我们经常会在Android应用中看到左右滑动的效果,那么这种左右滑动效果是如何实现的呢?本文通过对Android代码的讲解,来分析Android中左右滑动效果的代码实现,希望对你有所帮助。
本示例演示在Android中实现图片左右滑动效果。
关于滑动效果,在Android中用得比较多,本示例实现的滑动效果是使用ViewFlipper来实现的,当然也可以使用其它的View来实现。接下来就让我们开始实现这种效果。为了方便大家理解,我们先来看一下效果图:
主要效果图如下图:
接下来我们看一下程序结构图:
MainActivity文件中代码:
- package com.android.flip;
- 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.animation.AnimationUtils;
- import android.widget.ImageView;
- import android.widget.ViewFlipper;
- /**
- * Android实现左右滑动效果
- * @Description: Android实现左右滑动效果
- * @File: MainActivity.java
- * @Package com.android.flip
- * @Author Hanyonglu
- * @Date 2012-02-12 上午10:44:04
- * @Version V1.0
- */
- public class MainActivity extends Activity implements OnGestureListener {
- private ViewFlipper flipper;
- private GestureDetector detector;
- /** Called when the activity is first created. */
- @Override
- public void onCreate(Bundle savedInstanceState) {
- super.onCreate(savedInstanceState);
- setContentView(R.layout.main);
- detector = new GestureDetector(this);
- flipper = (ViewFlipper) this.findViewById(R.id.ViewFlipper1);
- flipper.addView(addImageView(R.drawable.one));
- flipper.addView(addImageView(R.drawable.two));
- flipper.addView(addImageView(R.drawable.three));
- flipper.addView(addImageView(R.drawable.four));
- flipper.addView(addImageView(R.drawable.five));
- }
- private View addImageView(int id) {
- ImageView iv = new ImageView(this);
- iv.setImageResource(id);
- return iv;
- }
- @Override
- public boolean onTouchEvent(MotionEvent event) {
- // TODO Auto-generated method stub
- return this.detector.onTouchEvent(event);
- }
- @Override
- public boolean onDown(MotionEvent e) {
- // TODO Auto-generated method stub
- return false;
- }
- @Override
- public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
- float velocityY) {
- if (e1.getX() - e2.getX() > 120) {
- this.flipper.setInAnimation(AnimationUtils.loadAnimation(this, R.anim.push_left_in));
- this.flipper.setOutAnimation(AnimationUtils.loadAnimation(this, R.anim.push_left_out));
- this.flipper.showNext();
- return true;
- } else if (e1.getX() - e2.getX() < -120) {
- this.flipper.setInAnimation(AnimationUtils.loadAnimation(this, R.anim.push_right_in));
- this.flipper.setOutAnimation(AnimationUtils.loadAnimation(this, R.anim.push_right_out));
- this.flipper.showPrevious();
- return true;
- }
- return false;
- }
- @Override
- public void onLongPress(MotionEvent e) {
- // TODO Auto-generated method stub
- }
- @Override
- public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX,
- float distanceY) {
- // TODO Auto-generated method stub
- return false;
- }
- @Override
- public void onShowPress(MotionEvent e) {
- // TODO Auto-generated method stub
- }
- @Override
- public boolean onSingleTapUp(MotionEvent e) {
- // TODO Auto-generated method stub
- return false;
- }
- }
布局界面相对比较简单,我们只需要加入ViewFlipper就可以,代码如下:
- <?xml version="1.0" encoding="utf-8"?>
- <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
- android:orientation="vertical"
- android:layout_width="fill_parent"
- android:layout_height="fill_parent"
- >
- <ViewFlipper android:id="@+id/ViewFlipper1"
- android:layout_width="fill_parent"
- android:layout_height="fill_parent">
- </ViewFlipper>
- </LinearLayout>
为了使其滑动时有一定的特效,我们需要加入Animation效果,说到Animation,我们先看下如何在Android中实现自定义Animation。自定义的Animation是以XML格式定义的,定义好的XML文件存放在res/anim中。
一般的Animation有以下四种类型:
1. Alpha:渐变透明度动画效果
2. Scale:渐变尺寸伸缩动画效果
3. Translate:画面转换位置移动动画效果
4. Rotate:画面转换位置移动动画效果
push_left_in.xml文件中代码:
- <?xml version="1.0" encoding="utf-8"?>
- <set xmlns:android="http://schemas.android.com/apk/res/android">
- <translate android:fromXDelta="100%p" android:toXDelta="0"
- android:duration="500" />
- <alpha android:fromAlpha="0.1" android:toAlpha="1.0"
- android:duration="500" />
- </set>
push_left_out.xml文件中代码:
- <?xml version="1.0" encoding="utf-8"?>
- <set xmlns:android="http://schemas.android.com/apk/res/android">
- <translate android:fromXDelta="0" android:toXDelta="-100%p"
- android:duration="500" />
- <alpha android:fromAlpha="1.0" android:toAlpha="0.1"
- android:duration="500" />
- </set>
push_right_in.xml文件中代码:
- <?xml version="1.0" encoding="utf-8"?>
- <set xmlns:android="http://schemas.android.com/apk/res/android">
- <translate android:fromXDelta="-100%p" android:toXDelta="0"
- android:duration="500" />
- <alpha android:fromAlpha="0.1" android:toAlpha="1.0"
- android:duration="500" />
- </set>
push_right_out.xml文件中代码:
- <?xml version="1.0" encoding="utf-8"?>
- <set xmlns:android="http://schemas.android.com/apk/res/android">
- <translate android:fromXDelta="0" android:toXDelta="100%p"
- android:duration="500" />
- <alpha android:fromAlpha="1.0" android:toAlpha="0.1"
- android:duration="500" />
- </set>
来源: http://www.phpxs.com/code/1002278/