android - onReceive 从未调用过

Question

我有以下代码我想检测手机屏幕但是永远不会调用函数 onReceive谁能给我一个解决方案。请帮忙。如果有人有任何其他工作代码，请提供帮助。谢谢

package com.pack;

import android.app.Activity;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;

public class Screen extends Activity {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        IntentFilter filter = new IntentFilter();
        filter.addAction(Intent.ACTION_SCREEN_OFF);
     Context con = this;
        this.registerReceiver(new BroadcastReceiver() {

              @Override
              public void onReceive(Context context, Intent intent) {
               System.out.println("Screen off...................");
              }
            }, new IntentFilter(Intent.ACTION_SCREEN_OFF));
    }

}

Answer 1

您的代码对我有用。我修改了代码，使其更易于阅读并添加了一些系统输出，但它的工作方式与您编写的方式相同:

public class Test extends Activity {

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    IntentFilter filter = new IntentFilter(Intent.ACTION_SCREEN_OFF);
    registerReceiver(new BroadcastReceiver() {

        @Override
        public void onReceive(Context context, Intent intent) {
            System.out.println("Screen off...................");
        }

    }, filter);
}

@Override
protected void onResume() {
    super.onResume();
    System.out.println("onResume()");
}

@Override
protected void onDestroy() {
    super.onDestroy();
    System.out.println("onDestroy()");
}

@Override
protected void onPause() {
    super.onPause();
    System.out.println("onPause()");
}

如果我这样做(启动 Activity 、关闭屏幕、打开屏幕、按返回按钮)，它会打印以下内容:

onResume()
onPause()
Screen off...................
onResume()
onPause()
onDestroy()

在此之后， Activity 被销毁，因此不会显示任何事件。也许您想改为在 AndroidManifest 中注册 BroadcastReceiver。