设置Android设备WIFI在休眠时永不断开的代码实现

mainactivity如下:

package cc.ab;

import android.os.bundle;
import android.provider.settings;
import android.app.activity;
/**
 * demo描述:
 * 设置设备在睡眠期间始终保持wlan开启.
 * 
 * 参考资料:
 * 1 http://*.com/questions/8652031/how-to-modify-wi-fi-sleep-policy-programmatically/8655070#8655070
 * 2 http://blog.csdn.net/mrlixirong/article/details/24938637
 *  thank you very much
 *  
 * 注意事项:
 * 1 这里使用的是android.provider.settings.system.wifi_sleep_policy
 *  而不是settings.system.wifi_sleep_policy!!!!!!!!!!!!!!!!!!!!!!!
 *  
 * 2 权限<uses-permission android:name="android.permission.write_settings"/>
 * 
 * 3 在实际项目中,这么强制性地设置wifi在休眠时永不断开有些粗鲁了.
 *  可以先记录下wifi原本的策略,待我们的逻辑完成后再还原回去为好.
 */
public class mainactivity extends activity {

 @override
 protected void oncreate(bundle savedinstancestate) {
  super.oncreate(savedinstancestate);
  setcontentview(r.layout.main);
  setwifineversleep();
 }

 private void setwifineversleep(){
  int wifisleeppolicy=0;
  wifisleeppolicy=settings.system.getint(getcontentresolver(),
                    android.provider.settings.system.wifi_sleep_policy,
                    settings.system.wifi_sleep_policy_default);
  system.out.println("---> 修改前的wifi休眠策略值 wifi_sleep_policy="+wifisleeppolicy);
  
  
  settings.system.putint(getcontentresolver(),
            android.provider.settings.system.wifi_sleep_policy,
            settings.system.wifi_sleep_policy_never);
  
  
  wifisleeppolicy=settings.system.getint(getcontentresolver(),
        android.provider.settings.system.wifi_sleep_policy,
        settings.system.wifi_sleep_policy_default);
    system.out.println("---> 修改后的wifi休眠策略值 wifi_sleep_policy="+wifisleeppolicy);
 }
 
}
<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"
 >

 <textview
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:text="@string/hello_world" />

</relativelayout>

代码如上，不过在实际项目中,这么强制性地设置wifi在休眠时永不断开有些粗鲁了.
可以先记录下wifi原本的策略,待我们的逻辑完成后再还原回去为好.