android开发之滑动手势翻图 滑动手势监听

       今晚就再整理点有用的东西，这是关于手势滑动的例子：虽然网上也有，但是我还是整理了下，希望对读者有帮助：

下面贴出代码：

package android.apps;

import java.io.File;
import java.util.ArrayList;
import java.util.List;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.BaseAdapter;

import android.widget.GridView;

import android.widget.ImageView;

public class GridViewTest extends Activity {
	private File[] files;
	public static List pathsrcs;
	public static int ImagePositions;

	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.sdcard);
		GridView gridview = (GridView) findViewById(R.id.sdcard);
//		File f = android.os.Environment.getExternalStorageDirectory();
		files = new File("/sdcard/").listFiles();
		pathsrcs = new ArrayList();

		for (File file : files) {
			String path = file.getPath();
			// String path=file.getAbsolutePath();
			if (validate(path)) {
				pathsrcs.add(path);
			}

		}
		gridview.setAdapter(new ImageAdapter(this));
		gridview.setOnItemClickListener(new gridviewItemClick());
	}

	
	
	class gridviewItemClick implements OnItemClickListener {
		@Override
		public void onItemClick(AdapterView parent, View v, int position,
				long id) {
			//点击操作
			Intent intent = new Intent();
			ImagePositions=position;//图片的位置
			intent.setClass(GridViewTest.this, ShowImage.class);
			startActivity(intent);
		}

	}

	class ImageAdapter extends BaseAdapter {
		private Context mContext;

		public ImageAdapter(Context c) {
			mContext = c;
		}

		public int getCount() {
			return pathsrcs.size();
		}

		public Object getItem(int position) {
			return null;
		}

		public long getItemId(int position) {
			return 0;
			// return position;
		}

		public View getView(int position, View convertView, ViewGroup parent) {

			ImageView imageView;
			if (convertView == null) { // if it's not recycled, initialize some
										// attributes
				imageView = new ImageView(mContext);
				imageView.setLayoutParams(new GridView.LayoutParams(85, 85));//控制图片大小
				imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
				imageView.setPadding(8, 8, 8, 8);
			} else {
				imageView = (ImageView) convertView;
			}
			String path = pathsrcs.get(position);
			File file = new File(path);
			if (file.exists()) {
				Bitmap bitmap = BitmapFactory.decodeFile(path);
				imageView.setImageBitmap(bitmap);
			}
			return imageView;
		}
	}
	/**@判断是否存在该类型的图片
	 * @param fileName
	 * @return boolean
	 */
	private boolean validate(String fileName) {
		int idx = fileName.indexOf(".");
		String subfix = fileName.substring(idx + 1);
		if (fileName.equals("")) {
			return false;
		}
		// subfix.equals()||subfix.equals(".png")||subfix.equals(".jpeg")
		if ("jpg".equals(subfix)||"png".equals(subfix)||"gif".equals(subfix)) {
			return true;
		} else {
			return false;
		}
	}
}

手势类

package android.apps;

import android.app.Activity;
import android.net.Uri;
import android.os.Bundle;
import android.view.GestureDetector;
import android.view.GestureDetector.OnGestureListener;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.widget.ImageView;
import android.widget.Toast;

public class ShowImage extends Activity implements OnTouchListener,OnGestureListener{
	private static ImageView image = null;
	private static final int FLING_MIN_DISTANCE = 120;//移动最小距离
	private static final int FLING_MIN_VELOCITY = 200;//移动最大速度
	private int position;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
		image = (ImageView)findViewById(R.id.show);
		//pathsrcs-->存放图片路径的数组       ImagePositions-->选择的第几张图片
		String path = GridViewTest.pathsrcs.get(GridViewTest.ImagePositions);
		//设置图片显示路径
		image.setImageURI(Uri.parse(path));
		//设置Touch监听
		image.setOnTouchListener(this);
		//允许长按
		image.setLongClickable(true);
	}
	//构建手势探测器
	GestureDetector mygesture = new GestureDetector(this);
	@Override
	public boolean onTouch(View v, MotionEvent event) {
		return mygesture.onTouchEvent(event);
	}
	
	//显示下一张图片
	public void showNextImage(){
		position=++GridViewTest.ImagePositions;
		if(position>=GridViewTest.pathsrcs.size()){
			Toast.makeText(ShowImage.this, "已到最后一张图片", Toast.LENGTH_SHORT).show();
			GridViewTest.ImagePositions=GridViewTest.pathsrcs.size()-1;
		}else{
			String path = GridViewTest.pathsrcs.get(position);
			image.setImageURI(Uri.parse(path));
		}
		System.out.println("positoon="+position);
	}
	//显示上一张图片
	public void showLastImage(){
		position=--GridViewTest.ImagePositions;
		if(position<0){
			Toast.makeText(ShowImage.this, "已到第一张图片", Toast.LENGTH_SHORT).show();
			GridViewTest.ImagePositions=0;
		}else{
			String path = GridViewTest.pathsrcs.get(position);
			image.setImageURI(Uri.parse(path));
		}
	}
	/*用户按下触摸屏、快速移动后松开，由1个MotionEvent ACTION_DOWN, 
	 * 多个ACTION_MOVE, 1个ACTION_UP触发*/
	//主要方法
	@Override
	public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
			float velocityY) {
		// e1：第1个ACTION_DOWN MotionEvent 
		// e2：最后一个ACTION_MOVE MotionEvent 
		// velocityX：X轴上的移动速度（像素/秒） 
		// velocityY：Y轴上的移动速度（像素/秒） 
		
		// X轴的坐标位移大于FLING_MIN_DISTANCE，且移动速度大于FLING_MIN_VELOCITY个像素/秒 
		//向有翻图片
		if (e1.getX() - e2.getX() > FLING_MIN_DISTANCE    
		             && Math.abs(velocityX) > FLING_MIN_VELOCITY) {    
			showNextImage();
		     } 
		//向左翻图片
		if (e2.getX() - e1.getX() > FLING_MIN_DISTANCE    
		             && Math.abs(velocityX) > FLING_MIN_VELOCITY) {    
			showLastImage();
		}    
		   return false;    
	}
	//下面方法没用，但是这里必须实现
	/* 用户长按触摸屏，由多个MotionEvent ACTION_DOWN触发*/
	@Override
	public void onLongPress(MotionEvent e) {}
	
	/* 用户按下触摸屏，并拖动，由1个MotionEvent ACTION_DOWN, 多个ACTION_MOVE触发*/
	@Override
	public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX,float distanceY) {return false;}
	
	/* 用户轻触触摸屏，尚未松开或拖动，由一个1个MotionEvent ACTION_DOWN触发    
	  注意和onDown()的区别，强调的是没有松开或者拖动的状态    */
	@Override
	public void onShowPress(MotionEvent e) {}
	
	/*用户（轻触触摸屏后）松开，由一个1个MotionEvent ACTION_UP触发*/
	@Override
	public boolean onSingleTapUp(MotionEvent e) {return false;}
	
	@Override
	public boolean onDown(MotionEvent e) {return false;}
	
}

希望对读者有帮助