android——单点触控移动，多点触控放大缩小

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

    xmlns:tools="http://schemas.android.com/tools"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    tools:context=".MainActivity" >

    <ImageView

        android:id="@+id/imgage"

        android:src="@drawable/test"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:layout_centerHorizontal="true"

        android:layout_centerVertical="true"

       />

</RelativeLayout>

package com.example.touchdemo;

import android.os.Bundle;

import android.app.Activity;

import android.content.res.Resources;

import android.util.DisplayMetrics;

import android.util.Log;

import android.view.Menu;

import android.view.MotionEvent;

import android.view.View;

import android.view.View.OnTouchListener;

import android.widget.ImageView;

import android.widget.RelativeLayout;

import android.widget.Toast;

public class MainActivity extends Activity {

    private ImageView image;

    float lastDistance = -1;

    float x0 = 0;

    float y0 = 0;

     private int screenWidth;

       private int screenHeight; 

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        image = (ImageView) findViewById(R.id.imgage);

        //获得屏幕宽高 不让出界

         DisplayMetrics dm = getResources().getDisplayMetrics();

            screenWidth = dm.widthPixels;

            screenHeight = dm.heightPixels-100; 

        image.setOnTouchListener(new OnTouchListener() {

            private float x;

            private float y;

            @Override

            public boolean onTouch(View v,final MotionEvent event) {

                // TODO Auto-generated method stub

                int action = event.getAction();

                Log.i("TAG","触摸开始......");

                switch (action) {

                case MotionEvent.ACTION_DOWN:

                    //getX()是表示Widget相对于自身左上角的x坐标,而getRawX()是表示相对于屏幕左上角的x坐标值(注意:这个屏幕左上角是手机屏幕左上角,不管activity是否有titleBar或是否全屏幕)

                    x = event.getRawX();

                    y = event.getRawX();

                    break;

                case MotionEvent.ACTION_MOVE:

                    //得到触摸点的个数

                    int count = event.getPointerCount();

                    Log.i("TAG","触摸点的个数："+count);

                    if(count > 1){

                        Log.i("TAG", event.getX(0)+","+event.getY(0)+"|"+event.getX(1)+","+event.getY(1));

                        //获得两点的坐标差

                        float distanceX = event.getX(0) - event.getX(1);

                        float distanceY = event.getY(0) - event.getY(1);

                        //获得两点之间的距离

                        float betweenDistance = (float) Math.sqrt(distanceX*distanceX + distanceY*distanceY);

                        Log.i("TAG","当前两点之间的新距离："+betweenDistance);

                        if(betweenDistance < 1){

                            lastDistance = betweenDistance;

                        }else if((betweenDistance - lastDistance) > 5){

                            //放大

                            lastDistance = betweenDistance;

                            //获得布局参数

                            RelativeLayout.LayoutParams params = (android.widget.RelativeLayout.LayoutParams) image.getLayoutParams();

                            params.width = (int) (image.getWidth()*1.1f);

                            params.height = (int) (image.getHeight()*1.1f);

                            image.setLayoutParams(params);

                        }else if((lastDistance - betweenDistance) > 5){

                            lastDistance = betweenDistance;

                            //获得布局参数

                            RelativeLayout.LayoutParams params = (android.widget.RelativeLayout.LayoutParams) image.getLayoutParams();

                            params.width = (int) (image.getWidth()*0.9f);

                            params.height = (int) (image.getHeight()*0.9f);

                            image.setLayoutParams(params);

                        }

                    }else if(count == 1){

                        //移动距离

                        float rawX = event.getRawX()-x;

                        float rawy = event.getRawY()-y;

                        //定义新的

                        int left = (int) (image.getLeft()+rawX);

                        int top = (int) (image.getTop()+rawy);

                        int right = (int) (image.getRight()+rawX);

                        int bottom = (int) (image.getBottom()+rawy);

                         // 设置不能出界

                          if (left < 0) {

                              left = 0;

                              right = left + v.getWidth();

                          } 

                          if (right > screenWidth) {

                              right = screenWidth;

                              left = right - v.getWidth();

                          } 

                          if (top < 0) {

                              top = 0;

                              bottom = top + v.getHeight();

                          } 

                          if (bottom > screenHeight) {

                              bottom = screenHeight;

                              top = bottom - v.getHeight();

                          } 

                        //赋值

                        image.layout(left, top, right, bottom);

                        //改成新的按下作标

                        x=event.getRawX();

                        y=event.getRawY();

                        /*return false;*/

                    }

                    break;

                }

                return true;

            }

        });

    }

    //全局移动

   @Override

public boolean onTouchEvent(MotionEvent event) {

    // TODO Auto-generated method stub

      /*image.setX(event.getX());

        image.setY(event.getY()); */

    return true;

}

}