Android基于ImageSwitcher实现左右切换图片

原文地址：http://blog.csdn.net/xiaanming/article/details/8988152

左右切换图片控件大家都用ViewPager, ViewFipper比较多吧，我之前也用ViewPager实现了，使用ViewPager实现左右循环滑动图片，有兴趣的可以去看下，今天介绍的是基于ImageSwitcher实现的左右切换图片，先上截图吧





好了，接下来来看代码吧，第一张图是一个GridView，点击item跳转到第二个界面，第一个界面可以忽略，主要是讲解ImageSwitcher的左右却换图片，先看布局文件

[html] view
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<?xml version="1.0" encoding="UTF-8"?>

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"

android:layout_width="fill_parent"

android:layout_height="fill_parent" >

<ImageSwitcher

android:id="@+id/imageSwitcher1"

android:layout_width="fill_parent"

android:layout_height="fill_parent">

</ImageSwitcher>

<RelativeLayout

android:layout_width="fill_parent"

android:layout_height="wrap_content"

android:orientation="vertical" >

<LinearLayout

android:id="@+id/viewGroup"

android:layout_width="fill_parent"

android:layout_height="wrap_content"

android:layout_alignParentBottom="true"

android:layout_marginBottom="30dp"

android:gravity="center_horizontal"

android:orientation="horizontal" >

</LinearLayout>

</RelativeLayout>

</FrameLayout>

然后就是Activity代码啦，总体来说比较简单，代码我添加了注释

[java] view
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package com.example.photoalbum;

import android.app.Activity;

import android.os.Bundle;

import android.view.MotionEvent;

import android.view.View;

import android.view.View.OnTouchListener;

import android.view.ViewGroup;

import android.view.animation.AnimationUtils;

import android.widget.ImageSwitcher;

import android.widget.ImageView;

import android.widget.LinearLayout;

import android.widget.RelativeLayout.LayoutParams;

import android.widget.Toast;

import android.widget.ViewSwitcher.ViewFactory;

public class ShowPhotoActivity extends Activity implements ViewFactory, OnTouchListener{

/**

* ImagaSwitcher 的引用

*/

private ImageSwitcher mImageSwitcher;

/**

* 图片id数组

*/

private int[] imgIds;

/**

* 当前选中的图片id序号

*/

private int currentPosition;

/**

* 按下点的X坐标

*/

private float downX;

/**

* 装载点点的容器

*/

private LinearLayout linearLayout;

/**

* 点点数组

*/

private ImageView[] tips;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.show_photo);

imgIds = new int[]{R.drawable.item01,R.drawable.item02,R.drawable.item03,R.drawable.item04,

R.drawable.item05, R.drawable.item06, R.drawable.item07, R.drawable.item08,R.drawable.item09,

R.drawable.item10, R.drawable.item11, R.drawable.item12};

//实例化ImageSwitcher

mImageSwitcher = (ImageSwitcher) findViewById(R.id.imageSwitcher1);

//设置Factory

mImageSwitcher.setFactory(this);

//设置OnTouchListener，我们通过Touch事件来切换图片

mImageSwitcher.setOnTouchListener(this);

linearLayout = (LinearLayout) findViewById(R.id.viewGroup);

tips = new ImageView[imgIds.length];

for(int i=0; i<imgIds.length; i++){

ImageView mImageView = new ImageView(this);

tips[i] = mImageView;

LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(new ViewGroup.LayoutParams(LayoutParams.WRAP_CONTENT,

LayoutParams.WRAP_CONTENT));

layoutParams.rightMargin = 3;

layoutParams.leftMargin = 3;

mImageView.setBackgroundResource(R.drawable.page_indicator_unfocused);

linearLayout.addView(mImageView, layoutParams);

}

//这个我是从上一个界面传过来的，上一个界面是一个GridView

currentPosition = getIntent().getIntExtra("position", 0);

mImageSwitcher.setImageResource(imgIds[currentPosition]);

setImageBackground(currentPosition);

}

/**

* 设置选中的tip的背景

* @param selectItems

*/

private void setImageBackground(int selectItems){

for(int i=0; i<tips.length; i++){

if(i == selectItems){

tips[i].setBackgroundResource(R.drawable.page_indicator_focused);

}else{

tips[i].setBackgroundResource(R.drawable.page_indicator_unfocused);

}

}

}

@Override

public View makeView() {

final ImageView i = new ImageView(this);

i.setBackgroundColor(0xff000000);

i.setScaleType(ImageView.ScaleType.CENTER_CROP);

i.setLayoutParams(new ImageSwitcher.LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT));

return i ;

}

@Override

public boolean onTouch(View v, MotionEvent event) {

switch (event.getAction()) {

case MotionEvent.ACTION_DOWN:{

//手指按下的X坐标

downX = event.getX();

break;

}

case MotionEvent.ACTION_UP:{

float lastX = event.getX();

//抬起的时候的X坐标大于按下的时候就显示上一张图片

if(lastX > downX){

if(currentPosition > 0){

//设置动画，这里的动画比较简单，不明白的去网上看看相关内容

mImageSwitcher.setInAnimation(AnimationUtils.loadAnimation(getApplication(), R.anim.left_in));

mImageSwitcher.setOutAnimation(AnimationUtils.loadAnimation(getApplication(), R.anim.right_out));

currentPosition --;

mImageSwitcher.setImageResource(imgIds[currentPosition % imgIds.length]);

setImageBackground(currentPosition);

}else{

Toast.makeText(getApplication(), "已经是第一张", Toast.LENGTH_SHORT).show();

}

}

if(lastX < downX){

if(currentPosition < imgIds.length - 1){

mImageSwitcher.setInAnimation(AnimationUtils.loadAnimation(getApplication(), R.anim.right_in));

mImageSwitcher.setOutAnimation(AnimationUtils.loadAnimation(getApplication(), R.anim.lift_out));

currentPosition ++ ;

mImageSwitcher.setImageResource(imgIds[currentPosition]);

setImageBackground(currentPosition);

}else{

Toast.makeText(getApplication(), "到了最后一张", Toast.LENGTH_SHORT).show();

}

}

}

break;

}

return true;

}

}

上面切换图片主要用到的就是动画了，用的是translate移动动画，不了解动画的同学到这里看看/article/1332711.html，我就不介绍了，接下来我吧动画代码贴出来，在res新建一个anim的目录，如下图



左边进入的动画，left_in.xml

[html] view
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<?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"/>

</set>

左边出去的动画,left_out.xml

[html] view
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<?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"/>

</set>

右边进入的动画，right_in.xml

[html] view
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<?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"/>

</set>

右边出去的动画,right_out.xml

[html] view
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<?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"/>

</set>