今天给大家介绍一下如何实现androd主页面的左右拖动效果。实现起来很简单，就是使用viewflipper来将您要来回拖动的view装在一起，然后与gesturedetector手势识别类来联动，确定要显示哪个view，加上一点点动画效果即可。比如当手指向左快速滑动时跳转到上一个view，手指向右快速滑动时跳转到下一个view，本例中使用图片作为各个view的页面，实现左右快速滑动显示不同的图片。
首先来看看我们的layout，如下所示：
<linearlayout android:layout_height="fill_parent" android:layout_width="fill_parent" android:orientation="vertical" xmlns:android="http://schemas.android.com/apk/res/android">
<viewflipper android:id="@+id/flipper" android:layout_below="@+id/cockpitlayout" android:layout_height="fill_parent" android:layout_width="fill_parent">
<include android:id="@+id/firstlayout" layout="@layout/first">
<include android:id="@+id/secondlayout" layout="@layout/second">
<include android:id="@+id/thirdlayout" layout="@layout/third">
<include android:id="@+id/fourthlayout" layout="@layout/fourth">
</include></include></include></include></viewflipper>
</linearlayout>
如上所示，在viewflipper中放置多个layout（接下来会在不同的layout中来回滑动），viewflipper在同一个页面就显示其中一个layout。viewflipper中的四个layout很简单，我们就放置一张图片，如下所示：
<linearlayout android:gravity="center_vertical" android:layout_height="fill_parent" android:layout_width="fill_parent" xmlns:android="http://schemas.android.com/apk/res/android">
<imageview android:layout_height="wrap_content" android:layout_width="wrap_content" android:src="@drawable/v1">
</imageview></linearlayout>
接下来我们来看看activity，我们的activity需要实现两个接口ongesturelistener,ontouchlistener。具体的代码如下所示，代码中都有相应的注释，这里就不再详述。
package com.ideasandroid.demo;
import android.app.activity;
import android.os.bundle;
import android.view.gesturedetector;
import android.view.motionevent;
import android.view.view;
import android.view.gesturedetector.ongesturelistener;
import android.view.view.ontouchlistener;
import android.view.animation.accelerateinterpolator;
import android.view.animation.animation;
import android.view.animation.translateanimation;
import android.widget.viewflipper;
public class viewflipperdemo extends activity implements ongesturelistener,ontouchlistener{
private viewflipper mflipper;
gesturedetector mgesturedetector;
private int mcurrentlayoutstate;
private static final int fling_min_distance = 100;
private static final int fling_min_velocity = 200;
@override
public void oncreate(bundle savedinstancestate) {
super.oncreate(savedinstancestate);
setcontentview(r.layout.main);
mflipper = (viewflipper) findviewbyid(r.id.flipper);
//注册一个用于手势识别的类
mgesturedetector = new gesturedetector(this);
//给mflipper设置一个listener
mflipper.setontouchlistener(this);
mcurrentlayoutstate = 0;
//允许长按住viewflipper,这样才能识别拖动等手势
mflipper.setlongclickable(true);
}
/**
* 此方法在本例中未用到，可以指定跳转到某个页面
* @param switchto
*/
public void switchlayoutstateto(int switchto) {
while (mcurrentlayoutstate != switchto) {
if (mcurrentlayoutstate > switchto) {
mcurrentlayoutstate--;
mflipper.setinanimation(infromleftanimation());
mflipper.setoutanimation(outtorightanimation());
mflipper.showprevious();
} else {
mcurrentlayoutstate++;
mflipper.setinanimation(infromrightanimation());
mflipper.setoutanimation(outtoleftanimation());
mflipper.shownext();
}
}
;
* 定义从右侧进入的动画效果
* @return
protected animation infromrightanimation() {
animation infromright = new translateanimation(
animation.relative_to_parent, +1.0f,
animation.relative_to_parent, 0.0f,
animation.relative_to_parent, 0.0f);
infromright.setduration(500);
infromright.setinterpolator(new accelerateinterpolator());
return infromright;
* 定义从左侧退出的动画效果
protected animation outtoleftanimation() {
animation outtoleft = new translateanimation(
animation.relative_to_parent, -1.0f,
outtoleft.setduration(500);
outtoleft.setinterpolator(new accelerateinterpolator());
return outtoleft;
* 定义从左侧进入的动画效果
protected animation infromleftanimation() {
animation infromleft = new translateanimation(
infromleft.setduration(500);
infromleft.setinterpolator(new accelerateinterpolator());
return infromleft;
* 定义从右侧退出时的动画效果
protected animation outtorightanimation() {
animation outtoright = new translateanimation(
outtoright.setduration(500);
outtoright.setinterpolator(new accelerateinterpolator());
return outtoright;
public boolean ondown(motionevent e) {
// todo auto-generated method stub
return false;
/*
* 用户按下触摸屏、快速移动后松开即触发这个事件
* e1：第1个action_down motionevent
* e2：最后一个action_move motionevent
* velocityx：x轴上的移动速度，像素/秒
* velocityy：y轴上的移动速度，像素/秒
* 触发条件 ：
* x轴的坐标位移大于fling_min_distance，且移动速度大于fling_min_velocity个像素/秒
public boolean onfling(motionevent e1, motionevent e2, float velocityx,
float velocityy) {
if (e1.getx() - e2.getx() > fling_min_distance
&& math.abs(velocityx) > fling_min_velocity) {
// 当像左侧滑动的时候
//设置view进入屏幕时候使用的动画
mflipper.setinanimation(infromrightanimation());
//设置view退出屏幕时候使用的动画
mflipper.setoutanimation(outtoleftanimation());
mflipper.shownext();
} else if (e2.getx() - e1.getx() > fling_min_distance
// 当像右侧滑动的时候
mflipper.setinanimation(infromleftanimation());
mflipper.setoutanimation(outtorightanimation());
mflipper.showprevious();
}
public void onlongpress(motionevent e) {
public boolean onscroll(motionevent e1, motionevent e2, float distancex,
float distancey) {
public void onshowpress(motionevent e) {
public boolean onsingletapup(motionevent e) {
public boolean ontouch(view v, motionevent event) {
// 一定要将触屏事件交给手势识别类去处理（自己处理会很麻烦的）
return mgesturedetector.ontouchevent(event);
}
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