• Android-自定义三角形评分控件

    效果图

    序言

    在移动应用开发中，显示数据的方式多种多样，直观的图形展示常常能带给用户更好的体验。本文将介绍如何使用Flutter创建一个自定义三角形纬度评分控件，该控件可以通过动画展示评分的变化，让应用界面更加生动。

    实现思路及步骤

    1. 定义控件属性：首先需要定义控件的基本属性，如宽度、高度、最大评分以及每个顶点的评分值。
    2. 自定义绘制：使用自定义View绘制三角形和评分三角形，并在顶点处绘制空心圆点。
    3. 实现动画效果：使用属性动画ValueAnimator来控制评分动画，使每个顶点的评分从0逐渐增加到对应的评分值。

    代码实现

    定义自定义属性和布局文件

    在res/values/attrs.xml中定义自定义属性：

       <declare-styleable name="TriangleRatingAnimView">
        <attr name="maxRating" format="integer" />
        <attr name="upRating" format="integer" />
        <attr name="leftRating" format="integer" />
        <attr name="rightRating" format="integer" />
        <attr name="strokeColor" format="color" />
        <attr name="strokeWidth" format="dimension" />
        <attr name="ratingStrokeColor" format="color" />
        <attr name="ratingStrokeWidth" format="dimension" />
    </declare-styleable>

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    创建自定义View类

    首先，创建一个自定义View类TriangleRatingAnimView，用于绘制三角形和动画效果。

    package com.yxlh.androidxy.demo.ui.rating

import android.animation.ValueAnimator
import android.content.Context
import android.graphics.Canvas
import android.graphics.Color
import android.graphics.Paint
import android.graphics.Path
import android.util.AttributeSet
import android.util.TypedValue
import android.view.View
import androidx.core.content.withStyledAttributes
import androidx.core.graphics.ColorUtils
import androidx.interpolator.view.animation.LinearOutSlowInInterpolator
import com.yxlh.androidxy.R


fun Context.dpToPx(dp: Float): Float {
    return TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dp, resources.displayMetrics)
}

/**
 * 三角形评分控件
 * https://github.com/yixiaolunhui/AndroidXY
 */
class TriangleRatingAnimView @JvmOverloads constructor(
    context: Context,
    attrs: AttributeSet? = null,
    defStyleAttr: Int = 0,
) : View(context, attrs, defStyleAttr) {

    var maxRating: Int = 5
        set(value) {
            field = value
            invalidate()
        }
    var upRating: Int = 0
        set(value) {
            field = value
            animateRating()
        }
    var leftRating: Int = 0
        set(value) {
            field = value
            animateRating()
        }
    var rightRating: Int = 0
        set(value) {
            field = value
            animateRating()
        }
    private var strokeColor: Int = Color.GRAY
    private var strokeWidth: Float = context.dpToPx(1.5f)
    private var ratingStrokeColor: Int = Color.RED
    private var ratingStrokeWidth: Float = context.dpToPx(2.5f)
    private var animatedUpRating = 0
    private var animatedLeftRating = 0
    private var animatedRightRating = 0

    private val paint = Paint(Paint.ANTI_ALIAS_FLAG).apply {
        style = Paint.Style.STROKE
        color = strokeColor
        strokeWidth = this@TriangleRatingAnimView.strokeWidth
    }

    private val outerPaint = Paint(Paint.ANTI_ALIAS_FLAG).apply {
        style = Paint.Style.STROKE
        color = ratingStrokeColor
        strokeWidth = this@TriangleRatingAnimView.ratingStrokeWidth
    }

    private val fillPaint = Paint(Paint.ANTI_ALIAS_FLAG).apply {
        style = Paint.Style.FILL
        color = ColorUtils.setAlphaComponent(ratingStrokeColor, (0.3 * 255).toInt())
    }
    private val circlePaint = Paint(Paint.ANTI_ALIAS_FLAG).apply {
        style = Paint.Style.STROKE
        color = ratingStrokeColor
        strokeWidth = context.dpToPx(1.5f)
    }
    private val circleFillPaint = Paint(Paint.ANTI_ALIAS_FLAG).apply {
        style = Paint.Style.FILL
        color = Color.WHITE
    }

    init {
        context.withStyledAttributes(attrs, R.styleable.TriangleRatingAnimView) {
            maxRating = getInt(R.styleable.TriangleRatingAnimView_maxRating, 5)
            upRating = getInt(R.styleable.TriangleRatingAnimView_upRating, 0)
            leftRating = getInt(R.styleable.TriangleRatingAnimView_leftRating, 0)
            rightRating = getInt(R.styleable.TriangleRatingAnimView_rightRating, 0)
            strokeColor = getColor(R.styleable.TriangleRatingAnimView_strokeColor, Color.GRAY)
            strokeWidth = context.dpToPx(getDimension(R.styleable.TriangleRatingAnimView_strokeWidth, 2f))
            ratingStrokeColor = getColor(R.styleable.TriangleRatingAnimView_ratingStrokeColor, Color.RED)
            ratingStrokeWidth = context.dpToPx(getDimension(R.styleable.TriangleRatingAnimView_ratingStrokeWidth, 4f))
        }
    }

