用Kotlin帮我写一个Android自定义View进度条，进度条颜色是渐变色，宽高可以自行设置

好的，以下是用 Kotlin 编写的 Android 自定义 View 进度条的代码，进度条颜色为渐变色，宽高可以自行设置：

class GradientProgressBar @JvmOverloads constructor(
    context: Context,
    attrs: AttributeSet? = null,
    defStyleAttr: Int = 0
) : View(context, attrs, defStyleAttr) {

    private var progress = 0f
    private var progressColorStart = Color.parseColor("#FF5722")
    private var progressColorEnd = Color.parseColor("#FFC107")

    private val progressPaint = Paint(Paint.ANTI_ALIAS_FLAG).apply {
        style = Paint.Style.FILL
    }

    override fun onDraw(canvas: Canvas) {
        super.onDraw(canvas)

        val width = width.toFloat()
        val height = height.toFloat()

        val progressWidth = progress * width

        val gradient = LinearGradient(
            0f, 0f, width, 0f,
            progressColorStart, progressColorEnd, Shader.TileMode.CLAMP
        )

        progressPaint.shader = gradient

        canvas.drawRect(0f, 0f, progressWidth, height, progressPaint)
    }

    fun setProgressColor(startColor: Int, endColor: Int) {
        progressColorStart = startColor
        progressColorEnd = endColor
        invalidate()
    }

    fun setProgress(progress: Float) {
        this.progress = progress
        invalidate()
    }
}

希望这个代码对你有所帮助！