本文实例讲述了android自定义viewpager的方法。分享给大家供大家参考，具体如下：
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package com.rong.activity;
import android.content.context;
import android.graphics.color;
import android.util.attributeset;
import android.view.motionevent;
import android.view.velocitytracker;
import android.view.view;
import android.view.viewgroup;
import android.widget.linearlayout;
import android.widget.scroller;
public class customviewpager extends viewgroup {
private context mcontext;
private int screenwidth;
private int screenhight;
private int lastmovex = 0;
private velocitytracker velocitytracker;
private int max_velocity=600;
private int curscreen=0;
private scroller scroller;
public customviewpager(context context) {
super(context);
mcontext = context;
initview();
}
public customviewpager(context context, attributeset attrs) {
super(context, attrs);
mcontext = context;
initview();
}
public customviewpager(context context, attributeset attrs, int defstyle) {
super(context, attrs, defstyle);
mcontext = context;
initview();
}
@override
public boolean ontouchevent(motionevent event) {
if (velocitytracker == null) {
velocitytracker = velocitytracker.obtain();
}
velocitytracker.addmovement(event);
int x = (int) event.getx();
switch (event.getaction()) {
case motionevent.action_down:
lastmovex = x;
break;
case motionevent.action_move:
int dis = lastmovex - x;
scrollby(dis, 0);
lastmovex = x;
break;
case motionevent.action_up:
velocitytracker.computecurrentvelocity(1000);
int velocityx=(int)velocitytracker.getxvelocity();
if(velocityx>max_velocity&&curscreen>0){
jump2screen(curscreen-1);
}else if(velocityx<-max_velocity&&curscreen<getchildcount()-1){
jump2screen(curscreen+1);
}else{
int screen=(getscrollx()+screenwidth/2)/screenwidth;
jump2screen(screen);
}
if (velocitytracker != null) {
velocitytracker.recycle();
velocitytracker = null;
}
break;
}
return true;
}
/**
* 跳转到指定screen
* @param screen
*/
public void jump2screen(int screen){
curscreen=screen;
if(curscreen>getchildcount()-1){
curscreen=getchildcount()-1;
}
int dis=curscreen*screenwidth-getscrollx();
scroller.startscroll(getscrollx(), 0, dis, 0);
invalidate();
}
@override
public void computescroll() {
if(scroller.computescrolloffset()){
scrollto(scroller.getcurrx(), 0);
postinvalidate();
}
}
public void initview() {
scroller=new scroller(mcontext);
linearlayout layout1 = new linearlayout(getcontext());
layout1.setbackgroundcolor(color.red);
addview(layout1);
linearlayout layout2 = new linearlayout(getcontext());
layout2.setbackgroundcolor(color.green);
addview(layout2);
linearlayout layout3 = new linearlayout(getcontext());
layout3.setbackgroundcolor(color.blue);
addview(layout3);
}
@override
protected void onmeasure(int widthmeasurespec, int heightmeasurespec) {
super.onmeasure(widthmeasurespec, heightmeasurespec);
screenwidth = measurespec.getsize(widthmeasurespec);
screenhight = measurespec.getsize(heightmeasurespec);
setmeasureddimension(screenwidth, screenhight);
for (int i = 0; i < getchildcount(); i++) {
view view = getchildat(i);
view.measure(screenwidth, screenhight);
}
}
@override
protected void onlayout(boolean changed, int l, int t, int r, int b) {
int leftwidth = 0;
for (int i = 0; i < getchildcount(); i++) {
view view = getchildat(i);
view.layout(leftwidth, 0, leftwidth + screenwidth, screenhight);
leftwidth = leftwidth + screenwidth;
}
}
}
更多关于android相关内容感兴趣的读者可查看本站专题：《android开发入门与进阶教程》、《android基本组件用法总结》、《android视图view技巧总结》、《android布局layout技巧总结》及《android控件用法总结》
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