imageSwitch（图片轮播）使用代码详解

package liu;

import com.example.demo_0330.R;
import android.app.Activity;
import android.os.Bundle;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.widget.ImageSwitcher;
import android.widget.ImageView;
import android.widget.ViewSwitcher.ViewFactory;

public class ImageSwitcher_Activity extends Activity implements ViewFactory,
		OnTouchListener {
	private ImageSwitcher imageswitcher;
	private int index;
	private int[] images = { R.drawable.mingren, R.drawable.xiaoying,
			R.drawable.zuozhu, R.drawable.xuanfuqiu };

	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.imageswitcher_activity);
		imageswitcher = (ImageSwitcher) findViewById(R.id.imageswitcher);
		imageswitcher.setFactory(this);
		imageswitcher.setOnTouchListener(this);
	}

	// 适配器
	public View makeView() {
		ImageView im = new ImageView(this);
		im.setImageResource(images[0]);
		return im;
	}
	
	float startX=0.0f;
	float netX=0.0f;
	
	// 滑屏事件
	public boolean onTouch(View v, MotionEvent event) {
		
		int action=event.getAction();//获取当前事件
			//action==MotionEvent.ACTION_DOWN   表示触碰获得焦点
		if (action==MotionEvent.ACTION_DOWN) {
			startX=event.getX();
			return true;
		}
		
		if (action==MotionEvent.ACTION_UP) {
			netX=event.getX();
			if (startX-netX>20) {
				index=index+1<images.length?++index:0;
				//动画效果
				imageswitcher.setInAnimation(this, android.R.anim.fade_in);
				imageswitcher.setOutAnimation(this, android.R.anim.fade_out);
			}else if(netX-startX>20){
				index=index-1>=0?--index:images.length-1;
				//动画效果
				imageswitcher.setInAnimation(this, android.R.anim.fade_in);
				imageswitcher.setOutAnimation(this, android.R.anim.fade_out);
			}
			imageswitcher.setImageResource(images[index]);
		}
		
		return false;
	}

}