kotlin转盘抽奖代码

根据提供的引用内容，我们可以看到有两个与Kotlin转盘抽奖相关的引用。其中，引用提供了一个彩色转盘类的继承，可以绘制圆盘并实现转盘抽奖的效果。而引用则提供了一个名为StatisticRingChart的自定义视图类，可以实现类似于转盘抽奖的统计环形图效果。
以下是一个基于引用的Kotlin转盘抽奖代码的示例：
class LuckyWheelView(context: Context, attrs: AttributeSet) : View(context, attrs) {

private var mColors = intArrayOf(Color.RED, Color.YELLOW, Color.GREEN, Color.BLUE, Color.CYAN, Color.MAGENTA)
private var mPaint = Paint(Paint.ANTI_ALIAS_FLAG)
private var mRectF = RectF()
private var mRadius = 0f
private var mStartAngle = 0f
private var mSweepAngle = 0f
private var mItemCount = 6
private var mItemTexts = arrayOf("Item 1", "Item 2", "Item 3", "Item 4", "Item 5", "Item 6")
private var mTextPaint = Paint(Paint.ANTI_ALIAS_FLAG)
private var mTextSize = 0f
private var mCenterX = 0f
private var mCenterY = 0f

init {
mPaint.style = Paint.Style.FILL
mTextPaint.color = Color.WHITE
mTextPaint.textAlign = Paint.Align.CENTER
}

override fun onMeasure(widthMeasureSpec: Int, heightMeasureSpec: Int) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec)
val width = MeasureSpec.getSize(widthMeasureSpec)
val height = MeasureSpec.getSize(heightMeasureSpec)
val size = Math.min(width, height)
setMeasuredDimension(size, size)
}

override fun onSizeChanged(w: Int, h: Int, oldw: Int, oldh: Int) {
super.onSizeChanged(w, h, oldw, oldh)
mRadius = (Math.min(w, h) / 2 * 0.8).toFloat()
mCenterX = (w / 2).toFloat()
mCenterY = (h / 2).toFloat()
mTextSize = mRadius / 8
mTextPaint.textSize = mTextSize
mRectF.left = mCenterX - mRadius
mRectF.top = mCenterY - mRadius
mRectF.right = mCenterX + mRadius
mRectF.bottom = mCenterY + mRadius
}

override fun onDraw(canvas: Canvas) {
super.onDraw(canvas)
canvas.drawColor(Color.WHITE)
mSweepAngle = 360f / mItemCount
for (i in 0 until mItemCount) {
mPaint.color = mColors[i % mColors.size]
canvas.drawArc(mRectF, mStartAngle, mSweepAngle, true, mPaint)
drawText(canvas, mStartAngle, mItemTexts[i])
mStartAngle += mSweepAngle
}
}

private fun drawText(canvas: Canvas, angle: Float, text: String) {
val path = Path()
path.addArc(mRectF, angle, mSweepAngle)
val textWidth = mTextPaint.measureText(text)
val hOffset = (mRadius * Math.PI / mItemCount - textWidth) / 2
val vOffset = mRadius / 2 / 6
canvas.drawTextOnPath(text, path, hOffset.toFloat(), vOffset.toFloat(), mTextPaint)
}
}
登录后复制
该代码实现了一个LuckyWheelView类，继承自View类，可以在Android应用中实现一个转盘抽奖的效果。在该类中，我们定义了转盘的颜色、半径、起始角度、扫描角度、选项个数、选项文本等属性，并在onMeasure()和onSizeChanged()方法中计算了转盘的大小和位置。在onDraw()方法中，我们使用Canvas绘制了转盘的扇形区域，并在每个扇形区域中绘制了对应的选项文本。最后，我们使用drawTextOnPath()方法将文本沿着扇形区域的弧线绘制出来，实现了转盘抽奖的效果。