Android ImageSwitcher

ImageSwitcher 继承自ViewSwitcher。ImageSwitcher继承自ViewSwitcher,并重写了showNext,showPrevious方法，ViewFactory返回的组件必须是ImageView,使用更简单。只需要两步：

1. 为ImageSwitcher提供一个ViewFactory，ViewFactory返回的只能是ImageView

2. 切换图片时只需要调用ImageSwitcher的

public void setImageDrawable(Drawable drawable) 
public void setImageResource(int resid) 
public void setImageURI(Uri uri)      

// -----------ImageSwitcher--------------

    final ImageSwitcher imageSwitcher = (ImageSwitcher) findViewById(R.id.imageSwitcher);
    Button IButton1 = (Button) findViewById(R.id.IButton1);
    Button IButton2 = (Button) findViewById(R.id.IButton2);

    final int currentPig[] = { -1 };// 数据源设为上面的那个数组。
    // int[] images = {};

    imageSwitcher.setInAnimation(ViewAnimatorDemo.this,
        android.R.anim.fade_in);
    imageSwitcher.setOutAnimation(ViewAnimatorDemo.this,
        android.R.anim.fade_out);

    imageSwitcher.setFactory(new ViewFactory() {

      @Override
      public View makeView() {
        // TODO Auto-generated method stub

        ImageView image = new ImageView(ViewAnimatorDemo.this);
        image.setScaleType(ImageView.ScaleType.FIT_CENTER);
        image.setLayoutParams(new ImageSwitcher.LayoutParams(
            LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));

        return image;
      }
    });

    OnClickListener IListener = new OnClickListener() {

      @Override
      public void onClick(View v) {
        // TODO Auto-generated method stub
        if (v.getId() == R.id.IButton1) {
          if (--currentPig[0] < 0)
            currentPig[0] = images.length - 1;
        } else {
          if (++currentPig[0] >= images.length)
            currentPig[0] = 0;
        }
        imageSwitcher.setImageResource(images[currentPig[0]]);
      }
    };

    IButton1.setOnClickListener(IListener);
    IButton2.setOnClickListener(IListener);
    // 初始化一下
    currentPig[0] = 0;
    imageSwitcher.setImageResource(images[currentPig[0]]);