应用处于隐藏状态时，我无法从服务启动 Activity

问题描述

我有两个活动：MainActivity 和 ActivityTwo。启动应用程序时，我启动服务 serviceApp，在某些事件之后应该启动 ActivityTwo。为了测试，我在 10 秒后启动了 AsyncTask，但是如果应用程序被隐藏，Activity 不会启动

即使应用程序处于隐藏状态，我如何启动 Activity？

主活动

import androidx.appcompat.app.AppCompatActivity;
import androidx.appcompat.widget.SwitchCompat;

import android.app.ActivityManager;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.view.View;
import android.widget.Toast;

import java.security.Provider;
import java.util.List;

public class MainActivity extends AppCompatActivity {
    SharedPreferences setting;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        Intent service = new Intent(this,serviceApp.class);
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        setting = getSharedPreferences("settings",MODE_PRIVATE);
        SwitchCompat switchCompat = findViewById(R.id.switchBLock);
        switchCompat.setonCheckedchangelistener((view,bool) -> {
            SharedPreferences.Editor editor =  setting.edit();
            editor.putBoolean("block",bool);
            editor.apply();
            if(bool){
                startService(service);
            }else{
                stopService(service);
            }
        });
        if(setting.getBoolean("block",false)){
            switchCompat.setChecked(true);
        }
    }
}

活动二

import android.app.ActivityManager;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.widget.Toast;

public class ActivityTwo extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_two);
    }
}

serviceApp

import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.IBinder;

public class serviceApp extends Service {
    Context context;
    public serviceApp() {
        context = this;
    }

    @Override
    public void onCreate() {
        super.onCreate();
        new Async().execute();
    }

    class Async extends AsyncTask<Void,Void,Void>{
        @Override
        protected void onPostExecute(Void aVoid) {
            super.onPostExecute(aVoid);
            Intent startMain = new Intent();
            startMain.setClass(context,ActivityTwo.class);
            startMain.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
            startActivity(startMain);
        }

        @Override
        protected Void doInBackground(Void... voids) {
            for(int i = 0; i < 2; i++) {
                try {
                    Thread.sleep(10000);
                } catch (InterruptedException e) {
                    e.printstacktrace();
                }
            }
            return null;
        }
    }

    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }
}

AndroidManifest

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

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.AppCompat.NoActionBar">
        <activity android:name="com.example.test.ActivityTwo"></activity>

        <service
            android:name=".serviceApp"/>

        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

解决方法

我找到了解决此问题的简单方法，您需要授予应用程序 SYSTEM_ALERT_WINDOW 权限

https://developer.android.com/guide/components/activities/background-starts

AndroidManifest.xml

<uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW" />

主活动

Intent myIntent = new Intent(Settings.ACTION_MANAGE_OVERLAY_PERMISSION);
        startActivity(myIntent);