Android：从广播接收器获取屏幕旋转

Question

我有一个 AlarmManager，每 5 分钟执行一次 Intent Broadcast：

AlarmManager alarmManager = (AlarmManager) context.getSystemService(Context.ALARM_SERVICE);
alarmManager.setExact(AlarmManager.RTC_WAKEUP, System.currentTimeMillis() + 300000, PendingIntent.getBroadcast(context, 0, new Intent(context, Sensors.class), 0));

在BroadcastReceiver的onReceive方法中，我需要知道设备方向（0°、90°、180°、270°）：

int orientation = ((WindowManager) context.getSystemService(Context.WINDOW_SERVICE)).getDefaultDisplay().getOrientation();

一切正常。但是当我最小化或关闭应用程序时，即使设备水平放置，屏幕的旋转总是返回 0°（android 主屏幕的方向）。

我如何从 BroadcastReceiver 知道设备的旋转，而与应用或设备的状态无关？

Answer 1

我终于用加速度计解决了这个问题：

SensorManager sensorManager = (SensorManager) context.getSystemService(Context.SENSOR_SERVICE);

if (sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER) != null) {
final SensorEventListener sensorEventListener = new SensorEventListener() {
    public void onSensorChanged(SensorEvent event) {
        sensorManager.unregisterListener(this);

        int orientation;

        // Vertical
        if (Math.abs(event.values[1]) > Math.abs(event.values[0]) && Math.abs(event.values[1]) > Math.abs(event.values[2]))
            if (event.values[1] > 0)
                orientation = 0; // Head Up
            else
                orientation = 180; // Head Down

        // Horizontal
        else if (Math.abs(event.values[0]) > Math.abs(event.values[1]) && Math.abs(event.values[0]) > Math.abs(event.values[2]))
            if (event.values[0] > 0)
                orientation = 90; // Left
            else
                orientation = 270; // Right

        // Flat
        else
            orientation = 0;
    }

    public void onAccuracyChanged(Sensor sensor, int accuracy) {

    }
};

sensorManager.registerListener(sensorEventListener, sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER), SensorManager.SENSOR_DELAY_FASTEST);
}

Answer 2

This tutorial 可能对未来的搜索者有用。

要完成这项工作，首先需要创建一个继承自 BroadcastReceiver 并实现 onReceive() 方法的类。这个方法告诉BroadcastReceiver 在检测到正确的 Intent 时应该做什么。因此，目前，正在定义 BroadcastReceiver 类的子类，以便在触发 BroadcastReceiver 时必须执行的代码。在本教程的后面，您将了解如何过滤意图以检测方向变化。为简单起见，下面的代码检测设备的方向变化和角度，并在 Toast 通知中显示此信息。代码如下：

package fortyonepost.com.orientationbrec;   

import android.content.BroadcastReceiver;  
import android.content.Context;  
import android.content.Intent;  
import android.content.res.Configuration;  
import android.view.Surface;  
import android.view.WindowManager;  
import android.widget.Toast;  

public class OrientationBroadcastReceiver extends BroadcastReceiver  
{  
    //An integer that holds the value of the orientation given by the current configuration  
    private int configOrientation;  

    //A WindowManager object that will act as a handle to the window service  
    private WindowManager wm;  
    //An integer that holds the value of the orientation (in degrees) given by the window service  
    private int windowServOrientation;  

    @Override  
    public void onReceive(Context context, Intent intent)  
    {  
        //Get the orientation from the current configuration object  
        configOrientation = context.getResources().getConfiguration().orientation;  

        //Display the current orientation using a Toast notification  
        switch (configOrientation)  
        {  
            case Configuration.ORIENTATION_LANDSCAPE:  
            {  
                Toast.makeText(context, "Orientation is LANDSCAPE", Toast.LENGTH_SHORT).show();  
                break;  
            }  
            case Configuration.ORIENTATION_PORTRAIT:  
            {  
                Toast.makeText(context, "Orientation is PORTRAIT", Toast.LENGTH_SHORT).show();  
                break;  
            }  
            case Configuration.ORIENTATION_SQUARE:  
            {  
                Toast.makeText(context, "Orientation is SQUARE", Toast.LENGTH_SHORT).show();  
                break;  
            }  

            case Configuration.ORIENTATION_UNDEFINED:  
            default:  
            {  
                Toast.makeText(context, "Orientation is UNDEFINED", Toast.LENGTH_SHORT).show();  
                break;  
            }  
        }   

        //Get a handle to the Window Service  
        wm = (WindowManager)context.getSystemService(Context.WINDOW_SERVICE);  
        //Query the current orientation made available by the Window Service  
        //The getOrientation() method is deprecated. Instead, use getRotation() when targeting Android API 8 (Android 2.2 - Froyo) or above.  
        windowServOrientation =  wm.getDefaultDisplay().getOrientation();  

        //Display the current orientation using a Toast notification  
        switch (windowServOrientation)  
        {  
            case Surface.ROTATION_0:  
            {  
                Toast.makeText(context, "Rotation is 0 degrees.", Toast.LENGTH_SHORT).show();  
                break;  
            }  

            case Surface.ROTATION_90:  
            {  
                Toast.makeText(context, "Rotation is 90 degrees.", Toast.LENGTH_SHORT).show();  
                break;  
            }  

            case Surface.ROTATION_180:  
            {  
                Toast.makeText(context, "Rotation is 180 degrees.", Toast.LENGTH_SHORT).show();  
                break;  
            }  

            case Surface.ROTATION_270:  
            {  
                Toast.makeText(context, "Rotation is 270 degrees.", Toast.LENGTH_SHORT).show();  
                break;  
            }  
        }  
    }  
}

这是负责注册的 Activity 和 unregistering BroadcastReceiver。代码如下：

package fortyonepost.com.orientationbrec;  

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

public class OrientationBroadcastReceiverActivity extends Activity  
{  
    //Create and initialize an OrientationBroadcastReceiver object  
    private OrientationBroadcastReceiver orientationBR = new OrientationBroadcastReceiver();  
    //Create and initialize a new IntentFilter  
    private IntentFilter orientationIF = new IntentFilter(Intent.ACTION_CONFIGURATION_CHANGED);  

    /** Called when the activity is first created. */  
    @Override  
    public void onCreate(Bundle savedInstanceState)  
    {  
        super.onCreate(savedInstanceState);  
        setContentView(R.layout.main);  
    }  

    @Override  
    protected void onResume()  
    {  
        //Register the Orientation BroadcasReceiver  
        this.registerReceiver(orientationBR, orientationIF);  
        super.onResume();  
    }  

    @Override  
    protected void onPause()  
    {  
        //Unregister the Orientation BroadcasReceiver to avoid a BroadcastReceiver leak  
        this.unregisterReceiver(orientationBR);  
        super.onPause();  
    }  
}  

Answer 3

也许this 就是您要搜索的内容。

context.getResources().getConfiguration().orientation

this way你可以得到实时变化。