import android.app.ListActivity;import android.os.Bundle;import android.os.Handler;import android.view.Gravity;import android.view.View;import android.view.ViewGroup;import android.widget.AbsListView;import android.widget.BaseAdapter;import android.widget.ImageView;import android.widget.LinearLayout;import android.widget.ProgressBar;import android.widget.TextView;import android.widget.AbsListView.OnScrollListener;import android.widget.LinearLayout.LayoutParams;public class Test extends ListActivity implements OnScrollListener { Aleph0 adapter = new Aleph0(); int lastItem = 0; int mProgressStatus = 0; private Handler mHandler = new Handler(); ProgressBar progressBar; protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); LinearLayout searchLayout = new LinearLayout(this); searchLayout.setOrientation(LinearLayout.HORIZONTAL); progressBar = new ProgressBar(this); progressBar.setPadding(0, 0, 15, 0); searchLayout.addView(progressBar,new LinearLayout.LayoutParams( LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT )); TextView textView = new TextView(this); textView.setText("加载中..."); textView.setGravity(Gravity.CENTER_VERTICAL); searchLayout.addView(textView,new LinearLayout.LayoutParams( LinearLayout.LayoutParams.FILL_PARENT, LinearLayout.LayoutParams.FILL_PARENT )); searchLayout.setGravity(Gravity.CENTER); LinearLayout loadingLayout = new LinearLayout(this); loadingLayout.addView(searchLayout,new LinearLayout.LayoutParams( LinearLayout.LayoutParams.WRAP_CONTENT, LinearLayout.LayoutParams.WRAP_CONTENT )); loadingLayout.setGravity(Gravity.CENTER); getListView().addFooterView(loadingLayout); // Start lengthy operation in a background thread// new Thread(new Runnable() {// public void run() {// while (mProgressStatus < 100) {//// // Update the progress bar// mHandler.post(new Runnable() {// public void run() {// progressBar.setProgress(mProgressStatus);// }// });// }// }// }).start(); registerForContextMenu(getListView()); setListAdapter(adapter); getListView().setOnScrollListener(this); } public void onScroll(AbsListView v, int firstVisibleItem, int visibleItemCount, int totalItemCount) { lastItem = firstVisibleItem + visibleItemCount - 1 ; System.out.println("lastItem:" + lastItem); } public void onScrollStateChanged(AbsListView v, int state) { if(lastItem == adapter.count && state == OnScrollListener.SCROLL_STATE_IDLE){ adapter.count += 10; adapter.notifyDataSetChanged(); }// if(state == OnScrollListener.SCROLL_STATE_IDLE ) {// adapter.count += 10;// adapter.notifyDataSetChanged();// } } class Aleph0 extends BaseAdapter { int count = 10; public int getCount() { return count; } public Object getItem(int pos) { return pos; } public long getItemId(int pos) { return pos; } public View getView(int pos, View v, ViewGroup p) { TextView view = new TextView(Test.this); view.setText("entry " + pos); view.setHeight(90); return view; } }}
OnScrollListener回调分析
如果adapter中的数据量很大的时候,在加载listview时会出现卡顿的现象。这是会让用户抓狂!最好的解决办法就是先加载一定数量的数据,然后在最下方提示正在加载! 动态加载就是把放入adapter中的数据分好几次加载。在用户拖动listview时再加载一定的数据,和sina微博的客户端类似。 给listview添加OnScrollListener监听事件默认会覆盖下面两个方法: new OnScrollListener() { boolean isLastRow = false; @Override public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) { //滚动时一直回调,直到停止滚动时才停止回调。单击时回调一次。 //firstVisibleItem:当前能看见的第一个列表项ID(从0开始) //visibleItemCount:当前能看见的列表项个数(小半个也算) //totalItemCount:列表项共数 //判断是否滚到最后一行 if (firstVisibleItem + visibleItemCount == totalItemCount && totalItemCount > 0) { isLastRow = true; } } @Override public void onScrollStateChanged(AbsListView view, int scrollState) { //正在滚动时回调,回调2-3次,手指没抛则回调2次。scrollState = 2的这次不回调 //回调顺序如下 //第1次:scrollState = SCROLL_STATE_TOUCH_SCROLL(1) 正在滚动 //第2次:scrollState = SCROLL_STATE_FLING(2) 手指做了抛的动作(手指离开屏幕前,用力滑了一下) //第3次:scrollState = SCROLL_STATE_IDLE(0) 停止滚动 //当屏幕停止滚动时为0;当屏幕滚动且用户使用的触碰或手指还在屏幕上时为1; //由于用户的操作,屏幕产生惯性滑动时为2 //当滚到最后一行且停止滚动时,执行加载 if (isLastRow && scrollState == AbsListView.OnScrollListener.SCROLL_STATE_IDLE) { //加载元素 ...... isLastRow = false; } } }转载于:https://www.cnblogs.com/SZ2015/p/4640558.html
相关资源:android gridview分页和滑动效果