Pull-down refresh principle ., Pull-down refresh Principle

Pull-down refresh principle ., Pull-down refresh Principle

1 package com. lixu. listviewrefresh; 2 3 import java. util. arrayList; 4 5 import android. app. activity; 6 import android. OS. bundle; 7 import android. widget. absListView; 8 import android. widget. absListView. onScrollListener; 9 import android. widget. arrayAdapter; 10 import android. widget. listView; 11 12 public class MainActivity extends Activity {13 private ArrayList <String> data; 14 private ArrayAdapter <String> mMyAdapter; 15 16 @ Override17 protected void onCreate (Bundle savedInstanceState) {18 super. onCreate (savedInstanceState); 19 setContentView (R. layout. activity_main); 20 21 data = new ArrayList <String> (); 22 23 for (int I = 0; I <30; I ++) {24 data. add ("Test Data" + I); 25} 26 27 ListView lv = (ListView) findViewById (R. id. listview); 28 29 mMyAdapter = new ArrayAdapter <String> (this, android. r. layout. simple_list_item_1, data); 30 31 lv. setAdapter (mMyAdapter); 32 33 lv. setOnScrollListener (new OnScrollListener () {34 private int firstVisibleItem; 35 private int visibleItemCount; 36 private int totalItemCount; 37 38 @ override 39 public void onScrollStateChanged (AbsListView view, int scrollState) {40 // judge 41 if (OnScrollListener when sliding stops. SCROLL_STATE_IDLE = scrollState) {42 43 if (firstVisibleItem = 0) {44 45 data. add (0, "add header data" + (totalItemCount + 1); 46 47 mMyAdapter. notifyDataSetChanged (); 48 49} 50} 51 52 if (OnScrollListener. SCROLL_STATE_IDLE = scrollState) {53 54 if (firstVisibleItem + visibleItemCount) = totalItemCount) {55 56 data. add ("add tail data" + (totalItemCount + 1); 57 58 mMyAdapter. notifyDataSetChanged (); 59 60} 61} 62 63} 64 65 @ Override66 public void onScroll (AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {67 68 this. firstVisibleItem = firstVisibleItem; 69 this. visibleItemCount = visibleItemCount; 70 this. totalItemCount = totalItemCount; 71 72} 73}); 74 75} 76 77}

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