KeepAliveActivity.java

package com.forfan.bigbang.component.activity;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.Gravity;
import android.view.Window;
import android.view.WindowManager;

/**
 * 在锁屏后启动activity，解锁后关闭，可以提高进程的优先级，不被杀死
 */
public class KeepAliveActivity extends AppCompatActivity {

    private ScreenBroadcastReceiver receiver;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        receiver = new ScreenBroadcastReceiver();
        IntentFilter filter = new IntentFilter();
        filter.addAction(Intent.ACTION_SCREEN_ON);
        filter.addAction(Intent.ACTION_SCREEN_OFF);
        filter.addAction(Intent.ACTION_USER_PRESENT);
        try {
            registerReceiver(receiver,filter);
        } catch (Throwable e) {
        }

        Window window = getWindow();
        //放在左上角
        window.setGravity(Gravity.START | Gravity.TOP);
        WindowManager.LayoutParams attributes = window.getAttributes();
        //宽高设计为1个像素
        attributes.width = 1;
        attributes.height = 1;
        //起始坐标
        attributes.x = 0;
        attributes.y = 0;
        window.setAttributes(attributes);
    }

    @Override
    protected void onDestroy() {
        try {
            unregisterReceiver(receiver);
        } catch (Throwable e) {
        }
        super.onDestroy();
    }

    private class ScreenBroadcastReceiver extends BroadcastReceiver {
        @Override
        public void onReceive(Context context, Intent intent) {
            String action = intent.getAction();
            if (Intent.ACTION_SCREEN_ON.equals(action)) {
            } else if (Intent.ACTION_SCREEN_OFF.equals(action)) {
            } else if (Intent.ACTION_USER_PRESENT.equals(action)) {
                finish();
            }
        }
    }
}