6

我创建了一个简单的广播接收器,它工作得非常好,除了如果我打开/关闭飞行模式,使用 onReceive 方法接收广播消息需要将近 2 分钟。另一件事是,如果我们启动应用程序,然后如果我更改飞行模式(开/关),这会导致问题,那么接收消息需要太长时间。

如果在启动应用程序之前有模式更改,它不会影响在 onReceive 方法中接收消息的时间。

源代码如下。

AndroidManifest.xml

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

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="18" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.example.broadcastreceiver.BroadcastReceiverActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

       <receiver android:name="MyBroadcastReceiver" >
            <intent-filter>
                <action android:name="test.intent.action.QR_CODE_RECEIVER" />
            </intent-filter>
        </receiver>
    </application>

</manifest>

BroadcastReceiverActivity.java

public class BroadcastReceiverActivity extends Activity {

    public static String qrCodeReceiver = "test.intent.action.QR_CODE_RECEIVER";

    @Override
    protected void onCreate(Bundle saveInstanceState){
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        Button broadcastBtn = (Button) findViewById(R.id.broadcastBtn);
        broadcastBtn.setOnClickListener(new View.onClickListener(){
            public void onClick(View v){
                //TODO
                Intent intent = new Intent();
                intent.putExtra("message","Testing");
                intent.setAction(qrCodeReceiver);
                sendBroadcast(intent);
                Log.d("Test","sendBroadcasting the message ::");
            }
        });
    }
}

MyBroadcastReceiver.java

public class MyBroadcastReceiver extends BroadcastReceiver {

    @Override
    public void onReceive(Context context, Intent intent) {
        //TODO
        Toast.makeText(context, "on receive.",Toast.LENGTH_LONG).show();
        Bundle extras = intent.getExtras();
        String state = extras.getString("message");
        Log.d("Test", "Inside MyBroadcastReceiver onReceive() state :: "+ state);
        Toast.makeText(context, state,Toast.LENGTH_LONG).show();
    }
}

主要的.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".BroadcastReceiverActivity" >

<TextView
    android:id="@+id/textView1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/hello_world" />

<Button
    android:id="@+id/broadcastBtn"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_below="@+id/textView1"
    android:layout_centerHorizontal="true"
    android:layout_marginTop="48dp"
    android:text="Send The BroadCast Message" />

</RelativeLayout>

先感谢您。

4

1 回答 1

13

在 Android 系统中,广播是在内部处理的。

有时,由于系统加载/重启/高运行时间,广播接收器有时间接收一些意图

解决方法是,将标志 FLAG_RECEIVER_FOREGROUND 添加到意图发送广播

intent.addFlags(Intent.FLAG_RECEIVER_FOREGROUND);

在问题场景中,这将比以前大大加快广播传输速度

于 2015-03-19T12:55:27.463 回答