Android ListView pulls to the top/bottom, like a rubber band resilient rebound reset



"Android ListView pulls to the top/bottom, like a rubber band resilient rebound reset"

The android itself's ListView pulls to the top or bottom will have a "flash" effect on the top/bottom edge gap, suggesting that the ListView is already at the top/bottom and cannot be moved anymore.
This is an interactive design that Android native ListView pulls to the top/bottom. There are many options for interactive design. Android 5.0 transforms this interactive design of the ListView into a "rippling halo".
Among the many interactive designs, one interaction design is this: When the ListView pulls to the top or bottom, the ListView will look like a rubber band, and the ListView has a damping effect, and when the user releases the ListView, The ListView automatically bounces back to the top/bottom as elastic as a rubber band.
This interactive effect is achieved on Android, and the Method Overscrollby () that overrides the ListView can be implemented.
Now give an example, step by step implementation.
First, I need to write a zhangphillistview that inherits from Android's ListView:

Package Zhangphil.listview;import Android.annotation.suppresslint;import Android.content.context;import Android.util.attributeset;import Android.util.displaymetrics;import Android.widget.listview;public Class Zhangphillistview extends ListView {//This value control can pull the ListView out of the distance from the top or bottom. private static final int max_overscroll_y = 200;private Context mcontext;private int newmaxoverscrolly;public Zhangphilli Stview (Context context) {super (context); this.mcontext = Context;init ();} Public Zhangphillistview (context context, AttributeSet Attrs) {Super (context, attrs); this.mcontext = Context;init ();} /* Public Zhangphillistview (context context, AttributeSet attrs, int * defstyle) {Super (context, attrs, Defstyle); . Mcontext = Context; * Init (); } */private void init () {Displaymetrics metrics = mcontext.getresources (). Getdisplaymetrics (); float density = metrics.density;newmaxoverscrolly = (int) (density * max_overscroll_y);} The most critical place. Support to SDK8 need to add @suppresslint ("Newapi"). @SuppressLint ("Newapi") @Overrideprotected boolean Overscrollby (int deltax, int deltay, int scrollx,int scrolly, int scrollrangex, int scrollrangey,int ma XOVERSCROLLX, int maxoverscrolly, Boolean istouchevent) {return Super.overscrollby (DeltaX, DeltaY, Scrollx, ScrollY, Scrollrangex, Scrollrangey, MAXOVERSCROLLX, newmaxoverscrolly,istouchevent);}}

Then use it directly in my layout file activity_main.xml like a ListView using Android:

<linearlayout xmlns:android= "http://schemas.android.com/apk/res/android"    android:layout_width= "Match_ Parent "    android:layout_height=" match_parent "    android:orientation=" vertical ">        < Zhangphil.listview.ZhangPhilListView        android:id= "@+id/listview"        android:layout_width= "Match_parent"        android:layout_height= "match_parent"/>    </LinearLayout>

Test:

Package Zhangphil.listview;import Android.support.v7.app.actionbaractivity;import Android.widget.ArrayAdapter; Import Android.widget.listview;import Android.os.bundle;public class Mainactivity extends Actionbaractivity {@ overrideprotected void OnCreate (Bundle savedinstancestate) {super.oncreate (savedinstancestate); Setcontentview ( R.layout.activity_main); ListView LV = (ListView) Findviewbyid (R.id.listview);//test data set. string[] data = new String[50];for (int i = 0; i < data.length; i++) {Data[i] = i + "";} arrayadapter<string> adapter = new Arrayadapter<string> (this,android. R.layout.simple_list_item_1, Android. R.ID.TEXT1, data); Lv.setadapter (adapter);}}

Copyright NOTICE: This article for Bo Master original article, without Bo Master permission not reproduced.

Android ListView pulls to the top/bottom, like a rubber band resilient rebound reset