android怎么实现可拖动的浮动view

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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     privateval 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()

到此，相信大家对"android怎么实现可拖动的浮动view"有了更深的了解，不妨来实际操作一番吧！这里是网站，更多相关内容可以进入相关频道进行查询，关注我们，继续学习！