Unity安卓应用重启代码在Android 10中失效，求解决方案

The issue with your original code boils down to Android 10 (API 29) and later's strict restrictions on background activity starts. When you use AlarmManager to trigger a PendingIntent after killing your app's process, the system blocks the launch—your app is no longer in the foreground, so it doesn’t meet the exception criteria for background activity starts.

Here’s a reliable workaround that avoids this restriction by launching the new activity instance while your app is still in a foreground state:

using UnityEngine;
using System;

public class AndroidAppRestarter : MonoBehaviour
{
    public void TriggerAppRestart()
    {
        try
        {
            // Access the current Unity activity
            using (AndroidJavaClass unityPlayer = new AndroidJavaClass("com.unity3d.player.UnityPlayer"))
            using (AndroidJavaObject currentActivity = unityPlayer.GetStatic<AndroidJavaObject>("currentActivity"))
            {
                // Fetch package manager and app launch intent
                AndroidJavaObject packageManager = currentActivity.Call<AndroidJavaObject>("getPackageManager");
                string appPackage = Application.identifier;
                AndroidJavaObject launchIntent = packageManager.Call<AndroidJavaObject>("getLaunchIntentForPackage", appPackage);

                // Set critical flags for a clean restart
                // FLAG_ACTIVITY_CLEAR_TOP: Wipes existing activity stack to start fresh
                // FLAG_ACTIVITY_NEW_TASK: Ensures the activity launches in a valid context
                // FLAG_ACTIVITY_NO_ANIMATION: Optional, removes transition flicker
                int intentFlags = 0x04000000 | 0x10000000 | 0x00010000; // Corresponding flag values
                launchIntent.Call<AndroidJavaObject>("setFlags", intentFlags);

                // Launch the new activity BEFORE killing the current process
                currentActivity.Call("startActivity", launchIntent);

                // Terminate the current process to complete the restart
                using (AndroidJavaClass processClass = new AndroidJavaClass("android.os.Process"))
                {
                    int currentPid = processClass.CallStatic<int>("myPid");
                    processClass.CallStatic("killProcess", currentPid);
                }
            }
        }
        catch (Exception e)
        {
            Debug.LogError($"Restart failed: {e.Message}");
        }
    }
}

Key Fixes & Explanations: #

• Avoid Background Launch: By starting the new activity while the current activity is still active (foreground state), we bypass Android’s background launch block.
• Intent Flags:
  • FLAG_ACTIVITY_CLEAR_TOP ensures your app starts fresh by clearing any existing activity stack.
  • FLAG_ACTIVITY_NEW_TASK guarantees the activity launches in a valid context when restarting.
• No AlarmManager Dependency: We don’t need delayed triggers—launching immediately before killing the process works reliably without system interference.

Quick Notes: #

• Ensure your main activity in AndroidManifest.xml uses a standard launch mode (default singleTop or standard works perfectly here).
• Test on a physical Android 10+ device—emulators can have inconsistent process management behavior.
• If you need a short delay (e.g., to save app state), use Invoke(nameof(TriggerAppRestart), 1f) instead of AlarmManager.

内容的提问来源于stack exchange，提问作者user2900584