How to install Android apk from code in unity

Question

I found snippet for Java. How can I write such a code in C# Unity?

Intent intent = new Intent(Intent.ACTION_VIEW);
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
intent.setDataAndType(Uri.fromFile(new File("link to downloaded file")),"application/vnd.android.package-archive");
startActivity(intent);

Answer 1

You can build a jar/aar plugin and call it from C#. That's more easier to do.

Another solution is to use AndroidJavaObject and AndroidJavaClass to do this directly without a plugin. Doing it with AndroidJavaObject and AndroidJavaClass requires lots of testing to get it right. Below is what I use to do that. It downloads an APK then installs it.

First of all create a UI text called "TextDebug" so it you will see what's going on during the download/install. If you don't do this you must comment out or remove all the GameObject.Find("TextDebug").GetComponent<Text>().text... line of code.

void Start()
{
    StartCoroutine(downLoadFromServer());
}

IEnumerator downLoadFromServer()
{
    string url = "http://apkdl.androidapp.baidu.com/public/uploads/store_2/f/f/a/ffaca37aaaa481003d74725273c98122.apk?xcode=854e44a4b7e568a02e713d7b0af430a9136d9c32afca4339&filename=unity-remote-4.apk";


    string savePath = Path.Combine(Application.persistentDataPath, "data");
    savePath = Path.Combine(savePath, "AntiOvr.apk");

    Dictionary<string, string> header = new Dictionary<string, string>();
    string userAgent = "Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/55.0.2883.87 Safari/537.36";
    header.Add("User-Agent", userAgent);
    WWW www = new WWW(url, null, header);


    while (!www.isDone)
    {
        //Must yield below/wait for a frame
        GameObject.Find("TextDebug").GetComponent<Text>().text = "Stat: " + www.progress;
        yield return null;
    }

    byte[] yourBytes = www.bytes;

    GameObject.Find("TextDebug").GetComponent<Text>().text = "Done downloading. Size: " + yourBytes.Length;


    //Create Directory if it does not exist
    if (!Directory.Exists(Path.GetDirectoryName(savePath)))
    {
        Directory.CreateDirectory(Path.GetDirectoryName(savePath));
        GameObject.Find("TextDebug").GetComponent<Text>().text = "Created Dir";
    }

    try
    {
        //Now Save it
        System.IO.File.WriteAllBytes(savePath, yourBytes);
        Debug.Log("Saved Data to: " + savePath.Replace("/", "\\"));
        GameObject.Find("TextDebug").GetComponent<Text>().text = "Saved Data";
    }
    catch (Exception e)
    {
        Debug.LogWarning("Failed To Save Data to: " + savePath.Replace("/", "\\"));
        Debug.LogWarning("Error: " + e.Message);
        GameObject.Find("TextDebug").GetComponent<Text>().text = "Error Saving Data";
    }

    //Install APK
    installApp(savePath);
}

public bool installApp(string apkPath)
{
    try
    {
        AndroidJavaClass intentObj = new AndroidJavaClass("android.content.Intent");
        string ACTION_VIEW = intentObj.GetStatic<string>("ACTION_VIEW");
        int FLAG_ACTIVITY_NEW_TASK = intentObj.GetStatic<int>("FLAG_ACTIVITY_NEW_TASK");
        AndroidJavaObject intent = new AndroidJavaObject("android.content.Intent", ACTION_VIEW);

        AndroidJavaObject fileObj = new AndroidJavaObject("java.io.File", apkPath);
        AndroidJavaClass uriObj = new AndroidJavaClass("android.net.Uri");
        AndroidJavaObject uri = uriObj.CallStatic<AndroidJavaObject>("fromFile", fileObj);

        intent.Call<AndroidJavaObject>("setDataAndType", uri, "application/vnd.android.package-archive");
        intent.Call<AndroidJavaObject>("addFlags", FLAG_ACTIVITY_NEW_TASK);
        intent.Call<AndroidJavaObject>("setClassName", "com.android.packageinstaller", "com.android.packageinstaller.PackageInstallerActivity");

        AndroidJavaClass unityPlayer = new AndroidJavaClass("com.unity3d.player.UnityPlayer");
        AndroidJavaObject currentActivity = unityPlayer.GetStatic<AndroidJavaObject>("currentActivity");
        currentActivity.Call("startActivity", intent);

        GameObject.Find("TextDebug").GetComponent<Text>().text = "Success";
        return true;
    }
    catch (System.Exception e)
    {
        GameObject.Find("TextDebug").GetComponent<Text>().text = "Error: " + e.Message;
        return false;
    }
}

---

For Android API 24 and above, this requires a different code since the API changed. The C# code below is based on the this Java answer.

