Android controls ListView scroll up and down via code

This article describes a way to control how the ListView scrolls up and down through code.

First:

Pressing the button triggers the ListView to scroll or stop.

It is not difficult to implement this function, the following is the main code Mainactivity.java

Package Cn.guet.levide;import Android.app.activity;import Android.os.bundle;import android.os.handler;import Android.os.message;import Android.view.view;import Android.view.view.onclicklistener;import Android.widget.Button Import Android.widget.listview;public class Mainactivity extends Activity implements Onclicklistener {private Button Btn_up, Btn_down, btn_stop; Three buttons private ListView listview;private Adapter Adapter; @Overridepublic void OnCreate (Bundle savedinstancestate) { Super.oncreate (savedinstancestate); Setcontentview (R.layout.main); FindBy (); init ();} private void Init () {Btn_up.setonclicklistener (this); Btn_down.setonclicklistener (this); Btn_ Stop.setonclicklistener (this), adapter = new adapter (this); Listview.setadapter (adapter);} private void FindBy () {btn_up = (button) Findviewbyid (r.id.btn_scroll_up); btn_down = (Button) Findviewbyid (r.id.btn_ Scroll_down); btn_stop = (Button) Findviewbyid (r.id.btn_scroll_stop); listview = (ListView) Findviewbyid (R.id.listview );} @Overridepublic voidOnClick (View v) {switch (V.getid ()) {case R.id.btn_scroll_down:listscrolldown (); Break;case r.id.btn_scroll_up: Listscrollup (); break;case R.id.btn_scroll_stop:listscrolloff (); break;}} Handler Handler = new Handler () {@Overridepublic void Handlemessage (Message msg) {handler.removecallbacks (Run_scroll_ down); Handler.removecallbacks (run_scroll_up);}};/ * * * scroll up */public void Listscrollup () {Listscrolloff (); handler.postdelayed (run_scroll_up, 0);} /** * Scroll down */public void Listscrolldown () {Listscrolloff (); handler.postdelayed (Run_scroll_down, 0);} /** * Stop scrolling */public void Listscrolloff () {handler.removecallbacks (Run_scroll_down); Handler.removecallbacks (Run_ SCROLL_UP);} Runnable run_scroll_up = new Runnable () {@Overridepublic void run () {/** * public void Smoothscrollby (int distance, int d uration) * * Added in API level 8 smoothly scroll by distance pixels over duration milliseconds. * * Parameters * distance distance to scroll in pixels. * Duration duration of the scroll animation in MIlliseconds. */listview.smoothscrollby (1); Handler.postdelayed (run_scroll_up, 10);}}; Runnable Run_scroll_down = new Runnable () {@Overridepublic void run () {Listview.smoothscrollby (-1, 10); Handler.postdelayed (Run_scroll_down, 10);}};}

The Smoothscrollby method is used to implement the ListView position change.

public void Smoothscrollby (int distance, int. duration)     smoothly scroll by distance pixels over duration milliseconds. Parameters    distance  distance to scroll in pixels.     Duration  duration of the scroll animation in milliseconds.  

Project Source:

Android ListView Code controls Move up and down

Android controls ListView scroll up and down via code