Android对接Unity3D，原生View与Unity3D视图的层级关系

场景

• 1.很多人在对接unity的时候，难免产品会让你添加一些原生的view到unity视图上，但是你会发现所添加的原生view并不能被看见，你甚至开始怀疑自己的代码，但是确实代码没有错，只是原生的view被unity的UnityPlayer遮挡了，至于这个UnityPlayer后面会说到。
• 2.假如原生的activity只是单纯（有些产品可能要求其他骚操作）的加载一个unity场景，但是这个场景的模型又非常大，并且unity端没有给你一个加载场景的动画，那么很残忍的结果就是这个加载unity场景的过程中会出现界面黑屏、白屏甚至花屏（华为出现过）。这个时候产品发现不对，认为应该叫unity端加一个动画，但是，很残忍的是就算加了动画，仍然会出现短暂的界面黑屏、白屏甚至花屏。那么聪明的原生就说，我加一个原生的加载动画不就ojbk了？并且通过unity端的回调来取消这个动画不就非常优雅了。然而，然而发现新加的原生动画看不到，看到的是黑屏、白屏甚至花屏。好气！

分析

1、按照官方的文档集成，在原生中显现Unity3D场景首先是创建一个Activity，然后在这个Activity中实例化一个UnityPlayer对象就可以了（详细查看官方文档），注意这里有一个细节就是在Activity中放置UnityPlayer这个对象最好是帧布局，相对布局会卡顿，因为我们都知道，在原生中渲染速度：FrameLayout>LinearLayout>RelativeLayout，亲测，当模型过大的时候，RelativeLayout的容器基本上用不了。以下是放置unity的界面代码（不是小白直接跳过）：

open abstract class UnityPlayerActivity : AppCompatActivity() {
    protected lateinit var mUnityPlayer: BaseUnityPlayer // don't change the name of this variable; referenced from native code

    //提示框
    private var loading: LoadingDialog? = null
    //白屏菊花
    private var progress: ProgressDialog? = null

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        window.setFormat(PixelFormat.RGBX_8888) // <--- This makes xperia play happy
        mUnityPlayer = BaseUnityPlayer(this)
        mUnityPlayer.requestFocus()
    }

    override fun onNewIntent(intent: Intent?) {
        super.onNewIntent(intent)
        // To support deep linking, we need to make sure that the client can get access to
        // the last sent intent. The clients access this through a JNI api that allows them
        // to get the intent set on launch. To update that after launch we have to manually
        // replace the intent with the one caught here.
        setIntent(intent)
    }

    override fun onResume() {
        super.onResume()
        mUnityPlayer.resume()
        mUnityPlayer.windowFocusChanged(true)//unity主动聚焦
    }

    override fun onPause() {
        super.onPause()
        mUnityPlayer.pause()
    }

    override fun onDestroy() {
        mUnityPlayer.quit()
        super.onDestroy()
    }

    override fun onLowMemory() {
        super.onLowMemory()
        mUnityPlayer.lowMemory()
    }

    override fun onTrimMemory(level: Int) {
        super.onTrimMemory(level)
        if (level == ComponentCallbacks2.TRIM_MEMORY_RUNNING_CRITICAL) {
            mUnityPlayer.lowMemory()
        }
    }

    override fun onConfigurationChanged(newConfig: Configuration) {
        super.onConfigurationChanged(newConfig)
        mUnityPlayer.configurationChanged(newConfig)
    }

    override fun onWindowFocusChanged(hasFocus: Boolean) {
        super.onWindowFocusChanged(hasFocus)
        mUnityPlayer.windowFocusChanged(hasFocus)
    }

    override fun dispatchKeyEvent(event: KeyEvent): Boolean {
        return if (event.action == KeyEvent.ACTION_MULTIPLE) mUnityPlayer.injectEvent(event) else super.dispatchKeyEvent(event)
    }

    override fun onKeyUp(keyCode: Int, event: KeyEvent): Boolean {
        return mUnityPlayer.injectEvent(event)
    }

    override fun onKeyDown(keyCode: Int, event: KeyEvent): Boolean {
        return mUnityPlayer.injectEvent(event)
    }

    override fun onTouchEvent(event: MotionEvent): Boolean {
        return mUnityPlayer.injectEvent(event)
    }

    /*API12*/
    override fun onGenericMotionEvent(event: MotionEvent): Boolean {
        return mUnityPlayer.injectEvent(event)
    }

