android手势简单认识...

在Android系统中，每一次手势交互都会依照以下顺序执行。

　　1. 接触接触屏一刹那，触发一个MotionEvent事件。

　　2. 该事件被OnTouchListener监听，在其onTouch()方法里获得该MotionEvent对象。

　　3. 通过GestureDetector（手势识别器）转发次MotionEvent对象至OnGestureListener。

　　4. OnGestureListener获得该对象，听根据该对象封装的的信息，做出合适的反馈。

　　这个顺序可以说就是手势交互的原理，下面一同来了解一下MotionEvent、GestureDetector和OnGestureListener。

　　MotionEvent: 这个类用于封装手势、触摸笔、轨迹球等等的动作事件。其内部封装了两个重要的属性X和Y，这两个属性分别用于记录横轴和纵轴的坐标。

　　GestureDetector: 识别各种手势。

　　OnGestureListener: 这是一个手势交互的监听接口，其中提供了多个抽象方法，并根据GestureDetector的手势识别结果调用相对应的方法。

参考代码如下

package hfut.gmm;

import java.util.ArrayList;

import android.app.Activity;
import android.gesture.Gesture;
import android.gesture.GestureLibraries;
import android.gesture.GestureLibrary;
import android.gesture.GestureOverlayView;
import android.gesture.Prediction;
import android.gesture.GestureOverlayView.OnGesturePerformedListener;
import android.os.Bundle;
import android.util.Log;
import android.view.ContextMenu;
import android.view.GestureDetector;
import android.view.Menu;
import android.view.MenuItem;
import android.view.MotionEvent;
import android.view.View;
import android.view.Window;
import android.view.ContextMenu.ContextMenuInfo;
import android.view.GestureDetector.OnGestureListener;
import android.view.View.OnTouchListener;
import android.view.ViewGroup.LayoutParams;
import android.view.animation.AnimationUtils;
import android.widget.ImageSwitcher;
import android.widget.ImageView;
import android.widget.Toast;
import android.widget.ViewSwitcher.ViewFactory;

public class MainActivity extends Activity implements ViewFactory, OnTouchListener, OnGestureListener {
    /** Called when the activity is first created. */
    private ImageSwitcher imgswitcher;
    private Integer[] pics = { R.drawable.pic_one, R.drawable.pic_two,
			R.drawable.pic_three, R.drawable.pic_four, R.drawable.pic_five,R.drawable.pic_six,
			R.drawable.pic_seven
			};
    int index;
    private boolean success;  
    private GestureDetector detector ;
    GestureLibrary library;
	@Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        this.requestWindowFeature(Window.FEATURE_NO_TITLE);
        setContentView(R.layout.main);
        detector=new GestureDetector(this); 
        imgswitcher=(ImageSwitcher)this.findViewById(R.id.imageSwitcher1);
        imgswitcher.setFactory(this);
		imgswitcher.setInAnimation(AnimationUtils.loadAnimation(this,
			    android.R.anim.fade_in));
		imgswitcher.setOutAnimation(AnimationUtils.loadAnimation(this,
			    android.R.anim.fade_out));
		
		imgswitcher.setImageResource(pics[2]);
	     imgswitcher.setOnTouchListener(this);
		imgswitcher.setLongClickable(true);
		detector.setIsLongpressEnabled(true);//Set whether longpress is enabled
		
		this.registerForContextMenu(this.findViewById(R.id.textView1));
		
		
		library = GestureLibraries.fromRawResource(this, R.raw.gestures);  
		//加载手势库  
        success = library.load(); 
		//找到手势识别控件
		GestureOverlayView gestureView = (GestureOverlayView)this.findViewById(R.id.gestures);
		
		gestureView.addOnGesturePerformedListener(new GestureListener());  
		
        
    }
	//手势识别监听...
	class GestureListener implements OnGesturePerformedListener  {

		@Override
		public void onGesturePerformed(GestureOverlayView arg0, Gesture gesture) {
			// TODO Auto-generated method stub
			if(success)  
            {  
                //从手势库中查找匹配的手势,最匹配的记录会放在最前面  
                ArrayList<Prediction> predictions = library.recognize(gesture);  
                if(!predictions.isEmpty())  
                {  
                    Prediction prediction = predictions.get(0);  
                    //Log中显示出匹配程度  
                    Log.i("Infor", "score:"+ prediction.score);  
                    //匹配程度大于30%  
                    if(prediction.score>3)  
                    {  
                        //这是关闭的手势  
                        if("question".equals(prediction.name))  
                        {  
                            Toast.makeText(MainActivity.this, "当前手势：question", Toast.LENGTH_LONG).show();  
                        }  
                    }
		}
            }
		
