阴影无法进入自定义视图

Question

我已经为EditText创建了Shape。而且，我要做的只是为它蒙上阴影。我尝试了一切，但阴影没有来临。

以下是我的形状

我尝试设置android:elevation="6dp"和android:translationZ="2dp"，但没有成功。

这是我的xml代码：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@color/colorGreen"
    tools:context=".MainActivity">

    <RelativeLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="20dp"
        android:layout_marginTop="20dp"
        android:clipToPadding="false"
        android:elevation="6dp"
        android:gravity="center"
        android:translationZ="2dp">

        <EditText
            android:id="@+id/left"
            android:layout_width="130dp"
            android:layout_height="wrap_content"
            android:background="@android:color/transparent"
            android:elevation="20dp"
            android:paddingStart="10dp"
            android:paddingTop="5dp"
            android:paddingEnd="10dp" />

        <com.brar.shape.LeftShape
            android:id="@+id/myshape"
            android:layout_width="130dp"
            android:layout_height="60dp"
            android:elevation="2dp"
            app:fillColor="#ffffff" />

    </RelativeLayout>


</RelativeLayout>

我的自定义视图代码如下：

import android.content.Context
import android.content.res.TypedArray
import android.graphics.*
import android.util.AttributeSet
import android.util.Log
import android.view.View


class LeftShape @JvmOverloads constructor(
    context: Context,
    attrs: AttributeSet? = null,
    defStyleAttr: Int = 0
) : View(context, attrs, defStyleAttr) {

    private val attribute = attrs

    private val paintArc: Paint = Paint()
    private val paintHorizontalLine: Paint = Paint()
    private var color: Int
    val path = Path();

    init {
        val ta: TypedArray =
            context.obtainStyledAttributes(attribute, R.styleable.LeftShapeView, 0, 0)
        color = Color.WHITE;
        try {
            color = ta.getColor(com.brar.shape.R.styleable.LeftShapeView_fillColor, Color.WHITE);
        } finally {
            ta.recycle();
        }

        paintArc.isAntiAlias = true
        paintArc.color = color
        paintArc.style = Paint.Style.FILL
        paintHorizontalLine.isAntiAlias = true
        paintHorizontalLine.color = color
        paintHorizontalLine.style = Paint.Style.STROKE
        paintHorizontalLine.strokeWidth = 8f

    }


    override fun onDraw(canvas: Canvas?) {
        super.onDraw(canvas)

        var width = canvas!!.width
        var height = canvas!!.height

        if (width == 0) width = (height * 2)

        val radius = height / 2

        val circleTop = 0;
        val circleLeft = 0;
        val circleBottom = radius
        val circleRight = radius
        val fromAngle = 90f;
        val sweepAngle = 180f;

        val rectF = RectF(
            circleLeft.toFloat(),
            circleTop.toFloat(),
            circleRight.toFloat(),
            circleBottom.toFloat()
        )
        canvas!!.drawArc(rectF, fromAngle, sweepAngle, false, paintArc)

        //Draw Rectangle and Right angle triangle

        val rectangleTopEnd = width;
        val topTopStart = radius / 2;

        var lastWidthOfRectangle = width;
        Log.d("AK", "Rectangle Width: $width")
        if (width > 0) {
            val widthToReduce = width.toFloat() * 0.10
            Log.d("AK", "Rectangle widthToReduce: ${widthToReduce}")
            if (width > widthToReduce) {
                lastWidthOfRectangle = (width - widthToReduce).toInt()
                Log.d("AK", "Rectangle lastWidthOfRectangle: ${lastWidthOfRectangle}")

            } else {
                Log.d("AK", "What happened")
            }
        }

        path.moveTo(rectangleTopEnd.toFloat(), 0f)
        path.lineTo(rectangleTopEnd.toFloat(), 0f)
        path.lineTo(topTopStart.toFloat(), 0f)
        path.lineTo(topTopStart.toFloat(), radius.toFloat())
        path.lineTo(lastWidthOfRectangle.toFloat(), radius.toFloat())
        path.lineTo(width.toFloat(), 0f)

        canvas.drawPath(path, paintArc);

    }
}