package com.example.eventtest;import java.util.ArrayList;import android.os.Bundle;import android.app.Activity;import android.gesture.GestureOverlayView;import android.gesture.GestureOverlayView.OnGestureListener;import android.graphics.Point;import android.view.Menu;import android.view.MotionEvent;import android.view.View;import android.view.View.OnClickListener;import android.widget.Toast;public class MainActivity extends Activity {		double nLenStart = 0;			@Override	protected void onCreate(Bundle savedInstanceState) {		super.onCreate(savedInstanceState);		setContentView(R.layout.activity_main);	}			@Override	public boolean onTouchEvent(MotionEvent event) {							int nCnt = event.getPointerCount();				int n = event.getAction();		if( (event.getAction()&MotionEvent.ACTION_MASK) == MotionEvent.ACTION_POINTER_DOWN && 2 == nCnt)//<span style="color:#ff0000;">2表示两个手指</span>		{								for(int i=0; i< nCnt; i++)			{				float x = event.getX(i);				float y = event.getY(i);								Point pt = new Point((int)x, (int)y);				}						int xlen = Math.abs((int)event.getX(0) - (int)event.getX(1));			int ylen = Math.abs((int)event.getY(0) - (int)event.getY(1));						nLenStart = Math.sqrt((double)xlen*xlen + (double)ylen * ylen);								}else if( (event.getAction()&MotionEvent.ACTION_MASK) == MotionEvent.ACTION_POINTER_UP  && 2 == nCnt)		{						for(int i=0; i< nCnt; i++)			{				float x = event.getX(i);				float y = event.getY(i);								Point pt = new Point((int)x, (int)y);			}						int xlen = Math.abs((int)event.getX(0) - (int)event.getX(1));			int ylen = Math.abs((int)event.getY(0) - (int)event.getY(1));						double nLenEnd = Math.sqrt((double)xlen*xlen + (double)ylen * ylen);						if(nLenEnd > nLenStart)//通过两个手指开始距离和结束距离，来判断放大缩小			{				Toast.makeText(getApplicationContext(), "放大", 3000).show();			}			else			{				Toast.makeText(getApplicationContext(), "缩小", 3000).show();			}		}							return super.onTouchEvent(event);	}}

基础知识：

getAction()方法返回的是int类型，用到的只有低16位，其中：低八位是动作的类型，高8位是触摸点索引值的表示（单点为0，双点为1）

获得动作类型： int action = event.getAction() &ACTION_MASK 或者使用 getActionMasked()

获得触摸点索引类型： int pointerIndex = (event.getAction() &ACTION_POINTER_INDEX_MASK ) >> ACTION_POINTER_INDEX_SHIFT

或者使用 getActionIndex()