求助：SplashActivity注册注销ConnectivityReceiver后仍内存泄漏

咱们先从可能的泄漏根源入手，一步步排查解决：

1. 先排查Receiver的引用持有问题 #

如果你的ConnectivityReceiver是非静态内部类，它会默认持有外部SplashActivity的强引用。哪怕你在onDestroy里注销了接收器，只要系统广播队列还持有这个Receiver的引用，就会把Activity拽着不让GC回收。

修复方案： #

把ConnectivityReceiver改成静态内部类，如果需要调用Activity的方法，用WeakReference来弱引用Activity实例，避免强引用锁死：

public static class ConnectivityReceiver extends BroadcastReceiver {
    private WeakReference<SplashActivity> activityWeakRef;

    public ConnectivityReceiver(SplashActivity activity) {
        activityWeakRef = new WeakReference<>(activity);
    }

    @Override
    public void onReceive(Context context, Intent intent) {
        SplashActivity activity = activityWeakRef.get();
        // 先判断Activity是否存活，再执行逻辑
        if (activity != null && !activity.isFinishing() && !activity.isDestroyed()) {
            // 处理网络状态变化逻辑
        }
    }
}

2. 确认广播注册/注销的上下文一致性 #

如果你用的是动态注册registerReceiver(receiver, intentFilter)，一定要保证注册和注销用的是同一个上下文：比如注册时用SplashActivity.this，注销时也必须用这个实例，不能换成getApplicationContext()，否则系统会认为是两个不同的注册操作，导致原Receiver无法被正确注销。

另外，建议把注册/注销的时机调整到onResume/onPause，而不是onCreate/onDestroy——因为如果Activity被系统后台回收，onDestroy可能不会被执行，导致Receiver永远挂在系统里：

private ConnectivityReceiver connectivityReceiver;

@Override
protected void onResume() {
    super.onResume();
    connectivityReceiver = new ConnectivityReceiver(this);
    IntentFilter filter = new IntentFilter(ConnectivityManager.CONNECTIVITY_ACTION);
    registerReceiver(connectivityReceiver, filter);
}

@Override
protected void onPause() {
    super.onPause();
    if (connectivityReceiver != null) {
        unregisterReceiver(connectivityReceiver);
        connectivityReceiver = null; // 主动置空，切断引用
    }
}

3. 查看LeakCanary的引用链细节 #

LeakCanary的泄漏报告里会清晰展示引用链，你可以顺着链条找根源：比如是不是ConnectivityManager还持有Receiver的引用？或者有没有其他静态变量意外持有了Activity的实例？

举个例子，如果报告显示ConnectivityManager -> ConnectivityReceiver -> SplashActivity，那基本就是Receiver没被正确注销，或者Receiver持有Activity强引用导致的。

4. 更省心的替代方案：用Lifecycle组件管理广播 #

如果你的项目用了AndroidX，推荐用LifecycleObserver来自动管理广播的注册和注销，完全不用手动处理时机问题：

public class ConnectivityLifecycleObserver implements LifecycleObserver {
    private final Context appContext;
    private ConnectivityReceiver receiver;

    public ConnectivityLifecycleObserver(Context context) {
        this.appContext = context.getApplicationContext();
        receiver = new ConnectivityReceiver();
    }

    @OnLifecycleEvent(Lifecycle.Event.ON_RESUME)
    void registerReceiver() {
        IntentFilter filter = new IntentFilter(ConnectivityManager.CONNECTIVITY_ACTION);
        appContext.registerReceiver(receiver, filter);
    }

    @OnLifecycleEvent(Lifecycle.Event.ON_PAUSE)
    void unregisterReceiver() {
        appContext.unregisterReceiver(receiver);
    }
}

然后在SplashActivity里添加观察者：

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    getLifecycle().addObserver(new ConnectivityLifecycleObserver(this));
}

这样Lifecycle会自动在Activity进入前台时注册广播，退到后台时注销，从根源避免泄漏问题。

内容的提问来源于stack exchange，提问作者nikhil n