constraintLayout 作为DialogFragment 跟布局展示失效的问题

先来一个对比图

想要这个样子的

结果 是这个样子的

布局我是这样写的

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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">

   <ImageView
       android:id="@+id/iv_ad_show"
       android:layout_width="0dp"
       android:layout_height="0dp"
       android:scaleType="centerCrop"
       app:layout_constraintBottom_toBottomOf="parent"
       app:layout_constraintHeight_percent="0.5"
       app:layout_constraintLeft_toLeftOf="parent"
       app:layout_constraintRight_toRightOf="parent"
       app:layout_constraintTop_toTopOf="parent"
       app:layout_constraintVertical_bias="0.4"
       app:layout_constraintWidth_percent="0.65" />

   <ImageView
       android:id="@+id/cancel"
       android:layout_width="0dp"
       android:layout_height="0dp"
       android:src="@mipmap/ic_launcher"
       app:layout_constraintBottom_toBottomOf="parent"
       app:layout_constraintDimensionRatio="1"
       app:layout_constraintLeft_toLeftOf="@id/iv_ad_show"
       app:layout_constraintRight_toRightOf="@id/iv_ad_show"
       app:layout_constraintTop_toBottomOf="@id/iv_ad_show"
       app:layout_constraintVertical_bias="0.2"
       app:layout_constraintWidth_percent="0.1" />

</androidx.constraintlayout.widget.ConstraintLayout>

最开始 DialogFragment 是这样写的：

package com.rth.commonlibrary.view.dialog

import android.app.Dialog
import android.graphics.Color
import android.graphics.drawable.ColorDrawable
import android.os.Bundle
import android.support.v4.app.DialogFragment
import android.support.v4.app.Fragment
import android.support.v7.app.AppCompatActivity
import android.view.*
import com.bumptech.glide.Glide
import com.rth.commonlibrary.R
import kotlinx.android.synthetic.main.layout_advert_dialog.view.*


/**
 * 首页弹出广告显示
 * @author WangHongBin ^_^
 * @date 2020/5/11 16:14
 **/
class AdvertDialogFragment constructor() : DialogFragment() {
    

    internal lateinit var dialog: Dialog

    private var callBack: (() -> Unit)? = null

    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
    
        val viewDialog: View = inflater.inflate(R.layout.layout_advert_dialog, container, false)
        dialog = getDialog()
        dialog.window.requestFeature(Window.FEATURE_NO_TITLE)
        dialog.window.setBackgroundDrawable(ColorDrawable(Color.TRANSPARENT))
        dialog.setCancelable(false)
        dialog.setCanceledOnTouchOutside(false)


        val adUrl: String = arguments!!["ad"] as String

        Glide.with(activity!!).load(adUrl).into(viewDialog.iv_ad_show)

        viewDialog.iv_ad_show.setOnClickListener {
    
            dismiss()
            callBack!!()
        }

        viewDialog.cancel.setOnClickListener {
    
            dismiss()
        }

        return viewDialog
    }

    /**
     * 点击事件回调
     */
    fun setOnClickListener(callback: () -> Unit) {
    
        this.callBack = callback
    }
    
    companion object {
    
        fun newInstance(context: AppCompatActivity, url: String): AdvertDialogFragment? {
    
            val tag = AdvertDialogFragment::class.java.name
            var fragment = context.supportFragmentManager.findFragmentByTag(tag)
            return if (fragment == null) {
    
                fragment = Fragment.instantiate(context, tag)
                val bundle = Bundle()
                bundle.putString("ad", url)
                fragment.arguments = bundle
                fragment as AdvertDialogFragment
            } else {
    
                val bundle = Bundle()
                bundle.putString("ad", url)
                fragment.arguments = bundle
                fragment as AdvertDialogFragment
            }
        }
    }
}

本来我觉的没啥问题呢，但是跑起来发现 弹窗不显示，只是有透明的感觉。当时蒙蔽了。
后来细想，应该是宽高的问题。所以后来又重新计算了宽高，加入这样的代码：

	override fun onStart() {
    
        super.onStart()
        //重新计算视图宽高  充满屏幕
        val win = getDialog().window
        // 一定要设置Background，如果不设置，window属性设置无效
        win.setBackgroundDrawable(ColorDrawable(Color.TRANSPARENT))
        win.attributes.apply {
    
            gravity = Gravity.CENTER
            width = ViewGroup.LayoutParams.MATCH_PARENT
            height = ViewGroup.LayoutParams.MATCH_PARENT
        }.let {
    
            win.attributes = it
        }
    }

这样重新计算宽高，让整体视图充满屏幕，然后constraintlayout再按宽高比例计算，就可以正常显示了

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不足之处，欢迎大佬指教！！