Android自定义View实现九宫格图形解锁(Kotlin版)

package com.example.kotlin_test
 
import android.content.Context
import android.graphics.Canvas
import android.graphics.Color
import android.graphics.Paint
import android.util.AttributeSet
import android.view.MotionEvent
import android.view.View
 

class MyLock : View {
    private var isInit=false
    private var mPoints:Array<Array<Point?>> = Array(3){Array<Point?>(3){null} }
    private var mSelectPoints=ArrayList<Point>()
    private var isTouch=false
    private var code= listOf(0,1,2,5,8)
 
    //画笔
    private lateinit var mNormalPaint:Paint
    private lateinit var mPressedPaint:Paint
    private lateinit var mErrorPaint: Paint
    private lateinit var mLinePaint: Paint
 
    //颜色
    private val mNormalColor=Color.BLACK
    private val mPressedColor=Color.GREEN
    private val mErrorColor=Color.RED
    private val mLineColor=Color.BLACK
 
    //外圆半径
    private var mDotRadius=0
 
    constructor(context: Context) : super(context)
    constructor(context: Context, attrs: AttributeSet) : super(context, attrs)
    constructor(context: Context, attrs: AttributeSet, defaultStyle: Int):super(context,attrs,defaultStyle)
 
    override fun onDraw(canvas: Canvas?) {
        //初始化
        if (!isInit) {
            initDot()
            initPaint()
            isInit=true
        }
 
        //绘制
        drawShow(canvas)
 
    }
 
    private fun drawShow(canvas: Canvas?) {
        for (i in 0..2) {
            for (j in 0..2) {
                var point = mPoints[i][j]
                when(point!!.status){
                    PointStatus.NORMAL->{
                        //先画外圆，再画内圆
                        canvas!!.drawCircle(point.centerX,point.centerY,
                            mDotRadius.toFloat(),mNormalPaint)
                        canvas!!.drawCircle(point.centerX,point.centerY,
                            mDotRadius.toFloat()/6,mNormalPaint)
                    }
                    PointStatus.PRESSED->{
                        canvas!!.drawCircle(point.centerX,point.centerY,
                            mDotRadius.toFloat(),mPressedPaint)
                        canvas!!.drawCircle(point.centerX,point.centerY,
                            mDotRadius.toFloat()/6,mPressedPaint)
                    }
                    PointStatus.ERROR->{
                        canvas!!.drawCircle(point.centerX,point.centerY,
                            mDotRadius.toFloat(),mErrorPaint)
                        canvas!!.drawCircle(point.centerX,point.centerY,
                            mDotRadius.toFloat()/6,mErrorPaint)
 
                    }
                }
 
            }
        }
 
        //画连线
        drawLine(canvas)
 
    }
 
    private fun drawLine(canvas: Canvas?) {
        if (mSelectPoints.size > 0) {
            var mLastPoint = mSelectPoints[0]
            //两点连线
            if (mSelectPoints.size > 1) {
                for (i in 1..mSelectPoints.size-1) {
                    var point = mSelectPoints[i]
                    realDrawLine(mLastPoint, point, canvas, mLinePaint)
                    mLastPoint=point
                }
            }
 
            //手指和某个点的连线
            var isInner=checkInRound(mLastPoint.centerX,mLastPoint.centerY,movingX,movingY,mDotRadius/6)
            if (!isInner&&isTouch) {
                realDrawLine(mLastPoint,Point(movingX,movingY,-1),canvas,mLinePaint)
            }
        }
 
 
    }
 
    private fun realDrawLine(
        mLastPoint: Point,
        point: Point,
        canvas: Canvas?,
        mLinePaint: Paint
    ) {
        //不是从圆心坐标开始画，而是距离圆心有一定的距离
        var dx=point.centerX-mLastPoint.centerX
        var dy=point.centerY-mLastPoint.centerY
        var pointDistance = Math.sqrt((dx * dx + dy * dy).toDouble())
 
        var offsetX = (dx / pointDistance) * (mDotRadius / 6)
        var offsetY=(dy/pointDistance)*(mDotRadius/6)
 
        canvas!!.drawLine((mLastPoint.centerX+offsetX).toFloat(),
            (mLastPoint.centerY+offsetY).toFloat(),
            (point.centerX-offsetX).toFloat(), (point.centerY-offsetY).toFloat(),mLinePaint)
    }
 
