屏幕打开时开始 activity

Question

我为adnroid设计了一个锁屏。当用户按下电源按钮解锁时，我正在尝试使用广播接收器启动锁屏 activity。

public class Receiver extends BroadcastReceiver {

@Override
public void onReceive(Context context, Intent intent) {

    if(intent.getAction().equals(Intent.ACTION_SCREEN_ON)){
        Log.w("BAM", "Screen went on");
    }

    else if(intent.getAction().equals(Intent.ACTION_SCREEN_OFF)){
        Log.w("BAM","Screen went off");
    }
}

}

android 清单：`

<uses-sdk
    android:minSdkVersion="7"
    android:targetSdkVersion="21" />

<application
    android:allowBackup="true"
    android:icon="@drawable/ic_launcher"
    android:label="@string/app_name"
    android:theme="@style/AppTheme" >
    <activity
        android:name=".MyLockScreenActivity"
        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="MyAdminReceiver"
        android:permission="android.permission.BIND_DEVICE_ADMIN">
        <meta-data
            android:name="android.app.device_admin"
            android:resource="@xml/admin"/>

        <intent-filter>
            <action android:name="android.app.action.DEVICE_ADMIN_ENABLED" />
        </intent-filter>
    </receiver>
    <receiver android:name=".Receiver">
      <intent-filter>
        <action android:name="android.intent.action.USER_PRESENT" />
        <action android:name="android.intent.action.ACTION_SHUTDOWN" />
     </intent-filter>
    </receiver>
    <activity android:name=".LockScreen"></activity>
</application>

`

private ActionBar actionBar;
private ViewPager viewer;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
            WindowManager.LayoutParams.FLAG_FULLSCREEN);
    setContentView(R.layout.lockscreen);
    actionBar = getSupportActionBar();
    actionBar.hide();

    IntentFilter filter = new IntentFilter(Intent.ACTION_SCREEN_ON);
    filter.addAction(Intent.ACTION_SCREEN_OFF);
    BroadcastReceiver mReceiver = new Receiver();
    registerReceiver(mReceiver, filter);

    viewer = (ViewPager) findViewById(R.id.viewr);
    viewer.setAdapter(new MyAdapter(getSupportFragmentManager()));
}

但是当用户按下电源按钮时，锁屏 activity 会在 1-3 秒后启动。当用户先按下电源按钮关闭屏幕时启动 activity 是否合适？我该怎么做？

感谢您的建议。（抱歉我的英语不好！）

Answer 1

First, unlike other broad casted intents, for Intent.ACTION_SCREEN_OFF and Intent.ACTION_SCREEN_ON you CANNOT declare them in your Android Manifest! I’m not sure exactly why, but they must be registered in an IntentFilter in your JAVA code

使用：

再次编辑

public class YourActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.YourLayout);

        IntentFilter filter = new IntentFilter(Intent.ACTION_SCREEN_ON);
        filter.addAction(Intent.ACTION_SCREEN_OFF);
        BroadcastReceiver mReceiver = new ScreenReceiver();
        registerReceiver(mReceiver, filter);
    }

    public class ScreenReceiver extends BroadcastReceiver{
        @Override
        public void onReceive(Context context, Intent intent) {

            if(intent.getAction().equals(Intent.ACTION_SCREEN_ON)){
                Log.w("BAM", "Screen went on");
            }

            else if(intent.getAction().equals(Intent.ACTION_SCREEN_OFF)){
                Log.w("BAM","Screen went off");
            }
        }
    }
}

已测试，成功！

屏幕打开时开始 activity

Start an activity when screen on

android

broadcastreceiver

lockscreen