Android up and down sliding view implementation

Put the code for this custom view first,

Package com.example.viewpagervertical;

Import Android.content.Context;

Import Android.util.AttributeSet;

Import Android.util.Log;

Import android.view.MotionEvent;

Import Android.view.VelocityTracker;

Import Android.view.View;

Import Android.view.ViewGroup;

Import Android.view.animation.Interpolator;

Import Android.widget.Scroller;

Import Android.widget.Toast;

/**

* To achieve the effect of sliding up and down, mainly using the screen coordinate system and scroll bar

* @author Administrator

*

*/

public class Verticalpager extends viewgroup{

private Scroller Mscroller; scroll bar

private Context mcontext;

Private final static int rate = 5; Rate Standard

private final static int DISTANCE = 300;//the distance to scroll

Private Velocitytracker mvelocitytracker;//This class allows you to calculate the speed

Public Verticalpager (context context, AttributeSet Attrs) {

Super (context, attrs);

This.mcontext=context;

mscroller=new Scroller (context);

}

@Override

protected void OnLayout (Boolean changed, int l, int t, int r, int b) {

int totalheight=0;

int Count=getchildcount ();

for (int i=0;i<count;i++) {

View Childview=getchildat (i);

childview.layout (L, Totalheight, R, Totalheight+b);

totalheight+=b;

}

}

@Override

protected void onmeasure (int widthmeasurespec, int heightmeasurespec) {

int width=measurespec.getsize (WIDTHMEASURESPEC);

int height=measurespec.getsize (HEIGHTMEASURESPEC);

int Count=getchildcount ();

for (int i=0;i<count;i++) {

Getchildat (i). Measure (width, height);

}

setmeasureddimension (width, height);

}

private int mlastmotiony;

@Override

Public boolean ontouchevent (Motionevent event) {

if (mvelocitytracker==null) {

Mvelocitytracker=velocitytracker.obtain ();

}

mvelocitytracker.addmovement (event);

int action=event.getaction ();

float y=event.gety ();

Switch (action) {

Case Motionevent.action_down:

if (!mscroller.isfinished ()) {

mscroller.abortanimation ();

}

mlastmotiony= (int) y;

log.d ("Montion", "" +getscrolly ());

break;

Case Motionevent.action_move:

int deltay= (int) (MLASTMOTIONY-Y);

Scrollby (0,deltay);

invalidate ();

mlastmotiony= (int) y;

break;

Case MOTIONEVENT.ACTION_UP:

if (mvelocitytracker!=null) {

mvelocitytracker.recycle ();

Mvelocitytracker=null;

// }

mvelocitytracker.computecurrentvelocity (1, 1000); Unit is 1 description, one second per pixel, maximum value is 1000

Float vy = mvelocitytracker.getyvelocity (); VY represents the y-axis direction of the rate

log.i ("Test", "Velocitytraker:" +mvelocitytracker.getyvelocity ());

if (getscrolly () <0) {

mscroller.startscroll (0,-distance, 0, DISTANCE);

}else if (getscrolly () > (GetHeight () * (Getchildcount ()-1)) {

View Lastview=getchildat (Getchildcount ()-1);

Mscroller.startscroll (0,lastview.gettop () +distance, 0,-distance);

}else{

int position=getscrolly ()/getheight ();

View positionview = null;

if (vy<-rate) {//Slide

Positionview=getchildat (position+1);

mscroller.startscroll (0, Positionview.gettop ()-distance, 0, +distance);

}else if (vy>rate) {//Slide up

Positionview=getchildat (position);

mscroller.startscroll (0, Positionview.gettop ()-distance, 0, +distance);

}else {

int mod=getscrolly ()%getheight ();

if (Mod>getheight ()/2) {

Positionview=getchildat (position+1);

mscroller.startscroll (0, Positionview.gettop ()-distance, 0, +distance);

}else{

Positionview=getchildat (position);

mscroller.startscroll (0, Positionview.gettop () +distance, 0,-distance);

}

}

}

invalidate ();

break;

}

return true; Returns true to indicate that the event was consumed by this view

}

@Override

public void Computescroll () {

Super.computescroll ();

if (Mscroller.computescrolloffset ()) {

scrollTo (0, Mscroller.getcurry ());

}

}

}

Then the layout file Activity_main.xml:

<?xml version= "1.0" encoding= "UTF-8"?>

<linearlayout xmlns:android= "Http://schemas.android.com/apk/res/android"

Android:layout_width= "Fill_parent"

android:layout_height= "Fill_parent"

android:orientation= "Vertical" >

<com.example.viewpagervertical.verticalpager

Android:id= "@+id/vertypager1"

Android:layout_width= "Fill_parent"

android:layout_height= "Fill_parent" >

<textview

android:background= "@drawable/iv_guide1"

Android:id= "@+id/textview1"

Android:layout_width= "Match_parent"

android:layout_height= "100DP"

android:text= "TextView1111"/>

<textview

android:background= "@drawable/iv_guide2"

Android:id= "@+id/textview2"

Android:layout_width= "Fill_parent"

android:layout_height= "100DP"

android:text= "TextView2222"/>

<textview

android:background= "@drawable/iv_guide3"

Android:id= "@+id/textview3"

Android:layout_width= "Fill_parent"

android:layout_height= "100DP"

android:text= "TextView2222"/>

<textview

android:background= "@drawable/iv_guide4"

Android:id= "@+id/textview4"

Android:layout_width= "Fill_parent"

android:layout_height= "100DP"

android:text= "TextView2222"/>

</com.example.viewpagervertical.VerticalPager>

</LinearLayout>

Mainactivity.java do not move, the eclipse is created by the line.

Android up and down sliding view implementation