Android Studio 2.3.3不会从JAR加载类文件

Question

I've copied a jar file into my project's libs folder. Usually it will show me all of the files contained therein. For this one JAR file, it won't display the class file embedded inside, but does display a manifest file.

Let's say the jar is custom-unity-activity.jar and the directory structure is com\\custom\\activity\\custom-unity-activity.class. As far as Android Studio gets is "com.custom" and then goes no further. The compiler also can't resolve symbols defined in the class file, so it definitely isn't reading it in.

I know this jar file is valid, because it has been used successfully under a different build environment.

Answer 1

It's really hard to import Unity's project into an existing Android Project. The solution is to do it the other way around instead.

Build the Android Studio project as to jar or .arr plugin then place in your Unity project at: <ProjectName>Assets\\Plugins\\Android .

If you want to load your Android Studio project activity, you must modify the AndroidManifest.xml to let Unity know that then place it at: <ProjectName>Assets\\Plugins\\Android .

Below is what the XML should look like. It will specify the activity name to load and will also tell Unity to allow you to use input events from your Android Studio project otherwise, Unity will steal those events. The manifest below assumes that the Android Studio activity name is "MainActivity".

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
          package="com.casualcoder.plugin" android:installLocation="auto">

  <uses-sdk
    android:minSdkVersion="19"
    android:targetSdkVersion="19" />

  <supports-screens
android:smallScreens="true"
android:normalScreens="true"
android:largeScreens="true"
android:xlargeScreens="true"
android:anyDensity="true" />

  <application android:icon="@drawable/app_icon" android:label="@string/app_name">

    <activity android:name=".MainActivity"
             android:label="@string/app_name"
             android:configChanges="fontScale|keyboard|keyboardHidden|locale|mnc|mcc|navigation|orientation|screenLayout|screenSize|smallestScreenSize|uiMode|touchscreen">
      <meta-data android:name="android.app.lib_name" android:value="unity" />
      <meta-data android:name="unityplayer.ForwardNativeEventsToDalvik" android:value="true" />
      <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
      </intent-filter>
    </activity>

    <activity android:name="com.unity3d.player.UnityPlayerNativeActivity"
      android:configChanges="fontScale|keyboard|keyboardHidden|locale|mnc|mcc|navigation|orientation|screenLayout|screenSize|smallestScreenSize|uiMode|touchscreen"
android:screenOrientation="landscape">
      <meta-data android:name="android.app.lib_name" android:value="unity" />
      <meta-data android:name="unityplayer.ForwardNativeEventsToDalvik" android:value="true" />
    </activity>
      android:configChanges="fontScale|keyboard|keyboardHidden|locale|mnc|mcc|navigation|orientation|screenLayout|screenSize|smallestScreenSize|uiMode|touchscreen"
android:screenOrientation="landscape">
      <meta-data android:name="android.app.lib_name" android:value="unity" />
      <meta-data android:name="unityplayer.ForwardNativeEventsToDalvik" android:value="true" />
    </activity>

  </application>
</manifest>