使用反射从隐藏的AOSP类获取私有字段

Question

val activityViewClass = Class.forName("android.app.ActivityView")
val activityView = activityViewClass.getConstructor(Context::class.java).newInstance(this)

如果调用ActivityView::Class.java.DeclaredFields，将得到一个空列表。

我尝试在Java中，在Kotlin中使用kotlin-reflect库，但没有成功。

我还尝试了https://github.com/ronmamo/reflections库进行反射，我得到了同样的结果。

/** Callback that notifies when the container is ready or destroyed. */
    public abstract static class StateCallback {
        /**
         * Called when the container is ready for launching activities. Calling
         * {@link #startActivity(Intent)} prior to this callback will result in an
         * {@link IllegalStateException}.
         *
         * @see #startActivity(Intent)
         */
        public abstract void onActivityViewReady(ActivityView view);
        /**
         * Called when the container can no longer launch activities. Calling
         * {@link #startActivity(Intent)} after this callback will result in an
         * {@link IllegalStateException}.
         *
         * @see #startActivity(Intent)
         */
        public abstract void onActivityViewDestroyed(ActivityView view);
        /**
         * Called when a task is moved to the front of the stack inside the container.
         * This is a filtered version of {@link TaskStackListener}
         */
        public void onTaskMovedToFront(ActivityManager.StackInfo stackInfo) { }
    }

你知道如何访问那个私有字段或者如何使用反射扩展一个隐藏的抽象类吗？

Answer 1

系统应用程序无需做任何事情就可以访问隐藏类。如果可以访问ActivityView，还可以访问StateCallback。

您应该定义状态

private StateCallback mStateCallback = new StateCallback() {
            @Override
            public void onActivityViewReady(ActivityView view) {
                Log.v(LOG_TAG, "onActivityViewReady");
            }

            @Override
            public void onActivityViewDestroyed(ActivityView view) {
                Log.v(LOG_TAG, "onActivityViewDestroyed");
            }

            @Override
            public void onTaskMovedToFront(ActivityManager.StackInfo stackInfo) {
                Log.v(LOG_TAG, "onTaskMovedToFront");
            }
        };

然后这样设置

    mActivityView = findViewById(R.id.activity_view);
    mActivityView.setCallback(mStateCallback);