    private var movingX=0f
    private var movingY=0f
    override fun onTouchEvent(event: MotionEvent?): Boolean {
        movingX=event!!.x
        movingY=event.y
        when (event.action) {
            MotionEvent.ACTION_DOWN->{
                for (i in 0..mSelectPoints.size - 1) {
                    mSelectPoints[i].setStatusNormal()
                }
                mSelectPoints.clear()
                invalidate()
                //先判断是不是在圆内
                var dd=point
                if (dd != null) {
                    dd.setStatusPressed()
                    mSelectPoints.add(dd)
                    isTouch=true
                }
            }
            MotionEvent.ACTION_MOVE->{
                //先判断是不是在圆内
                var dd=point
                if (dd != null) {
                    dd.setStatusPressed()
                    if (!mSelectPoints.contains(dd)) {
                        mSelectPoints.add(dd)
                    }
                }
            }
            MotionEvent.ACTION_UP->{
                isTouch=false
                if (mSelectPoints.size == code.size) {
                    for (i in 0..mSelectPoints.size - 1) {
                        if (mSelectPoints[i].index != code[i]) {
                            for (i in 0..mSelectPoints.size - 1) {
                                //密码不对，设置为错误状态
                                mSelectPoints[i].setStatusError()
                            }
                            break
                        }
                    }
                } else {
                    for (i in 0..mSelectPoints.size - 1) {
                        mSelectPoints[i].setStatusError()
                    }
                }
            }
        }
 
        invalidate()
        return true
    }
 
    //扩展属性，遍历九个圆，看手指的按在哪个圆里面
    val point:Point?
    get() {
        for (i in 0..2) {
            for (j in 0..2) {
                var point = mPoints[i][j]
                if (checkInRound(point!!.centerX, point.centerY, movingX, movingY, mDotRadius)) {
                    return point
                }
            }
        }
        return null
    }
    //判断是不是在圆内
    private fun checkInRound(
        centerX: Float,
        centerY: Float,
        movingX: Float,
        movingY: Float,
        mDotRadius: Int
    ): Boolean {
        var isIn=Math.sqrt(((centerX-movingX)*(centerX-movingX)+(centerY-movingY)*(centerY-movingY)).toDouble())<mDotRadius
        return isIn
    }
 
    private fun initPaint() {
        //正常画笔
        mNormalPaint = Paint()
        mNormalPaint!!.color=mNormalColor
        mNormalPaint.style=Paint.Style.STROKE
        mNormalPaint.isAntiAlias=true
        mNormalPaint.strokeWidth=mDotRadius.toFloat()/12
 
        //按下画笔
        mPressedPaint = Paint()
        mPressedPaint!!.color=mPressedColor
        mPressedPaint.style=Paint.Style.STROKE
        mPressedPaint.isAntiAlias=true
        mPressedPaint.strokeWidth=mDotRadius.toFloat()/9
 
        //错误画笔
        mErrorPaint = Paint()
        mErrorPaint!!.color=mErrorColor
        mErrorPaint.style=Paint.Style.STROKE
        mErrorPaint.isAntiAlias=true
        mErrorPaint.strokeWidth=mDotRadius.toFloat()/12
 
        //连线画笔
        mLinePaint = Paint()
        mLinePaint!!.color=mLineColor
        mLinePaint.style=Paint.Style.STROKE
        mLinePaint.isAntiAlias=true
        mLinePaint.strokeWidth=mDotRadius.toFloat()/12
    }
 
    private fun initDot() {
        var width=this.width
        var height=this.height
 
        var offsetX=0f//九个宫格为正方形，距离布局左边的距离
        var offsetY=0f//九宫格为正方形，距离布局顶部的距离
 
        //兼容横竖屏
        if (width > height) {
            offsetX = (width - height).toFloat() / 2
            width = height
        } else {
            offsetY = (height - width).toFloat() / 2
 
        }
 
        //每个方格的大小
        var squareWidth=width/3
 
        mDotRadius=squareWidth/4
 
        //九个宫格，存于数组Point[3][3]
        mPoints[0][0] = Point(squareWidth/2+offsetX,squareWidth/2+offsetY,0)
        mPoints[0][1] = Point(squareWidth*3/2+offsetX,squareWidth/2+offsetY,1)
        mPoints[0][2] = Point(squareWidth*5/2+offsetX,squareWidth/2+offsetY,2)
        mPoints[1][0] = Point(squareWidth/2+offsetX,squareWidth*3/2+offsetY,3)
        mPoints[1][1] = Point(squareWidth*3/2+offsetX,squareWidth*3/2+offsetY,4)
        mPoints[1][2] = Point(squareWidth*5/2+offsetX,squareWidth*3/2+offsetY,5)
        mPoints[2][0] = Point(squareWidth/2+offsetX,squareWidth*5/2+offsetY,6)
        mPoints[2][1] = Point(squareWidth*3/2+offsetX,squareWidth*5/2+offsetY,7)
        mPoints[2][2] = Point(squareWidth*5/2+offsetX,squareWidth*5/2+offsetY,8)
 
    }
 
    //圆的状态
    enum class PointStatus{
        NORMAL,PRESSED,ERROR
    }
 
    class Point(var centerX: Float, var centerY: Float, var index: Int){
        //默认状态
        var status = PointStatus.NORMAL
 
        fun setStatusNormal() {
            status=PointStatus.NORMAL
        }
 
        fun setStatusPressed() {
            status=PointStatus.PRESSED
        }
        fun setStatusError() {
            status=PointStatus.ERROR
        }
    }
 
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">
 
 
    <com.example.kotlin_test.MyLock
        android:layout_width="match_parent"
        android:layout_height="match_parent" />
</LinearLayout>