Android之ImageSwitcher

ImageSwitcher，把她理解成一个相框的话，里面放的是一张张相片(ImageView对象)，事实上，ImageSwitcher本身也是集成FrameLayout。

OK，直接上代码。

public class ImageSwitcherActivity extends Activity implements ViewFactory,OnClickListener{
    /** Called when the activity is first created. */
	private static final int BUTTON_DWON_ID=0x123456;
	 private static final int BUTTON_UP_ID=0x123457;
	 private static final int SWITCHER_ID=0x123458;
	 private int index=0;
	 private ImageSwitcher switcher;
	 int []images=new int[]{R.drawable.f,R.drawable.t,R.drawable.y};
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        //setContentView(R.layout.main);
      
      switcher  =new ImageSwitcher(this);
      //创建一个布局
      LinearLayout layout=new LinearLayout(this);
      setContentView(layout);
      //加入组件
      layout.addView(switcher);
      switcher.setFactory(this);//设置工厂
      switcher.setImageResource(images[index]);
      //设置动画效果
      switcher.setInAnimation(AnimationUtils.loadAnimation(this	, android.R.anim.fade_in)) ;
      switcher.setOutAnimation(AnimationUtils.loadAnimation(this, android.R.anim.fade_out));
     
      LinearLayout.LayoutParams params=new LinearLayout.LayoutParams(100,100);
      
      //创建下一张按钮
      Button nextBt=new Button(this);
      nextBt.setText("下一张");
      nextBt.setId(BUTTON_DWON_ID);
      nextBt.setOnClickListener(this);//创建监听
      layout.addView(nextBt, params);
      
      //创建上一张按钮
      Button preBt=new Button(this);
      preBt.setText("上一张");
      preBt.setId(BUTTON_UP_ID);
      preBt.setOnClickListener(this);//创建监听 
      layout.addView(preBt, params);
    }
	@Override
	public View makeView() {
		// TODO Auto-generated method stub
		ImageView imageView =new ImageView(this);
		imageView.setBackgroundColor(0xFF000000);
		imageView.setScaleType(ImageView.ScaleType.FIT_CENTER);
		imageView.setLayoutParams(new ImageSwitcher.LayoutParams(LayoutParams.MATCH_PARENT,
				                 LayoutParams.MATCH_PARENT));
		return imageView;
	}
	@Override
	public void onClick(View v) {
		// TODO Auto-generated method stub
	switch (v.getId()) {
	case BUTTON_DWON_ID:
		index++;
		if(index>=images.length){
			index=0;
		}
		switcher.setImageResource(images[index]);
		break;
	case BUTTON_UP_ID:
		index--;
		if(index<0){
			index=images.length-1;
		}
		switcher.setImageResource(images[index]);
		break;	
	default:
		break;
	}	
		
		
	}
}

简单解释下上述代码

要想让ImageSwitcher装载ImageView,就必须通过setFactory这个方法，并且重写ViewFactory的makeView方法