android viewflipper的使用 实现图片滑动效果

package com.homer.viewflipper;

import android.app.Activity;
import android.os.Bundle;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.view.ViewGroup.LayoutParams;
import android.view.animation.Animation;
import android.view.animation.AnimationUtils;
import android.widget.ImageView;
import android.widget.ViewFlipper;

public class ViewFlipperActivity extends Activity implements android.view.GestureDetector.OnGestureListener {
	private int[] imgs = { R.drawable.img1, R.drawable.img2,
					  R.drawable.img3, R.drawable.img4, R.drawable.img5 };

	private GestureDetector gestureDetector = null;
	private ViewFlipper viewFlipper = null;

	private Activity mActivity = null;

	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);

		mActivity = this;

		viewFlipper = (ViewFlipper) findViewById(R.id.viewflipper);
		gestureDetector = new GestureDetector(this);	// 声明检测手势事件

		for (int i = 0; i < imgs.length; i++) { 			// 添加图片源
			ImageView iv = new ImageView(this);
			iv.setImageResource(imgs[i]);
			iv.setScaleType(ImageView.ScaleType.FIT_XY);
			viewFlipper.addView(iv, new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT));
		}
		
		viewFlipper.setAutoStart(true);			// 设置自动播放功能（点击事件，前自动播放）
		viewFlipper.setFlipInterval(3000);
		if(viewFlipper.isAutoStart() && !viewFlipper.isFlipping()){
			viewFlipper.startFlipping();
		}
	}

	@Override
	public boolean onTouchEvent(MotionEvent event) {
		viewFlipper.stopFlipping();				// 点击事件后，停止自动播放
		viewFlipper.setAutoStart(false);	
		return gestureDetector.onTouchEvent(event); 		// 注册手势事件
	}

	@Override
	public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
		if (e2.getX() - e1.getX() > 120) {			 // 从左向右滑动（左进右出）
			Animation rInAnim = AnimationUtils.loadAnimation(mActivity, R.anim.push_right_in); 	// 向右滑动左侧进入的渐变效果（alpha  0.1 -> 1.0）
			Animation rOutAnim = AnimationUtils.loadAnimation(mActivity, R.anim.push_right_out); // 向右滑动右侧滑出的渐变效果（alpha 1.0  -> 0.1）

			viewFlipper.setInAnimation(rInAnim);
			viewFlipper.setOutAnimation(rOutAnim);
			viewFlipper.showPrevious();
			return true;
		} else if (e2.getX() - e1.getX() < -120) {		 // 从右向左滑动（右进左出）
			Animation lInAnim = AnimationUtils.loadAnimation(mActivity, R.anim.push_left_in);		// 向左滑动左侧进入的渐变效果（alpha 0.1  -> 1.0）
			Animation lOutAnim = AnimationUtils.loadAnimation(mActivity, R.anim.push_left_out); 	// 向左滑动右侧滑出的渐变效果（alpha 1.0  -> 0.1）

			viewFlipper.setInAnimation(lInAnim);
			viewFlipper.setOutAnimation(lOutAnim);
			viewFlipper.showNext();
			return true;
		}
		return true;
	}

	@Override
	public boolean onDown(MotionEvent e) {
		return false;
	}

	@Override
	public void onLongPress(MotionEvent e) {
	}

	@Override
	public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
		return false;
	}

	@Override
	public void onShowPress(MotionEvent e) {
	}

	@Override
	public boolean onSingleTapUp(MotionEvent e) {
		return false;
	}
}