    private fun animateRating() {
        val animator = ValueAnimator.ofFloat(0f, 1f).apply {
            duration = 300
            interpolator = LinearOutSlowInInterpolator()
            addUpdateListener { animation ->
                val animatedValue = animation.animatedValue as Float
                animatedUpRating = (upRating * animatedValue).toInt()
                animatedLeftRating = (leftRating * animatedValue).toInt()
                animatedRightRating = (rightRating * animatedValue).toInt()
                invalidate()
            }
        }
        animator.start()
    }

    override fun onDraw(canvas: Canvas) {
        super.onDraw(canvas)
        val width = measuredWidth.toFloat()
        val height = measuredHeight.toFloat()
        val circleRadius = context.dpToPx(5f)
        val padding = circleRadius + context.dpToPx(2f)

        val p1 = width / 2 to padding
        val p2 = padding to height - padding
        val p3 = width - padding to height - padding

        // 绘制外部三角形
        val path = Path().apply {
            moveTo(p1.first, p1.second)
            lineTo(p2.first, p2.second)
            lineTo(p3.first, p3.second)
            close()
        }
        canvas.drawPath(path, paint)

        val centroidX = (p1.first + p2.first + p3.first) / 3
        val centroidY = (p1.second + p2.second + p3.second) / 3

        // 绘制顶点到重心的连线
        canvas.drawLine(p1.first, p1.second, centroidX, centroidY, paint)
        canvas.drawLine(p2.first, p2.second, centroidX, centroidY, paint)
        canvas.drawLine(p3.first, p3.second, centroidX, centroidY, paint)

        val dynamicP1 =
            centroidX + (p1.first - centroidX) * (animatedUpRating / maxRating.toFloat()) to centroidY + (p1.second - centroidY) * (animatedUpRating / maxRating.toFloat())
        val dynamicP2 =
            centroidX + (p2.first - centroidX) * (animatedLeftRating / maxRating.toFloat()) to centroidY + (p2.second - centroidY) * (animatedLeftRating / maxRating.toFloat())
        val dynamicP3 =
            centroidX + (p3.first - centroidX) * (animatedRightRating / maxRating.toFloat()) to centroidY + (p3.second - centroidY) * (animatedRightRating / maxRating.toFloat())

        // 绘制内部动态三角形
        val ratingPath = Path().apply {
            moveTo(dynamicP1.first, dynamicP1.second)
            lineTo(dynamicP2.first, dynamicP2.second)
            lineTo(dynamicP3.first, dynamicP3.second)
            close()
        }
        canvas.drawPath(ratingPath, outerPaint)
        canvas.drawPath(ratingPath, fillPaint)

        // 绘制动态点上的空心圆
        canvas.drawCircle(dynamicP1.first, dynamicP1.second, circleRadius, circlePaint)
        canvas.drawCircle(dynamicP1.first, dynamicP1.second, circleRadius - context.dpToPx(1.5f), circleFillPaint)
        canvas.drawCircle(dynamicP2.first, dynamicP2.second, circleRadius, circlePaint)
        canvas.drawCircle(dynamicP2.first, dynamicP2.second, circleRadius - context.dpToPx(1.5f), circleFillPaint)
        canvas.drawCircle(dynamicP3.first, dynamicP3.second, circleRadius, circlePaint)
        canvas.drawCircle(dynamicP3.first, dynamicP3.second, circleRadius - context.dpToPx(1.5f), circleFillPaint)
    }
}


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    定义Activity界面xml文件

    在res/layout/activity_rating.xml中使用自定义View：
    定义RatingActivity
    package com.yxlh.androidxy.demo.ui.rating

import android.os.Bundle
import androidx.appcompat.app.AppCompatActivity
import com.yxlh.androidxy.databinding.ActivityRatingBinding
import kotlin.random.Random

class RatingActivity : AppCompatActivity() {

    private var binding: ActivityRatingBinding? = null

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        binding = ActivityRatingBinding.inflate(layoutInflater)
        setContentView(binding?.root)
        binding?.randomizeButton?.setOnClickListener {
            randomizeRatings()
        }
    }

    private fun randomizeRatings() {
        val random = Random(System.currentTimeMillis())
        val maxRating = 5 + random.nextInt(6)
        val upRating = 1 + random.nextInt(maxRating)
        val leftRating = 1 + random.nextInt(maxRating)
        val rightRating = 1 + random.nextInt(maxRating)
        binding?.triangleRatingAnimView?.apply {
            this.maxRating = maxRating
            this.upRating = upRating
            this.leftRating = leftRating
            this.rightRating = rightRating
            invalidate()
        }
    }
}


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    通过以上步骤和代码，我们可以创建一个带动画效果的三角形纬度评分控件，使评分展示更加生动和直观。

    详情可见：github.com/yixiaolunhui/AndroidXY

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  • 原文地址：https://blog.csdn.net/u014741977/article/details/139033869