本文实例为大家分享了android实现可拖动的浮动view，供大家参考，具体内容如下
业务来源
页面最小化后，需要出现一个浮动 view 告知用户，防止遮挡视线，需要对 view 做可滑动处理
已知会遇到的问题
1.view 的依赖的布局类型未知【为了后续方便扩展】
外界传递 ViewGroup 自己本身继承 LinearLayout【或者其他 ViewGroup 】
class FloatChannelView(var mContext: Context?, var viewGroup: ViewGroup) : LinearLayout(mContext){
private var mIcon: ImageView = ImageView(context)
private var mName: TextView = TextView(context)
private var mClose: ImageView = ImageView(context)
private var iconWH = dip2Px(38)
private var groupPadding = dip2Px(3)
private var mViewGroupH = dip2Px(44)
private var mViewGroupW = dip2Px(152)
private var mBoundaryLeft: Float
private var mBoundaryTop: Float
private var mBoundaryRight: Float
private var mBoundaryBottom: Float
private var mScreenWidth = getScreenWidth() // 获取屏幕宽高
private var mScreenHeight = getScreenHeight()
private var mDownEventX: Float = 0f // 相对控件的x
private var mDownEventY: Float = 0f
private var mDownX: Float = 0f // 相对屏幕所在的 x
private var mDownY: Float = 0f
private var mListener: OnClickListener? = null
private var mIsStartAnimation: Boolean = false
private val mDefaultMargin = dip2Px(12)
private var mMarginLeft = mDefaultMargin
private var mMarginTop = mDefaultMargin
private var mMarginRight = mDefaultMargin
private var mMarginBottom = mDefaultMargin
init {
layoutParams = LayoutParams(mViewGroupW, mViewGroupH)
setPadding(groupPadding, groupPadding, groupPadding, groupPadding)
setBackgroundResource(R.drawable.backage) // 建议加一些透明
orientation = HORIZONTAL
gravity = Gravity.CENTER_VERTICAL
mBoundaryLeft = mMarginLeft.toFloat()
mBoundaryTop = mMarginTop.toFloat()
mBoundaryRight = mScreenWidth - mMarginRight.toFloat()
mBoundaryBottom = (mScreenHeight - mMarginBottom - dip2Px(85)).toFloat()
setView()
}
}2.拖动事件影响点击，事件分发处理。
override fun onTouchEvent(event: MotionEvent?): Boolean {
if (mIsStartAnimation) { // 动画正在进行无需处理 onTouch
return true
}
if (event == null) {
return super.onTouchEvent(event)
}
mIsOnTouch = true
//悬浮区域左上角坐标
val x = x
val y = y
//悬浮区域宽高
val width = mViewGroupW
val height = mViewGroupH
when (event.actionMasked) {
ACTION_DOWN -> {
//点击位置坐标
mDownEventX = event.x
mDownEventY = event.y
mDownX = x
mDownY = y
}
ACTION_UP -> {
mUpTime = System.currentTimeMillis()
if (mIsMove && abs(mDownX - x) <= 8f && abs(mDownY - y) <= 8f) {
mListener?.onClick(this)
}
mIsMove = false
// 抬起后处理边界溢出问题
resilienceAnimation(x, y, x mViewGroupW, y mViewGroupH)
}
ACTION_MOVE -> {
val changeX = event.x.toInt() - mDownEventX
val changeY = event.y.toInt() - mDownEventY
mIsMove = true
if (changeX == 0f && changeY == 0f) {
return super.onTouchEvent(event)
}
val left = (x changeX).toInt()
val top = (y changeY).toInt()
val right = left mViewGroupW
val bottom = top mViewGroupH
layout(left, top, right, bottom)
}
}
return true
}3.拖到边界问题。
拖出边界后做了回弹处理
/**
* 超出边界回弹
* @param left 当前 x 方向位置
* @param right 当前 y 方向位置
*/
private fun resilienceAnimation(left: Float, top: Float, right: Float, bottom: Float) {
var startX = 0f
var resilienceX = 0f
if (mBoundaryLeft <= left && right <= mBoundaryRight) { // x 方向在范围内
// 不处理
} else if (mBoundaryLeft > left) { // left 溢出
startX = 0f
resilienceX = mBoundaryLeft - left
} else { // right 方向底部溢出
startX = 0f
resilienceX = mBoundaryRight - right
}
var startY = 0f
var resilienceY = 0f
if (mBoundaryTop <= top && bottom <= mBoundaryBottom) { // y 方向在范围内
// 不处理
} else if (mBoundaryTop > top) { // top 溢出
startY = 0f
resilienceY = mBoundaryTop - top
} else { // bottom 溢出
startY = 0f
resilienceY = mBoundaryBottom - bottom
}
if (resilienceX == 0f && resilienceY == 0f) { // 在范围内无需回弹
return
}
// 超出边界回弹
val phaseFirstDuration: Long = 400
var oAnimPhaseFirstTUpX: ObjectAnimator? = null
if (resilienceX != 0f) {
oAnimPhaseFirstTUpX = ObjectAnimator.ofFloat(this, "translationX", startX, resilienceX)
.setDuration(phaseFirstDuration)
}
var oAnimPhaseFirstTUpY: ObjectAnimator? = null
if (resilienceY != 0f) {
oAnimPhaseFirstTUpY = ObjectAnimator.ofFloat(this, "translationY", startY, resilienceY)
.setDuration(phaseFirstDuration)
}
val animatorSet = AnimatorSet()
if (oAnimPhaseFirstTUpX != null && oAnimPhaseFirstTUpY != null) {
animatorSet.play(oAnimPhaseFirstTUpX).with(oAnimPhaseFirstTUpY)
} else if (oAnimPhaseFirstTUpX != null) {
animatorSet.play(oAnimPhaseFirstTUpX)
} else {
animatorSet.play(oAnimPhaseFirstTUpY)
}
animatorSet.childAnimations[animatorSet.childAnimations.size - 1].addListener(object : Animator.AnimatorListener {
override fun onAnimationStart(animation: Animator?) {
mIsStartAnimation = true
}
override fun onAnimationEnd(animation: Animator?) {
var l = left
var t = top
var r = right
var b = bottom
when {
mBoundaryLeft > left -> { // x左边溢出
l = mBoundaryLeft
r = mBoundaryLeft mViewGroupW
}
mBoundaryRight < right -> { // x右边溢出
l = mBoundaryRight - mViewGroupW
r = mBoundaryRight
}
else -> { // x方向未溢出
}
}
when {
mBoundaryTop > top -> { // y 顶部溢出
t = mBoundaryTop
b = mBoundaryTop mViewGroupH
}
mBoundaryBottom < bottom -> { // y 底部溢出
t = mBoundaryBottom - mViewGroupH
b = mBoundaryBottom
}
else -> { // y方向未溢出
}
}
// 只进行偏移，实际位置未变化，需要重置偏移量，并重绘
this@FloatChannelView.translationX = 0f
this@FloatChannelView.translationY = 0f
layout(l.toInt(), t.toInt(), r.toInt(), b.toInt())
mMarginLeft = l.toInt()
mMarginTop = t.toInt()
mIsStartAnimation = false
}
override fun onAnimationCancel(animation: Animator?) {}
override fun onAnimationRepeat(animation: Animator?) {}
})
animatorSet.start()以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持Devmax。