	}
	}
	public void nextgirl(){
		index++;
		imgswitcher.setImageResource(pics[index%pics.length]);
	}
	public void pregirl(){
		index--;
		if(index==-1)
			index=pics.length-1;
		
		imgswitcher.setImageResource(pics[index%pics.length]);
	}
	@Override
	public View makeView() {
		// TODO Auto-generated method stub
		ImageView i = new ImageView(this);
		  i.setBackgroundColor(0xFF011000);
		  i.setScaleType(ImageView.ScaleType.FIT_XY);
		  i.setLayoutParams(new ImageSwitcher.LayoutParams(
		    LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT));
		  return i;
	}
	@Override
	public boolean onTouch(View arg0, MotionEvent arg1) {
		// TODO Auto-generated method stub
		detector.onTouchEvent(arg1);  //将motionEvent事件添加进GestureDetector进行监听处理
		return true;
	}
	@Override
	public boolean onDown(MotionEvent arg0) {
		// TODO Auto-generated method stub
		Log.d("Infor", "onDown被调用...");
		return false;
	}
	@Override
	public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
			float velocityY) {
		// TODO Auto-generated method stub
		if(velocityX<0)
		nextgirl();
		else if(velocityX>0)
		pregirl();
		
		Log.d("Infor", "onFling被用调用");
		return false;
	}
	@Override
	public void onLongPress(MotionEvent arg0) {
		// TODO Auto-generated method stub
		Log.d("Infor", "长按");
		
	}
	@Override
	public boolean onScroll(MotionEvent arg0, MotionEvent arg1, float arg2,
			float arg3) {
		// TODO Auto-generated method stub
		Log.d("Infor", "onScroll被用调用");
		return false;
	}
	@Override
	public void onShowPress(MotionEvent arg0) {
		// TODO Auto-generated method stub
		Log.d("Infor", "onShowPress被用调用");
	}
	@Override
	public boolean onSingleTapUp(MotionEvent arg0) {
		// TODO Auto-generated method stub
		Log.d("Infor", "onSingleTapUp被用调用");
		return false;
	}
	
	
	
	
	
	
	
	//上下文菜单....

	public boolean onContextItemSelected(MenuItem item) {
		// TODO Auto-generated method stub
		return super.onContextItemSelected(item);
	}
	@Override
	public void onCreateContextMenu(ContextMenu menu, View v,
			ContextMenuInfo menuInfo) {
		// TODO Auto-generated method stub
		super.onCreateContextMenu(menu, v, menuInfo);
		 menu.add(0,Menu.FIRST, 0, "菜单");
	}
	
}

xml文件：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:weightSum="1">
    <TextView android:text="TextView" android:layout_height="wrap_content" android:id="@+id/textView1" android:layout_width="match_parent"></TextView>

<ImageSwitcher android:layout_width="match_parent" android:id="@+id/imageSwitcher1" android:layout_height="wrap_content" android:layout_weight="0.61"></ImageSwitcher>

<!--添加手势识别的控件  -->  
    <android.gesture.GestureOverlayView  
        android:layout_width="fill_parent"   
        android:layout_height="0dip"  
        android:gestureStrokeType="multiple"  
        android:id="@+id/gestures"  
        android:layout_weight="1.24"/>  
</LinearLayout>

上述代码主要实现两个功能：

1、手势交互功能

通过一个imageSwitcher对它进行左右滑动切换图片从而可以实现类似翻页功能....

2、手势识别功能（红体字标识）

通过使用Android SDK samples里面自带的GestureBuilder建立手势库（位置：android-sdk-windows/samples/android-8/GestureBuilder），运行就可以使用GestureBuilder建立手势库，生成的手势库文件在SCDard根目录下，默认文件名称为：gestures

把手势库文件gestures文件拷贝到项目的res/raw目录下。然后在布局文件中添加用于手势绘制的View：

PS：由于布局存在些许BUG，可能调试的时候无法两个功能同时显示，所以可以一个功能一个功能的调试.实现demo

参考博文：http://blog.csdn.net/kesenhoo/article/details/6550849

                   http://www.cnblogs.com/wisekingokok/archive/2011/08/30/2158358.html