    /**
     * 用于网络加载提示的弹窗
     */
    protected fun showLoading() {
        loading = loading ?: LoadingDialog()
        loading?.setCallBack(object : LoadingDialog.OnDisMissCallBack {
            override fun disMiss() {
                cancelCurrent()
            }
        })
        if (loading?.isAdded == false) {
            loading?.show(supportFragmentManager, "Loading")
        } else {
            loading?.dialog?.show()
        }
    }

    protected fun disMisLoading() {
        loading?.dismiss()
    }

    /**
     * U3D白屏界面上的静态菊花
     */
    protected fun showProgress() {
        progress = progress ?: ProgressDialog.show(this, false, null)
        if (!progress!!.isShowing) {
            progress!!.show()
        }
    }

    protected fun disMissProgress() {
        progress!!.dismiss()
    }

    abstract fun cancelCurrent()
}

xml中（笔者放置UnityPlayer的界面布局）：

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
             xmlns:InnerView="http://schemas.android.com/apk/res-auto"
             xmlns:app="http://schemas.android.com/apk/res-auto"
             xmlns:tools="http://schemas.android.com/tools"
             xmlns:CircleProgressBar="http://schemas.android.com/apk/res-auto"
             android:layout_width="match_parent"
             android:layout_height="match_parent"
             tools:context="com.cninct.rmm.mvp.view.activity.MainUnityActivity">

    <!--unity的宿主控件，顶层和该层都是用帧布局，提高绘制效率-->
    <FrameLayout
        android:id="@+id/fl_content"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

    </FrameLayout>

    <!--底部菜单栏-->
    <include
        android:id="@+id/layout_tab"
        layout="@layout/view_main_tab"
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:layout_gravity="bottom"/>
    ......

Activity中：

 override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        setContentView(R.layout.activity_unity_main)
        initView()
        ......
    }

    //首页相关控件的初始化
    private fun initView() {
        fl_content.addView(mUnityPlayer)
    ......
    }

2、在正常显示之后就可以发现，其实真正显示Unity的就是一个布局容器fl_content，而fl_content是通过addView的方式将UnityPlayer添加进容器中，所以UnityPlayer也是一个View，继续查看UnityPlayer，一下是部分代码：

public class UnityPlayer extends FrameLayout implements d {
    public static Activity currentActivity = null;
    private static boolean n;
    c a = new c(this, (byte) 0);
    i b = null;
    private boolean c = false;
    private boolean d = true;
    private l e = new l();
    private final ConcurrentLinkedQueue f = new ConcurrentLinkedQueue();
    private BroadcastReceiver g = null;
    private boolean h = false;
    private a i = new a(this, (byte) 0);
    private TelephonyManager j;
    private j k;
    private ContextWrapper l;
    private SurfaceView m;
    private boolean o;
    private Bundle p = new Bundle();
    private n q;
    private boolean r = false;
    private ProgressBar s = null;
    private Runnable t = new Runnable() {
        public final void run() {
            int p = UnityPlayer.this.nativeActivityIndicatorStyle();
            if (p >= 0) {
                if (UnityPlayer.this.s == null) {
                    UnityPlayer.this.s = new ProgressBar(UnityPlayer.this.l, null, new int[]{16842874, 16843401, 16842873, 16843400}[p]);
                    UnityPlayer.this.s.setIndeterminate(true);
                    UnityPlayer.this.s.setLayoutParams(new LayoutParams(-2, -2, 51));
                    UnityPlayer.this.addView(UnityPlayer.this.s);
                }
                UnityPlayer.this.s.setVisibility(0);
                UnityPlayer.this.bringChildToFront(UnityPlayer.this.s);
            }
        }
    };
...

以上可以发现，其实UnityPlayer就是继承的FrameLayout，并且可以猜测这个FrameLayout中有至少一个SurfaceView显示真正的模型场景等，因为普通View是没有这个能力去渲染的，只有通过SurfaceView开启线程去渲染（证据：在与Unity通信的时候，通过Unity的消息回调去更新UI会提示不能在非主线程中更新界面的提示）。所以原生View和Unity3D场景问题其实就是在这个UnityPlayer中的SurfaceView与我们的原生View发生了Z-Index上的冲突，或者说是遮挡。那么怎样把我们的原生View放在UnityPlayer上面呢？其实我们首先需要把SurfaceView的Z-Index降低。就像开发地图和多媒体播放一样，存在地图、多媒体、普通View的显示层级，我们需要将这些层级处理一下，通过SurfaceView的setZOrderOnTop方法和setZOrderMediaOverlay方法。当然如果没有多媒体不需要设置setZOrderMediaOverlay方法。

解决问题

直接贴代码了：

class BaseUnityPlayer(contextWrapper: ContextWrapper) : UnityPlayer(contextWrapper) {

    override fun addView(child: View) {
        if (child is SurfaceView) {
            child.setZOrderOnTop(false)
        }
        super.addView(child)
    }

}