Dialog动画相关

最近需求一个问题，想要在dialog消失时增加动画，之前如上一个文章中遇到的，但是最后改了实现方式，要求在特定的地方缩放，原来的dialog高度是wrap_content的，这样是无法实现的，因此首先需要将dialog的layout文件从wrap_content，改成match_parent，同时设置最外层布局背景透明。在dialog.show()之后，重新设置窗口属性

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:gravity="center"
    android:clipChildren="false"
    android:layoutDirection="ltr">
 
此处省略内部内容
 
 
 
</RelativeLayout>

        dialog?.show()
        dialog?.apply {
            window?.setLayout(
                WindowManager.LayoutParams.MATCH_PARENT,
                WindowManager.LayoutParams.MATCH_PARENT
            )
        }

紧接着我们就可以使用动画了，尤其是平移动画，原来dialog是wrap_content的时候，如何平移超过view，就会消失。当dialog变成match_parent后，就可以正常使用平移动画了。

思路：根据位置计算平移的距离进行平移，同时缩放

    private fun setAnim(dialog: Dialog) {
        dialog.apply {
            val animView = findViewById<View>(R.id.limited_layout)
            val height = animView?.height
            //此处是在计算相应的距离等内容
            val retainHeight = (screenHeight(context) - height!!) / 2 - DensityUtil.dp2px(
                ApplicationHelper.getInstance().context,
                84f
            ) - getStatusBarHeight(context)
            val topHeight = DensityUtil.dp2px(
                ApplicationHelper.getInstance().context,
                80f
            )
            val transHeight = retainHeight - topHeight - DensityUtil.dp2px(
                ApplicationHelper.getInstance().context,
                28f
            ).toFloat()
            val scaleAnimation = if (retainHeight < topHeight
            ) {
                ScaleAnimation(
                    1f, 0f,
                    1f, 0f,
                    Animation.RELATIVE_TO_SELF, 1f,
                    Animation.RELATIVE_TO_SELF,
                    (
                        (
                            topHeight + DensityUtil.dp2px(
                                ApplicationHelper.getInstance().context,
                                28f
                            ) - retainHeight
                            ) / height.toFloat()
                        )
                )
            } else {
                ScaleAnimation(
                    1f, 0f,
                    1f, 0f,
                    Animation.RELATIVE_TO_SELF, 1f,
                    Animation.RELATIVE_TO_SELF, 0f
                )
            }
 
            val translationAnimator = if (retainHeight > topHeight) {
                TranslateAnimation(
                    0f,
                    0f,
                    0f,
                    -transHeight
                )
            } else {
                null
            }
            translationAnimator?.let {
                val animationSet = AnimationSet(true)
                scaleAnimation.duration = 300
                animationSet.addAnimation(scaleAnimation)
 
                val alphaAnimation = AlphaAnimation(1f, 0f)
                alphaAnimation.duration = 300
                it.duration = 300
                animationSet.addAnimation(it)
                animationSet.addAnimation(alphaAnimation)
                animView.startAnimation(animationSet)
                animationSet.setAnimationListener(object : Animation.AnimationListener {
                    override fun onAnimationStart(animation: Animation?) {
                        // 动画开始时的操作
                    }
 
                    override fun onAnimationEnd(animation: Animation?) {
                        mLimitedDialog?.let { dismiss() }
                    }
 
                    override fun onAnimationRepeat(animation: Animation?) {
                        // 动画重复时的操作
                    }
                })
            } ?: run {
                val animationSet = AnimationSet(true)
                scaleAnimation.duration = 300
                animationSet.addAnimation(scaleAnimation)
 
                val alphaAnimation = AlphaAnimation(1f, 0f)
                alphaAnimation.duration = 300
                animationSet.addAnimation(alphaAnimation)
                animView.startAnimation(animationSet)
                animationSet.setAnimationListener(object : Animation.AnimationListener {
                    override fun onAnimationStart(animation: Animation?) {
                        // 动画开始时的操作
                    }
 
                    override fun onAnimationEnd(animation: Animation?) {
                        mLimitedDialog?.let { dismiss() }
                    }
 
                    override fun onAnimationRepeat(animation: Animation?) {
                    }
                })
            }
        }
    }