1.获取点击xy轴的下标，实现触摸效果。
获取XY画一个圆并且自动从下变大，直到消失不见。
效果图如下：
代码如下：
1.写一个实体类，用于存写触摸点击的XY轴下表，并根据获得的下标用半径把圆画出来，半径默认为0
package com.example.android_pointstouch;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.os.Handler;
import android.os.Message;
import android.support.annotation.Nullable;
import android.util.AttributeSet;
import android.view.View;
import java.util.Random;
/**
* Created by Administrator on 2017/7/9 0009.
*/
public class Circle {
public float x;
public float y;
public int r;
public int pointId;
private int red;
private int green;
private int blue;
Random random=new Random();
public Circle(float x,float y,int r,int pointId){
this.x=x;
this.y=y;
this.r=r;
this.pointId=pointId;
this.red=random.nextInt(255);
this.green=random.nextInt(255);
this.blue=random.nextInt(255);
}
//画圆
public void drawSelf(Canvas canvas, Paint paint){
paint.setColor(Color.rgb(red,green,blue));//颜色
canvas.drawCircle(x,y,r,paint);
paint.setStyle(Paint.Style.STROKE);
}
}2.利用线程的调用改变圆半径的大小
package com.example.android_pointstouch;
import android.content.Context;
import android.content.Intent;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.os.Handler;
import android.os.Message;
import android.support.annotation.Nullable;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
/**
* Created by Administrator on 2017/7/9 0009.
*/
public class MyButton extends View {
private List<Circle> circleList=new ArrayList<>();
private float x;
private float y;
private int indexid;
int i=0;
public MyButton(Context context) {
super(context);
}
public MyButton(Context context, @Nullable AttributeSet attrs) {
super(context, attrs);
}
public MyButton(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
}
public MyButton(Context context, @Nullable AttributeSet attrs, int defStyleAttr, int defStyleRes) {
super(context, attrs, defStyleAttr, defStyleRes);
}
//画画
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
Paint paint=new Paint();
paint.setStyle(Paint.Style.STROKE);
for (Circle circle : circleList) {
circle.r+=10;
circle.drawSelf(canvas,paint);
}
}
//触摸
@Override
public boolean onTouchEvent(MotionEvent event) {
int action = event.getAction();
//手指的下标Index
int pointIndex = action >> 8;
int action_code= action&0xff;
x = event.getX(pointIndex);//X轴
y = event.getY(pointIndex);//Y轴
indexid = event.getPointerId(pointIndex);//触摸的下标
// Log.i("text","pointIndex="+pointIndex+"action_code="+action_code+"indexid="+indexid);
if(action_code>=5){
action_code-=5;
}
switch (action_code){
case MotionEvent.ACTION_DOWN://点击
i++;
Circle circle=new Circle(x,y,0,indexid);//进来一次就NEW一个对象
circleList.add(circle);//加入集合
new my().start();//启动线程
break;
case MotionEvent.ACTION_UP://移开
//circleList.remove(delete(indexid));
break;
case MotionEvent.ACTION_MOVE://移动
/* for (int i = 0; i <event.getPointerCount() ; i++) {
int id= event.getPointerId(i);
delete(id).x=event.getX(i);
delete(id).y=event.getY(i);
}*/
break;
}
invalidate();
return true;
}
//移除
public Circle delete(int indexid){
for (Circle circle : circleList) {
if(circle.pointId==indexid){
return circle;
}
}
return null;
}
//线程 改变圆大小
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
class my extends Thread{
@Override
public void run() {
for (int i = 0; i <10; i++) {
try {
sleep(110);
postInvalidate();//回调
} catch (InterruptedException e) {
e.printStackTrace();
}
if(i==9){
circleList.remove(0);
}
}
}
}
}
