屏幕开/关的广播接收器不起作用

Question

我正在尝试使用 BroadcastReceiver 但它不起作用，请帮我解决这个问题。 MyReceiver.java

package com.example.broadcast_receiver;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.util.Log;

public class MyReceiver extends BroadcastReceiver {

    @Override
    public void onReceive(Context context, Intent intent) {
        // TODO Auto-generated method stub
        Log.i("[BroadcastReceiver]", "MyReceiver");

        if(intent.getAction().equals(Intent.ACTION_SCREEN_ON)){
            Log.i("[BroadcastReceiver]", "Screen ON");
        }
        else if(intent.getAction().equals(Intent.ACTION_SCREEN_OFF)){
            Log.i("[BroadcastReceiver]", "Screen OFF");
        }
    }
}

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.broadcast_receiver"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="9"
        android:targetSdkVersion="16" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >

        <receiver android:name=".MyReceiver" 
            android:enabled="true"
            android:exported="false">
            <intent-filter>
                <action android:name="android.intent.action.SCREEN_ON"/>
                <action android:name="android.intent.action.SCREEN_OFF"/>
            </intent-filter>
        </receiver>

        <activity
            android:name="com.example.broadcast_receiver.MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

BroadcastReceiver 不工作，也没有生成任何日志，请帮我解决这个问题。

Answer 1

嘿尝试使用广播的动态调用，我试过这个它会很好地工作......

public class MainActivity extends Activity {

    //Create broadcast object
    BroadcastReceiver mybroadcast = new BroadcastReceiver() {    
        //When Event is published, onReceive method is called
        @Override
        public void onReceive(Context context, Intent intent) {
            // TODO Auto-generated method stub
            Log.i("[BroadcastReceiver]", "MyReceiver");

            if (intent.getAction().equals(Intent.ACTION_SCREEN_ON)) {
                Log.i("[BroadcastReceiver]", "Screen ON");
            }
            else if (intent.getAction().equals(Intent.ACTION_SCREEN_OFF)) {
                Log.i("[BroadcastReceiver]", "Screen OFF");
            }

        }
    };

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

        registerReceiver(mybroadcast, new IntentFilter(Intent.ACTION_SCREEN_ON));
        registerReceiver(mybroadcast, new IntentFilter(Intent.ACTION_SCREEN_OFF));
    }
}

Answer 2

如果您希望系统调用此接收器，则需要将其导出。您设置了exported =“false”，将其更改为true 或完全删除exported，这将开始工作。通常这是不安全的，但由于 SCREEN_ON 和 SCREEN_OFF 都是受保护的广播，并且您验证操作，只有更受信任的系统代码才能将它们发送给您，所以它非常安全。

遗憾的是，这在这种情况下不起作用，因为意图广播具有以下标志： Intent.FLAG_RECEIVER_REGISTERED_ONLY | Intent.FLAG_RECEIVER_FOREGROUND

Answer 3

您可以尝试获取电池值吗：

public class Broadcast extends Activity {
    //Create broadcast object
    BroadcastReceiver mybroadcast = new BroadcastReceiver() {

        //When Event is published, onReceive method is called
        @Override
        public void onReceive(Context context, Intent intent) {
            //Get battery percentage
            int batterylevel = intent.getIntExtra("level", 0);    
            //get progressbar
            ProgressBar myprogressbar = (ProgressBar) findViewById(R.id.progressbar);
            myprogressbar.setProgress(batterylevel);
            TextView tv = (TextView) findViewById(R.id.textfield);
            //Set TextView with text
            tv.setText("Battery Level: " + Integer.toString(batterylevel) + "%");
        }
    });

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_broadcast);   
        registerReceiver(mybroadcast, new IntentFilter(Intent.ACTION_BATTERY_CHANGED));
    }
}