Android实现长按圆环动画View效果的思路代码

val touchMax = 50
    var lastX = 0
    var lastY = 0
    circleView.setOnTouchListener(object : View.OnTouchListener{
      override fun onTouch(p0: View?, motionEvent: MotionEvent): Boolean {
        val endTime: Long
        val x = motionEvent.x
        val y = motionEvent.y
        when (motionEvent.action) {
          MotionEvent.ACTION_DOWN -> {
            startTime = System.currentTimeMillis()
            lastX = x.toInt()
            lastY = y.toInt()
            circleView.startAnim()
          }
          MotionEvent.ACTION_UP -> {
            endTime = System.currentTimeMillis()
            val during = endTime - startTime
            if (during < App.LONG_CLICK_TIME) {
              circleView.cancelAnim()
              circleView.clearAll()
            }else{
              playMaxWarn()
            }
          }
          MotionEvent.ACTION_MOVE -> {
            if (abs(lastX - x) > touchMax || abs(lastY - y) > touchMax) {
              circleView.clearAll()
            }
          }
        }
        return false
      }
    })

fun startAnim() {
    isClear = false
    valueAnimator = ValueAnimator.ofFloat(0F, 359.9999F)
    valueAnimator!!.duration = App.LONG_CLICK_TIME
    valueAnimator!!.addUpdateListener { animation ->
      mProgress = animation.animatedValue as Float
      invalidate()
    }
    valueAnimator!!.start()
  }

package cn.xmliu.melongo.view

import android.animation.ValueAnimator
import android.content.Context
import android.graphics.*
import android.util.AttributeSet
import android.view.View
import androidx.core.content.ContextCompat
import cn.xmliu.melongo.App
import cn.xmliu.melongo.R

/**
 * Date: 2020/8/12 13:21
 * Email: diyangxia@163.com
 * Description: 长按动画View
 */
class LongCircleView(context: Context?, attrs: AttributeSet?) : View(context, attrs) {

  /**
   * 画笔
   */
  private val paint = Paint()
  private var arcPath: Path? = null
  private var rectF: RectF? = null
  private var lineColor = 0

  /**
   * 中心点坐标、半径
   */
  private var centerX: Float? = null
  private var centerY: Float? = null
  private var radius: Float? = null

  private var left = -1F
  private var top = -1F
  private var right = -1F
  private var bottom = -1F
  private val offset = 10

  private var mProgress = -1F
  private var valueAnimator: ValueAnimator ?= null
  private var isClear = true

  init {
    lineColor = ContextCompat.getColor(context!!, R.color.red)

  }

  override fun onSizeChanged(w: Int, h: Int, oldw: Int, oldh: Int) {
    super.onSizeChanged(w, h, oldw, oldh)
    centerX = width / 2.toFloat()
    centerY = height / 2.toFloat()
    radius = height / 2.toFloat()
    left = centerX!! - radius!! + offset
    top = centerY!! - radius!! + offset
    right = centerX!! + radius!! - offset
    bottom = centerY!! + radius!! - offset

    rectF = RectF(left, top, right, bottom)
    arcPath = Path()
  }

  override fun onDraw(canvas: Canvas?) {
    super.onDraw(canvas)
    paint.isAntiAlias = true
    paint.color = lineColor
    paint.style = Paint.Style.STROKE
    paint.strokeWidth = 10F
    arcPath!!.rewind() // 清除直线数据，保留数据结构，方便快速重用
    if(isClear) return
    arcPath!!.arcTo(rectF!!, 270F, mProgress)
    canvas?.drawPath(arcPath!!, paint)
  }

  fun startAnim() {
    isClear = false
    valueAnimator = ValueAnimator.ofFloat(0F, 359.9999F)
    valueAnimator!!.duration = App.LONG_CLICK_TIME
    valueAnimator!!.addUpdateListener { animation ->
      mProgress = animation.animatedValue as Float
      invalidate()
    }
    valueAnimator!!.start()
  }

  fun cancelAnim(){
    valueAnimator!!.cancel()
  }

  fun clearAll() {
    isClear = true
    invalidate()
  }
}

<RelativeLayout
        android:layout_width="wrap_content"
        android:layout_marginTop="5dp"
        android:layout_height="wrap_content">

        <LinearLayout
          android:id="@+id/flashLayout"
          android:layout_centerInParent="true"
          android:layout_width="70dp"
          android:layout_height="70dp"
          android:background="@drawable/btn_circle_white"
          android:gravity="center_horizontal"
          android:orientation="vertical">

          <ImageView
            android:id="@+id/flashIV"
            android:layout_width="40dp"
            android:layout_height="40dp"
            android:padding="7dp"
            android:src="@drawable/menu_flash_black"
            android:text="闪灯开"
            android:tint="@color/main_color" />

          <TextView
            android:id="@+id/flashTV"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="闪灯"
            android:textColor="@color/main_color" />
        </LinearLayout>

        <cn.xmliu.melongo.view.LongCircleView
          android:id="@+id/circleView"
          android:layout_width="80dp"
          android:layout_height="80dp" />
      </RelativeLayout>

val touchMax = 50
    var lastX = 0
    var lastY = 0
    circleView.setOnTouchListener(object : View.OnTouchListener{
      override fun onTouch(p0: View?, motionEvent: MotionEvent): Boolean {
        val endTime: Long
        val x = motionEvent.x
        val y = motionEvent.y
        when (motionEvent.action) {
          MotionEvent.ACTION_DOWN -> {
            startTime = System.currentTimeMillis()
            lastX = x.toInt()
            lastY = y.toInt()
            circleView.startAnim()
          }
          MotionEvent.ACTION_UP -> {
            endTime = System.currentTimeMillis()
            val during = endTime - startTime
            if (during < App.LONG_CLICK_TIME) {
              circleView.cancelAnim()
              circleView.clearAll()
            }else{
              flashTV.text = "OK"
            }
          }
          MotionEvent.ACTION_MOVE -> {
            if (abs(lastX - x) > touchMax || abs(lastY - y) > touchMax) {
              circleView.clearAll()
            }
          }
        }
        return false
      }
    })