//For API 24 and above
private bool installApp(string apkPath)
{
    bool success = true;
    GameObject.Find("TextDebug").GetComponent<Text>().text = "Installing App";

    try
    {
        //Get Activity then Context
        AndroidJavaClass unityPlayer = new AndroidJavaClass("com.unity3d.player.UnityPlayer");
        AndroidJavaObject currentActivity = unityPlayer.GetStatic<AndroidJavaObject>("currentActivity");
        AndroidJavaObject unityContext = currentActivity.Call<AndroidJavaObject>("getApplicationContext");

        //Get the package Name
        string packageName = unityContext.Call<string>("getPackageName");
        string authority = packageName + ".fileprovider";

        AndroidJavaClass intentObj = new AndroidJavaClass("android.content.Intent");
        string ACTION_VIEW = intentObj.GetStatic<string>("ACTION_VIEW");
        AndroidJavaObject intent = new AndroidJavaObject("android.content.Intent", ACTION_VIEW);


        int FLAG_ACTIVITY_NEW_TASK = intentObj.GetStatic<int>("FLAG_ACTIVITY_NEW_TASK");
        int FLAG_GRANT_READ_URI_PERMISSION = intentObj.GetStatic<int>("FLAG_GRANT_READ_URI_PERMISSION");

        //File fileObj = new File(String pathname);
        AndroidJavaObject fileObj = new AndroidJavaObject("java.io.File", apkPath);
        //FileProvider object that will be used to call it static function
        AndroidJavaClass fileProvider = new AndroidJavaClass("android.support.v4.content.FileProvider");
        //getUriForFile(Context context, String authority, File file)
        AndroidJavaObject uri = fileProvider.CallStatic<AndroidJavaObject>("getUriForFile", unityContext, authority, fileObj);

        intent.Call<AndroidJavaObject>("setDataAndType", uri, "application/vnd.android.package-archive");
        intent.Call<AndroidJavaObject>("addFlags", FLAG_ACTIVITY_NEW_TASK);
        intent.Call<AndroidJavaObject>("addFlags", FLAG_GRANT_READ_URI_PERMISSION);
        currentActivity.Call("startActivity", intent);

        GameObject.Find("TextDebug").GetComponent<Text>().text = "Success";
    }
    catch (System.Exception e)
    {
        GameObject.Find("TextDebug").GetComponent<Text>().text = "Error: " + e.Message;
        success = false;
    }

    return success;
}

---

EDIT:

If you get the Exception:

Attempt to invoke virtual method 'android.content.res.XmlResourceParser android.content.pm.packageItemInfo.loadXmlMetaData(android.c‌​ontent.pm.PackageMan‌​ager.java.lang.Strin‌​g)'

You have to do few things.

1.Copy "android-support-v4.jar" from your "AndroidSDK/extras/android/support/v4/android-support-v4.jar" directory to your "UnityProject/Assets/Plugins/Android" directory.

2.Create a file called "AndroidManifest.xml" in your UnityProject/Assets/Plugins/Android directory and put the code below into it.

Make sure to replace "com.company.product" with your own package name. There are 2 instances where this appeared. You must replace both of them:

These are found in package="com.company.product" and android:authorities="com.company.product.fileprovider". Don't change or remove the "fileprovider" and don't change anything else.

Here is the "AndroidManifest.xml" file:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.company.product" xmlns:tools="http://schemas.android.com/tools" android:installLocation="preferExternal" android:versionName="1.0" android:versionCode="1">
  <supports-screens android:smallScreens="true" android:normalScreens="true" android:largeScreens="true" android:xlargeScreens="true" android:anyDensity="true" />
  <application android:theme="@style/UnityThemeSelector" android:icon="@drawable/app_icon" android:label="@string/app_name" android:debuggable="true">
    <activity android:name="com.unity3d.player.UnityPlayerActivity" android:label="@string/app_name">
      <intent-filter>
        <action android:name="android.intent.action.MAIN" />
        <category android:name="android.intent.category.LAUNCHER" />
      </intent-filter>
      <meta-data android:name="unityplayer.UnityActivity" android:value="true" />
    </activity>

    <provider
          android:name="android.support.v4.content.FileProvider"
          android:authorities="com.company.product.fileprovider"
          android:exported="false"
          android:grantUriPermissions="true">
      <meta-data
          android:name="android.support.FILE_PROVIDER_PATHS"
          android:resource="@xml/provider_paths"/>
    </provider>

  </application>
  <uses-sdk android:minSdkVersion="16" android:targetSdkVersion="23" />
</manifest>

3.Create a new file called "provider_paths.xml" in your "UnityProject/Assets/Plugins/Android/res/xml" directory and put the code below in it. As you can see, you have to create a res and then an xml folder.

Make sure to replace "com.company.product" with your own package name. It only appeared once.

Here is what you should put into this "provider_paths.xml" file:

<?xml version="1.0" encoding="utf-8"?>
<paths xmlns:android="http://schemas.android.com/apk/res/android">
  <!--<external-path name="external_files" path="."/>-->
  <external-path path="Android/data/com.company.product" name="files_root" />
  <external-path path="." name="external_storage_root" />
</paths>