Android 基于ImageSwitcher实现的左右切换图片

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

<?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

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http://blog.csdn.net/xiaanming/article/details/8997260，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

<?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

<?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

<?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

<?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>

好了，介绍完了，代码写的不是很好，写的不好的地方希望您指出，谢谢

代码下载