startscan（）已导致10分钟后，当手机进入空闲状态 [英] startscan() has result after 10 min when phone get into idle state

问题描述

我试图扫描WiFi网络，每2分钟。我使用的服务的。当手机处于正在使用主动或之后 startscan（）叫我得到 SCAN_RESULTS_AVAILABLE_ACTION 6秒。因此，我可以为wifis定期扫描。但之后手机一直没有感动任何人在一定时间内（10分钟）startscan（）停止工作和10分钟得到结果之后。任何人都经历过这样？

I am trying to scan wifi networks every 2 minutes. I am using service for that. When the phone is "active" or "in use" after startscan() called I get SCAN_RESULTS_AVAILABLE_ACTION in 6 sec. So i can scan for wifis periodically. But after the phone has not been touched by anyone for a certain time (10 min) startscan() stops "working" and only after 10 min getting result. Anybody experienced this?

推荐答案

根据这我已经找到了解决办法 - 这是因为<一个href="http://developer.android.com/reference/android/provider/Settings.Global.html#WIFI_SLEEP_POLICY_DEFAULT"相对=nofollow>在WiFi休眠策略。 你可以设置你的无线设备永远不会进入睡眠状态，这一点：

According to this I have found the solution - this is because the Wifi sleep policy. You can set your wifi device never goes to sleep with this:

Settings.System.putInt(getContentResolver(),
              Settings.System.WIFI_SLEEP_POLICY, 
              Settings.System.WIFI_SLEEP_POLICY_NEVER);

当然，您在的Andr​​oidManifest.xml 添加此权限的文件：

Be sure, that you added this permission in AndroidManifest.xml file:

<uses-permission android:name="android.permission.WRITE_SETTINGS"/>

在扫描期间将5-15​​s - 这是自动的 - 你不需要调用 startscan（）。关于Android扫描过程的详细信息，可以发现<一href="http://android.stackexchange.com/questions/37621/where-can-i-find-settings-for-wifi-internal-scan-period">here.
修改
这也许是更好的解决方案，如果你只是想扫描热点：
WIFI_MODE_SCAN_ONLY < /一> - 它可以通过激活：

the scanning period will be 5-15s - and this is automatic - you dont need to call startscan(). more info about Android scanning process can be found here.

maybe this is even better solution if you only want to scan for hotspots:
WIFI_MODE_SCAN_ONLY - it can be activated by:

WifiManager wm = (WifiManager) context.getSystemService(Context.WIFI_SERVICE);
WifiLock wifiLock = wm.createWifiLock(WifiManager.WIFI_MODE_SCAN_ONLY , "MyWifiLock");
if(!wifiLock.isHeld()){
    wifiLock.acquire();
}

不要忘记将其释放，约 WifiLock 详细信息的此处
也可以定义此权限：

dont forget to release it, more info about WifiLock here
also define this permission:

<uses-permission android:name="android.permission.WAKE_LOCK"/>

EDIT2 这个工程，以及：
您可以启用，并定期禁用无线：

Edit2 this works as well:
you can enable, and disable wifi periodically:

WifiManager wm = (WifiManager) context.getSystemService(Context.WIFI_SERVICE);
if(wm.isWifiEnabled() == false) {
    wm.setWifiEnabled(true);
}

然后扫描后您的BroadcastReceiver获得包含动作 WIFI_STATE_ENABLED 额外

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