[TOC]

开发环境：

• Unity 2019.3.14f1
• Android Studio 3.4.1
  • Android9.+(Q)
  • 28.0.3 Build Tools

1 Unity导出Android工程

设置场景背景透明：

背景色RGBA设置为0，0，0，0。

2 Unity场景显示为透明子视图

2.1 默认导出工程

1. 默认导出的 Android Project 包含 launcher 和 unityLibrary 两个模块：

2. 默认导出的 Android Project 启动窗口为 unityLibrary 模块中的 UnityPlayerActivity：

2.2 将导出的Unity场景作为子模块添加到其他工程中

1. 新建一个 Empty Activity 项目（包名随意命名，无需跟unityLibrary包名一致）
2. 我们将 activity_main.xml 设计成这样：

3. 导入 unityLibrary 模块到工程中
4. app和unityLibrary模块设置
   • 设置依赖 unityLibrary 的lib目录aar文件，到工程的 build.gradle:

   allprojects {
       repositories {
           google()
           jcenter()
           // here
           flatDir {
               dirs "${project(':unityLibrary').projectDir}/libs"
           }
       }
   }

   • 将 unityLibrary 设置为默认 app 模块的依赖模块，到 app 的build.gradle:

   dependencies {
       // ......
       // here
       implementation project(path: ':unityLibrary')
   }

   • 此时会出现合并AndroidManifest.xml 主题(Theme)错误，因为两个模块使用了不同的主题配置，将unityLibrary的 AndroidManifest.xml <application 中 android:theme="@style/UnityThemeSelector.Translucent" 去掉即可。
   • 同时我们需要将 unityLibrary 的默认启动 activity UnityPlayerActivity 配置注释掉：

   <application android:isGame="true">
   <activity android:name="com.unity3d.player.UnityPlayerActivity" android:theme="@style/UnityThemeSelector" android:screenOrientation="fullSensor" android:launchMode="singleTask" android:configChanges="mcc|mnc|locale|touchscreen|keyboard|keyboardHidden|navigation|orientation|screenLayout|uiMode|screenSize|smallestScreenSize|fontScale|layoutDirection|density" android:hardwareAccelerated="false">
     <!-- 注释掉 -->
     <!--<intent-filter>-->
       <!--<action android:name="android.intent.action.MAIN" />-->
       <!--<category android:name="android.intent.category.LAUNCHER" />-->
       <!--<category android:name="android.intent.category.LEANBACK_LAUNCHER" />-->
     <!--</intent-filter>-->
     <meta-data android:name="unityplayer.UnityActivity" android:value="true" />
   </activity>

   • 为了能够调用到 unityLibrary 中的jar文件，即复用另一个模块的jar，需要修改 unityLibrary 中的build.gradle：

   dependencies {
       // 将implementation修改为api
       api fileTree(dir: 'libs', include: ['*.jar'])
       implementation(name: 'UnityAds', ext:'aar')
       implementation(name: 'UnityAdsAndroidPlugin', ext:'aar')
   }

5. 显示为子视图应用实现
   • app 模块添加 butterknife 资源绑定组件，简化我们编码，即app build.gradle:

   android {
       compileSdkVersion 29
       // ButterKnife需要开启Java8哦
       // Butterknife requires Java 8.
       compileOptions {
           sourceCompatibility JavaVersion.VERSION_1_8
           targetCompatibility JavaVersion.VERSION_1_8
       }
       // ......
   }
   dependencies {
       // ......
   
       implementation project(path: ':unityLibrary')
   
       // here
       // 记得用10.2.1哦，不要用8.x，会跟AndroidX不适配
       implementation 'com.jakewharton:butterknife:10.2.1'
       annotationProcessor 'com.jakewharton:butterknife-compiler:10.2.1'
   }

   • 到res/values/strings.xml添加一个资源描述，否则后面会出现找不到资源直接甭掉：

   <resources>
       <string name="app_name">xxx</string>
       <!-- here -->
       <string name="game_view_content_description">Game view</string>
   </resources>

   • 到 app 模块 MainActivity.java 中添加应用代码，注意onResume和onConfigurationChanged要重载：

   public class MainActivity extends AppCompatActivity {
       public final static String TAG = "MainActivity";
   
       @BindView(R.id.textView) TextView tv_test;
   
       private Unbinder mUnbinder;
       private UnityPlayer mUnityPlayer;
       private View mPlayerView;
       private LinearLayout mPlayerLayout;
       LinearLayout.LayoutParams mPlayerLayoutParams;
   
       @Override
       protected void onCreate(Bundle savedInstanceState) {
           super.onCreate(savedInstanceState);
           setContentView(R.layout.activity_main);
           mUnbinder = ButterKnife.bind(this);
   
           // Create the UnityPlayer
           mUnityPlayer = new UnityPlayer(this);
   
           // Transparent background
           if (mUnityPlayer.getChildCount() > 0 && mUnityPlayer.getChildAt(0) instanceof SurfaceView) {
               SurfaceView surfaceView = ((SurfaceView) mUnityPlayer.getChildAt(0));
               surfaceView.setZOrderOnTop(true);
               surfaceView.getHolder().setFormat(PixelFormat.TRANSLUCENT);
           }
   
           mPlayerView = mUnityPlayer.getView();
   
