Android 实现多点触摸画圆

实现效果图：

 

想要实现上述效果，非常的简单，我在这里就直接用代码给大家讲解了：

首先我们要写一个圆的类：

 

package com.example.android19_zhangkai_pointstouch;

import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;

import java.util.Random;

/**
 * Created by Administrator on 2017/7/9 0009.
 */

public class Circle {
    public float x;
    public float y;
    public int r=100;
    public int pointId;

    //随机三原色
    int red;
    int green;
    int blue;
    Random random=new Random();

    public Circle(float x, float y, int pointId){
        this.x = x;
        this.y = y;
        this.pointId = pointId;
        red=random.nextInt(255);
        green=random.nextInt(255);