触摸事件,可以包含多点触摸,也可以使用捏合手势缩放,并且放大图片;

多点触摸的实现:

num =motionEvent.getPointerCount()//使用MotionEvent的此方法来获取当前手指的数量.

然后使用一个循环,进行手指数据的遍历:

id = 0;

while(id < num){

int ptridx = motionEvent.getPointerId(id);

float x1 = motionEvent.getX(ptridx);

float y1 = motionEvent.getY(ptridx);

Log.d(TAG,"x1="+x1+",y1="+y1);//手指的屏幕坐标

float pressure = motionEvent.getPressure(ptridx);//压力

float size = motionEvent.getSize(ptridx);//手指尺寸

id++;//下一根手指

}

其余的全部代码:

package com.lanxin.testtouch;

import android.graphics.Matrix;

import android.support.v7.app.AppCompatActivity;

import android.os.Bundle;

import android.util.Log;

import android.view.MotionEvent;

import android.view.ScaleGestureDetector;

import android.view.View;

import android.widget.ImageView;

import android.widget.TextView;

public class MainActivity extends AppCompatActivity implements View.OnTouchListener {

private static final String TAG = "TouchLog";

float y = 0;

float x = 0;

ImageView img;

ScaleGestureDetector mScaleGesture;

float mScaleFloat = 1f;

Matrix matrix = new Matrix();

TextView text2;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

//RelativeLayout relativeLayout = (RelativeLayout)findViewById(R.id.relativeLayout);//使用relativeLayout来绑定触摸事件

//relativeLayout.setOnTouchListener(this);//添加事件监听

//捏合手势的演示

text2 = (TextView)findViewById(R.id.text2);

img = (ImageView)findViewById(R.id.images1);

mScaleGesture = new ScaleGestureDetector(this, new ScaleGestureDetector.OnScaleGestureListener() {

@Override

public boolean onScale(ScaleGestureDetector detector) {

mScaleFloat *= detector.getScaleFactor();

String str = "";

str = "比例:"+detector.getScaleFactor()+" mScaleFloat:"+mScaleFloat+"\n";

mScaleFloat = Math.max(0.1f,Math.min(mScaleFloat,5.0f));//图像比例,最小0.1,最大5

str += " mScaleFloat:"+mScaleFloat;

text2.setText(str);

matrix.setScale(mScaleFloat, mScaleFloat);

img.setImageMatrix(matrix);

img.invalidate();

return true;//这里一定要返回真,否则不会继续监听事件

}

@Override

public boolean onScaleBegin(ScaleGestureDetector scaleGestureDetector) {

return true;//这里一定要返回真,否则不会继续监听事件

}

@Override

public void onScaleEnd(ScaleGestureDetector scaleGestureDetector) {

}

});

//捏合手势演示结束

}

public boolean onTouchEvent(MotionEvent event){

mScaleGesture.onTouchEvent(event);//为捏合手势绑定触摸事件

Log.d(TAG,"onTouchEvent");

return true;

}

@Override

public boolean onTouch(View view, MotionEvent motionEvent) {

//多点触摸的代码演示:

int num = motionEvent.getPointerCount();

int id = 0;

while (id < num){

int ptridx = motionEvent.getPointerId(id);

float x1 = motionEvent.getX(ptridx);

float y1 = motionEvent.getY(ptridx);

Log.d(TAG,"x1="+x1+",y1="+y1);//手指的屏幕坐标

float pressure = motionEvent.getPressure(ptridx);//压力

float size = motionEvent.getSize(ptridx);//手指尺寸

id++;//下一根手指

}

String action = "";

switch (motionEvent.getAction()){

case 0:

x =motionEvent.getX();

y = motionEvent.getY();

action = "按下";

break;

case 1:

if (motionEvent.getX() - x < -50){

action = "放开:往左边移动["+(motionEvent.getX() - x) +"]";//小于-50肯定是往左滑动

}else if (motionEvent.getX() - x > 50){

action = "放开:往右边移动["+(motionEvent.getX() - x) +"]";//大于50肯定是往右边滑动

}else {

action = "没有移动";

}

break;

case 2:

action = "移动";

break;

default:

action = "其他:"+motionEvent.getAction();

break;

}

String buff = "Aciton:"+action+"\n";

buff += "Location:x=>"+x+" y=>"+y+"\n";

buff += "EdgeFlags:"+motionEvent.getEdgeFlags()+"\n";

buff += "pressure:"+motionEvent.getPressure()+"\n";

buff += "size:"+motionEvent.getSize()+"\n";

buff += "downtime:"+motionEvent.getDownTime()+"\n";

buff += "eventtime:"+motionEvent.getEventTime()+"\n";

buff += "Elapsed:"+ (motionEvent.getEventTime() - motionEvent.getDownTime());

Log.d(TAG,buff.toString());

return true;

}

}

xml布局文件的代码:

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

android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"

android:paddingRight="@dimen/activity_horizontal_margin"

android:paddingTop="@dimen/activity_vertical_margin"

android:paddingBottom="@dimen/activity_vertical_margin"

android:id="@+id/relativeLayout"

tools:context=".MainActivity">

android:text=""

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:id="@+id/text2"/>

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:id="@+id/images1"

android:src="@drawable/wewer"

android:layout_marginTop="50dp"

android:scaleType="matrix"/>