           // Add the Unity view SLIGHTY MODIFIED
           mPlayerLayout = (LinearLayout)findViewById(R.id.player_linear_layout);
           mPlayerLayoutParams = (LinearLayout.LayoutParams) mPlayerLayout.getLayoutParams();
   
           mPlayerLayout.addView(mPlayerView);
           mUnityPlayer.requestFocus();
       }
   
       @OnClick({R.id.player, R.id.launcher})
       public void onClick(View view) {
           switch (view.getId()) {
               case R.id.player:
                   tv_test.setText("Player");
                   UnityPlayer.UnitySendMessage("Player", "Jump", "");
                   break;
               case R.id.launcher:
                   tv_test.setText("Launcher");
                   UnityPlayer.UnitySendMessage("Launcher", "CreateBallPrefab", "");
                   break;
               default:
                   break;
           }
       }
   
       @Override
       protected void onDestroy() {
           super.onDestroy();
           if (mUnbinder != null) {
               mUnbinder.unbind();
           }
       }
   
       // Pause Unity
       @Override protected void onPause()
       {
           super.onPause();
           mUnityPlayer.pause();
       }
   
       // Resume Unity
       @Override protected void onResume()
       {
           super.onResume();
           // step1
           mUnityPlayer.resume();
       }
   
       // Low Memory Unity
       @Override public void onLowMemory()
       {
           super.onLowMemory();
           mUnityPlayer.lowMemory();
       }
   
       // Trim Memory Unity
       @Override public void onTrimMemory(int level)
       {
           super.onTrimMemory(level);
           if (level == TRIM_MEMORY_RUNNING_CRITICAL)
           {
               mUnityPlayer.lowMemory();
           }
       }
   
       // This ensures the layout will be correct.
       @Override public void onConfigurationChanged(Configuration newConfig)
       {
           super.onConfigurationChanged(newConfig);
           // step2
           mUnityPlayer.configurationChanged(newConfig);
       }
   
       // Notify Unity of the focus change.
       @Override public void onWindowFocusChanged(boolean hasFocus)
       {
           super.onWindowFocusChanged(hasFocus);
           mUnityPlayer.windowFocusChanged(hasFocus);
       }
   
       // For some reason the multiple keyevent type is not supported by the ndk.
       // Force event injection by overriding dispatchKeyEvent().
       @Override public boolean dispatchKeyEvent(KeyEvent event)
       {
           if (event.getAction() == KeyEvent.ACTION_MULTIPLE)
               return mUnityPlayer.injectEvent(event);
           return super.dispatchKeyEvent(event);
       }
   
       // Pass any events not handled by (unfocused) views straight to UnityPlayer
       @Override public boolean onKeyUp(int keyCode, KeyEvent event)     { return mUnityPlayer.injectEvent(event); }
       @Override public boolean onKeyDown(int keyCode, KeyEvent event)   { return mUnityPlayer.injectEvent(event); }
       @Override public boolean onTouchEvent(MotionEvent event)          { return mUnityPlayer.injectEvent(event); }
       /*API12*/ public boolean onGenericMotionEvent(MotionEvent event)  { return mUnityPlayer.injectEvent(event); }
   }

6. 最后结果

3 代码分析

我们在Unity工程中的Game Object 脚本中加了两个自己定义的成员函数：

public class Launcher : MonoBehaviour
{
    public GameObject ballPrefab;
    // Use this for initialization
    void Start() { // ...... }

    // Update is called once per frame
    void Update() { // ...... }

    // 自定义成员函数：创建小球
    void CreateBallPrefab()
    {
        Instantiate(this.ballPrefab);
    }
}

public class Player : MonoBehaviour
{
    protected float jump_speed = 5.0f;

    // Start is called before the first frame update
    void Start() { // ...... }

    // Update is called once per frame
    void Update() { // ...... }

    // 自定义成员函数
    void Jump()
    {
        this.GetComponent<Rigidbody>().velocity = Vector3.up * this.jump_speed;
    }
}

导出Android Project后，可以通过下面方式调用：

UnityPlayer.UnitySendMessage("GameObjectName", "MethodName", "parameter to send");

我们Android工程中通过使用两个按钮触发点击事件调用下面两个动作，从而操作Unity场景中的物体：

UnityPlayer.UnitySendMessage("Player", "Jump", "");
UnityPlayer.UnitySendMessage("Launcher", "CreateBallPrefab", "");

4 Github代码

https://github.com/yicm

5 参考链接

• https://forum.unity.com/threads/using-unity-android-in-a-sub-view.98315/
• https://forum.unity.com/threads/unity3d-export-to-android-with-transparent-background.512129/
• https://blog.csdn.net/s15100007883/article/details/103414879
• https://stackoverflow.com/questions/5391089/how-to-make-surfaceview-transparent
• https://www.cnblogs.com/OctoptusLian/p/8418534.html
• https://www.cnblogs.com/OctoptusLian/p/8529313.html