final int ERROR = 0; private static final int MEMBER = 1; private static final int LOADED = 2; private static final int DIALOG = 3; private static final int FULL = 4; private NearbyAdapter adapter; private ListView nearby_lv; private RelativeLayout nearby_lv_header; private Button list_bottom_btn; private LinearLayout list_bottom_linear; private TextView bottom_progress_text; private RelativeLayout nearby_lv_footer; private Button list_header_btn; private LinearLayout list_header_linear; private TextView heard_progress_text; private ArrayList<JSONObject> nearby_data = new ArrayList<JSONObject>(); private int lastItem; private HashMap<String, Drawable> imageCache; private com.stay.main.ListViewActivity.MyHandler myHandler; private ProgressDialog dialog; private int curPage = 1; private boolean isMember = false; private int firstItem; public int count; /** Called when the activity is first created. */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); initView(); myHandler.sendEmptyMessage(LOAD); } @Override public void onScrollStateChanged(AbsListView view, int scrollState) { DebugUtil.debug("onScrollStateChanged"); //当滚动停止且滚动的总数等于数据的总数,去加载 if (lastItem == count && scrollState == SCROLL_STATE_IDLE) { DebugUtil.debug("onScrollStateChanged--------next"); if (curPage == 4 && !isMember) { DebugUtil.show(this, "您不是正式会员,请申请正式会员,"); list_bottom_linear.setVisibility(View.GONE); } else { //加载数据 myHandler.sendEmptyMessage(LOAD); } return; } //当往上拉时更新数据,将data清空然后去重新加载 if (firstItem == 0 && scrollState == SCROLL_STATE_IDLE) { DebugUtil.debug("onScrollStateChanged--------refresh"); curPage = 0; myHandler.sendEmptyMessage(LOAD); } } @Override public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) { DebugUtil.debug("firstVisibleItem=" + firstVisibleItem); DebugUtil.debug("visibleItemCount=" + visibleItemCount); DebugUtil.debug("totalItemCount=" + totalItemCount); //这里要减二,因为我加了header footer lastItem = firstVisibleItem + visibleItemCount - 2; firstItem = firstVisibleItem; } public int getData() { try { HttpURLConnection conn = DownloadUtil.download(url//自己写咯); ArrayList<JSONObject> temp = JSONUtil.streamToJsonList(conn.getInputStream()); if (curPage == 0 && nearby_data.size() > 0) { nearby_data.clear(); count = 0; } if (temp != null && temp.size() > 0) { count += temp.size(); nearby_data.addAll(temp); DebugUtil.debug("nearby_data.size()="+nearby_data.size()); } else { return FULL; } return LOADED; } catch (Exception e) { return ERROR; } } private Handler handler = new Handler() { @Override public void handleMessage(Message msg) { super.handleMessage(msg); switch (msg.what) { case DIALOG: list_bottom_linear.setVisibility(View.VISIBLE); list_header_linear.setVisibility(View.VISIBLE); break; case LOADED: list_bottom_linear.setVisibility(View.GONE); list_header_linear.setVisibility(View.GONE); curPage++; adapter.notifyDataSetChanged(); break; case ERROR: DebugUtil.debug("error,missing data"); break; case MEMBER: DebugUtil.debug("you must regist formal member"); break; default: break; } } }; //创建子线程加载数据,然后更新 private class MyHandler extends Handler { private int status; public MyHandler(Looper looper) { super(looper); } @Override public void handleMessage(Message msg) { synchronized (this) { switch (msg.what) { case LOAD:// get data from server handler.sendEmptyMessage(DIALOG);//显示等待框 status = getData(); handler.sendEmptyMessageDelayed(status, 1000); break; default: break; } } } } public void initView() { imageCache = new HashMap<String, Drawable>(); HandlerThread handlerThread = new HandlerThread("nearby"); // 在使用HandlerThread的getLooper()方法之前,必须先调用该类的start(); handlerThread.start(); myHandler = new MyHandler(handlerThread.getLooper()); nearby_lv = (ListView) findViewById(R.id.nearby_lv); nearby_lv_footer = (RelativeLayout) LayoutInflater.from(ListViewActivity.this).inflate(R.layout.nearby_lv_header, null); list_bottom_btn = (Button) nearby_lv_footer.findViewById(R.id.list_bottom_btn); list_bottom_linear = (LinearLayout) nearby_lv_footer.findViewById(R.id.list_bottom_linear); bottom_progress_text = (TextView) nearby_lv_footer.findViewById(R.id.progress_text); nearby_lv_header = (RelativeLayout) LayoutInflater.from(ListViewActivity.this).inflate(R.layout.nearby_lv_header, null); list_header_btn = (Button) nearby_lv_header.findViewById(R.id.list_bottom_btn); list_header_linear = (LinearLayout) nearby_lv_header.findViewById(R.id.list_bottom_linear); heard_progress_text = (TextView) nearby_lv_header.findViewById(R.id.progress_text); list_header_btn.setText("刷新"); list_bottom_btn.setText("更多"); list_header_linear.setVisibility(View.GONE); nearby_lv.addHeaderView(nearby_lv_header); nearby_lv.addFooterView(nearby_lv_footer); // list_header_btn.setOnClickListener(header_click); adapter = new NearbyAdapter(ListViewActivity.this, nearby_data); nearby_lv.setAdapter(adapter); nearby_lv.setOnScrollListener(ListViewActivity.this); } }
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