BottomSheetDialogFragment 默认的显示方式，是有一小段是要自己滑上来的，那么如何让他显示完全呢。。。直接上代码吧，原理啥的大家也估计不爱看。。。网上大多数的代码都是有问题的，跑不了的。。。直接在onstart里面加上下面的代码就OK了

override fun onStart() {
        super.onStart()
        val dialog = dialog as BottomSheetDialog
        if (dialog != null) {
            val bottomSheet = dialog.delegate.findViewById<View>(com.google.android.material.R.id.design_bottom_sheet)
            bottomSheet!!.getLayoutParams().height = ViewGroup.LayoutParams.WRAP_CONTENT  //自定义高度
        }
        val view = view
        view!!.post {
            val parent = view.parent as View
            val params = parent.layoutParams as CoordinatorLayout.LayoutParams
            val behavior = params.behavior
            val bottomSheetBehavior = behavior as BottomSheetBehavior<*>?
            bottomSheetBehavior!!.peekHeight = view.measuredHeight
        }
    }