ImageSwitcher图片切换控件

   ImageSwitcher控件可以用在不同的图像之间切换，其中切换的过程可以采用动画的方法，如淡入淡出的效果。

   ImageSwitcher需要一个图像工厂（ViewFactory）来创建用于显示图像的ImageView对象，因此我们需要一个实现android:widget.ViewSwitcher.ViewFactory接口的类。

一、建立工程，如图

二、activity_main.xml中代码

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    >

    <ImageSwitcher
        android:id="@+id/imageSwitcher1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:layout_marginLeft="60dp"
        android:layout_marginTop="60dp" >
    </ImageSwitcher>

    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_centerVertical="true"
        android:layout_below="@+id/imageSwitcher1"
        android:layout_marginLeft="45dp"
        android:text="next" />

    <Button
        android:id="@+id/button2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignBaseline="@+id/button1"
        android:layout_alignBottom="@+id/button1"
        android:layout_toRightOf="@+id/button1"
        android:layout_below="@+id/imageSwitcher1"
        android:text="forward" />

</RelativeLayout>

三、MainActivity.java中代码

package com.study.imageswitcher;

import java.util.ArrayList;
import java.util.List;

import android.os.Bundle;
import android.app.Activity;
import android.graphics.drawable.Drawable;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageSwitcher;
import android.widget.ImageView;
import android.widget.ViewSwitcher.ViewFactory;

public class MainActivity extends Activity implements OnClickListener,ViewFactory{

    private ImageSwitcher imageSwitcher;
    private Button button1,button2;
    private int index = 0;//用于浏览图片的次序
    private List<Drawable> list = new ArrayList<Drawable>();
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        imageSwitcher = (ImageSwitcher) this.findViewById(R.id.imageSwitcher1);
        button1 = (Button)this.findViewById(R.id.button1);
        button2 = (Button)this.findViewById(R.id.button2);
        button1.setOnClickListener(this);
        button2.setOnClickListener(this);
        imageSwitcher.setFactory(this);
        //往list集合里装载图片信息
        list.add(getResources().getDrawable(R.drawable.item1));
        list.add(getResources().getDrawable(R.drawable.item2));
        list.add(getResources().getDrawable(R.drawable.item3));
        list.add(getResources().getDrawable(R.drawable.item4));
        list.add(getResources().getDrawable(R.drawable.item5));
        list.add(getResources().getDrawable(R.drawable.item6));
        list.add(getResources().getDrawable(R.drawable.item7));
        list.add(getResources().getDrawable(R.drawable.item8));
        //初始化加载图片的信息
        if(list.size() > 0){
            imageSwitcher.setImageDrawable(list.get(0));
        }
    }


    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }


    @Override
    public void onClick(View v) {
        switch (v.getId()) {
        case R.id.button1:
            index--;
            if(index < 0){
                index = list.size() - 1;
            }
            imageSwitcher.setImageDrawable(list.get(index));
            break;
        case R.id.button2:
            index++;
            if(index >= list.size()){
                index = 0;
            }
            imageSwitcher.setImageDrawable(list.get(index));

        default:
            break;
        }
        
    }


    @Override
    public View makeView() {
        // TODO Auto-generated method stub
        return new ImageView(MainActivity.this);
    }
    
}

四、效果图