android-drop-down refresh

1: Define a ListView control first.

2: Define the template view:

3: Define the view of the bottom view:

4: Write the source code to achieve the effect of the drop-down refresh:

Package Com.huanglinbin.finsh;import Java.util.arraylist;import Java.util.hashmap;import java.util.List;import Java.util.map;import Android.app.activity;import Android.os.bundle;import Android.os.handler;import Android.view.view;import Android.view.view.onclicklistener;import Android.widget.abslistview;import Android.widget.abslistview.onscrolllistener;import Android.widget.button;import Android.widget.ListView;import Android.widget.progressbar;import Android.widget.simpleadapter;import Android.widget.toast;public Class Mainactivity extends Activity implements Onscrolllistener {//privatization attribute. Private Simpleadapter sa;private ListView lv;//listviewprivate button but;//buttons private ProgressBar pb;//load bar Private list& Lt Map<string,object>> list;//The view of the bottom view of the collection//listview. Private View moreview;//Async loader. Private Handler handler;//Sets the maximum number of loads that are not loaded when they are exceeded. private int maxnum;//The last visible entry index.    private int lastvisibleindex; @Override protected void OnCreate (Bundle savedinstancestate) {super.oncreate (sAvedinstancestate);                Setcontentview (R.layout.activity_main);        Set the maximum number of data (equivalent to all data in the database) Maxnum = 50;        You first need to find the ListView control.        LV = (ListView) Findviewbyid (R.ID.LISTVIEW1);        The view of the bottom view is instantiated first.                Moreview = Getlayoutinflater (). Inflate (R.layout.but,null);        Initializes the data.        List = new arraylist<map<string,object>> ();        Simulate the database.        for (int i=0;i<20;i++) {map<string,object> Map = new hashmap<string, object> ();        Map.put ("TV1", "section" +i+ "title");        Map.put ("TV2", "section" +i+ "Contents");        List.add (map);        }//Instantiate emulator. SA = new Simpleadapter (mainactivity.this, List, R.layout.item, new string[]{"TV1", "TV2"}, New        INT[]{R.ID.TV1,R.ID.TV2}); Loads the view at the bottom of the view.        Note Be sure to setadapter before loading the emulator.        Lv.addfooterview (Moreview);                Lv.setadapter (SA);        A listener event that binds the ListView to a scroll.         Lv.setonscrolllistener (Mainactivity.this);      Gets the button.        but = (Button) Findviewbyid (r.id.but);         PB = (ProgressBar) Findviewbyid (R.ID.PB);        The asynchronous loader.              Handler = new Handler ();       A listener event that binds the button to a fixed point. /* But.setonclicklistener (New Onclicklistener () {@Overridepublic void OnClick (View v) {//shows the progress bar. Pb.setvisibility (view.visible);//Displays the button as not visible. But.setvisibility (View.gone);//The loading of asynchronous data here. (Parameter 1:new run control, Parameter 2: Time of Asynchronous load) handler.postdelayed (new Runnable () {@Overridepublic void Run () {//Load more data. Lostmove ();//The progress bar is displayed. Pb.setvisibility (view.visible);//Displays the button as not visible. But.setvisibility (View.gone);//Notifies the ListView to refresh the data. Sa.notifydatasetchanged ();}},2000);});    */}//define a method to load data each time.    private void Lostmove () {//Gets the data in the adapter.    int count = Sa.getcount ();    Judgment when the data is not being loaded.    if (count+5<maxnum) {//Load data 5 each time.    for (int i=count;i<count+5;i++) {map<string,object> map1 = new hashmap<string, object> ();    Map1.put ("TV1", "section" +i+ "title");    Map1.put ("TV2", "section" +i+ "Contents");    List.add (MAP1); }   }else{//Data loading is less than 5 data load.    for (int j=count;j<maxnum;j++) {map<string,object> map1 = new hashmap<string, object> ();    Map1.put ("TV1", "section" +j+ "title");    Map1.put ("TV2", "section" +j+ "Contents");    List.add (MAP1); }}} public void Onscroll (Abslistview view, int firstvisibleitem,int visibleitemcount, int totalitemcount) {//Scroll The callback is stopped until the scroll is stopped. Callback once when clicked. Firstvisibleitem: The first list item ID currently visible (starting at 0)//visibleitemcount: The number of list items currently visible (small half is counted)//totalitemcount: List items total number// Calculates the index of the last visible entry Lastvisibleindex = firstvisibleitem+visibleitemcount-1;//The view of the ListView at the bottom is removed when all the list items are equal to the maximum number of data. if (Totalitemcount = = maxnum+1) {//Remove bottom ListView. Lv.removefooterview (Moreview); Toast.maketext (Mainactivity.this, "The data is all loaded! ", Toast.length_short). Show ();}} public void onscrollstatechanged (Abslistview view, int scrollstate) {//slip to the bottom of the load, Determine if the ListView has stopped scrolling and the last visible entry equals the adapter entry if (scrollstate==onscrolllistener.scroll_state_idle&& Lastvisibleindex==sa.getcount ()) {//The progress bar is displayed. Pb.setvisibility (view.visible); handLer.postdelayed (New Runnable () {@Overridepublic void Run () {//Load more data. Lostmove ();//The progress bar is displayed. Pb.setvisibility (view.visible);//Notifies the ListView to refresh the data.       Sa.notifydatasetchanged ();}},2000);}} }

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android-drop-down refresh