我创建了一个活动透明，它的中心布局是不透明的。我想要的是之前的活动（可以看到）应该是模糊的。我试过不透明，但没用。
我想做一个透明的布局 parentRelative 模糊。
透明性.xml

<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:id="@+id/parentRelative"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@android:color/transparent"
    android:layout_margin="30dp"
    tools:context=".TransparentActivity">

    <RelativeLayout
        android:id="@+id/secondParentRelative"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_centerInParent="true">

        ...

    </RelativeLayout>

</RelativeLayout>

透明性.java

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    RelativeLayout relativeLayout = findViewById(R.id.parentRelative);
    relativeLayout.setBackground(new BitmapDrawable(getResources(),
                            blur(TransparentActivity.this, captureScreenShot(relativeLayout))));
}

public static Bitmap captureScreenShot(View view) {
        Bitmap bitmap = Bitmap.createBitmap(view.getWidth(), view.getHeight(), Bitmap.Config.ARGB_4444);
        Canvas canvas = new Canvas(bitmap);
        Drawable backgroundDrawable = view.getBackground();
        if (backgroundDrawable != null) {
            backgroundDrawable.draw(canvas);
        } else {
            canvas.drawColor(Color.parseColor("#80000000"));
        }
        view.draw(canvas);
        return bitmap;
}

public static Bitmap blur(Context context, Bitmap image) {
    float BITMAP_SCALE = 0.4f;
    float BLUR_RADIUS = 23f;

    int width = Math.round(image.getWidth() * BITMAP_SCALE);
    int height = Math.round(image.getHeight() * BITMAP_SCALE);
    Bitmap inputBitmap = Bitmap.createScaledBitmap(image, width, height, false);
    Bitmap outputBitmap = Bitmap.createBitmap(inputBitmap);
    RenderScript rs = RenderScript.create(context);
    ScriptIntrinsicBlur theIntrinsic = ScriptIntrinsicBlur.create(rs, Element.U8_4(rs));
    Allocation tmpIn = Allocation.createFromBitmap(rs, inputBitmap);
    Allocation tmpOut = Allocation.createFromBitmap(rs, outputBitmap);
    theIntrinsic.setRadius(BLUR_RADIUS);
    theIntrinsic.setInput(tmpIn);
    theIntrinsic.forEach(tmpOut);
    tmpOut.copyTo(outputBitmap);

    return outputBitmap;
}

这个 blur 以及 captureScreenShot 是我从其他人那里得到的答案。但它不起作用。
我想使透明的布局模糊。
有人能告诉我我错过了什么吗？