不要以为Wifi的状态只有2个！<wbr></wbr>

Android下Wifi的状态实际上有5个，依次为：

0 --> WIFI_STATE_DISABLING

1 --> WIFI_STATE_DISABLED

2 --> WIFI_STATE_ENABLING

3 --> WIFI_STATE_ENABLED

4 --> WIFI_STATE_UNKNOWN

<wbr></wbr>

每当该状态有变化时，系统都会发出“WIFI_STATE_CHANGED_ACTION”广播事件。

<wbr></wbr>

以下的receiver仅供参考：

（注册过程如下：

<wbr><wbr><wbr><wbr> mWifiStateReceiver = new WifiStateReceiver();</wbr></wbr></wbr></wbr>

<wbr><wbr><wbr><wbr> registerReceiver(mWifiStateReceiver, new IntentFilter(WifiManager.WIFI_STATE_CHANGED_ACTION));</wbr></wbr></wbr></wbr>

注销过程：

<wbr><wbr><wbr><wbr> unregisterReceiver(mWifiStateReceiver);<br></wbr></wbr></wbr></wbr>

）

<wbr></wbr>

class WifiStateReceiver extends BroadcastReceiver {<wbr><wbr><wbr><wbr><wbr><br><wbr><wbr><wbr>public void onReceive(Context c, Intent intent) {<br><wbr><wbr><wbr><wbr><wbr>Bundle bundle = intent.getExtras();<br><wbr><wbr><wbr><wbr><wbr>int oldInt = bundle.getInt("<span style="color:#ed1c24;">previous_wifi_state</span>");<br><wbr><wbr><wbr><wbr><wbr>int newInt = bundle.getInt("<span style="color:#ed1c24;">wifi_state</span>");<br><wbr><wbr><wbr><wbr><wbr>String oldStr = (oldInt&gt;=0 &amp;&amp; oldInt&lt;WIFI_STATES.length) ?WIFI_STATES[oldInt] :"?";<br><wbr><wbr><wbr><wbr><wbr>String newStr = (newInt&gt;=0 &amp;&amp; oldInt&lt;WIFI_STATES.length) ?WIFI_STATES[newInt] :"?";<br><wbr><wbr><wbr><wbr><wbr>Log.e(TAG, "oldS="+oldStr+", newS="+newStr);<br><wbr><wbr><wbr><wbr><wbr>if(newInt==WifiManager.WIFI_STATE_DISABLED || newInt==WifiManager.WIFI_STATE_ENABLED) {<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr> onWifiStateChange();<wbr> //<wbr>define this function elsewhere!<br><wbr><wbr><wbr><wbr><wbr>} else if(newInt==WifiManager.WIFI_STATE_DISABLING ||</wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr>

<wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr> newInt==WifiManager.WIFI_STATE_ENABLING)</wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr>

<wbr><wbr><wbr><wbr><wbr>{<br><wbr><wbr><wbr><wbr><wbr><wbr>chkbox_wifi.setText(newStr);<br><wbr><wbr><wbr><wbr><wbr>} else {<br><wbr><wbr><wbr><wbr><wbr><wbr>newStr += " (Is wpa_supplicant.conf readable?)";<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr>chkbox_wifi.setText(newStr);<br><wbr><wbr><wbr><wbr><wbr>}<br><wbr><wbr><wbr><wbr>}<br>}</wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr>

<wbr></wbr>

// 显示Wifi状态以及ip地址:

public static String StringizeIp(int ip) {
<wbr><wbr>int ip4 = (ip&gt;&gt;24) &amp; 0x000000FF;<br><wbr><wbr>int ip3 = (ip&gt;&gt;16) &amp; 0x000000FF;<br><wbr><wbr>int ip2 = (ip&gt;&gt; 8 )&amp; 0x000000FF;<br><wbr><wbr>int ip1 = ip<wbr><wbr><wbr><wbr><wbr><wbr> &amp; 0x000000FF;<br><wbr><wbr>return Integer.toString(ip1) + "." + ip2 + "." + ip3 + "." + ip4;<br>}</wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr>

private void onWifiStateChange() {

<wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr> String ip_str = "";</wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr>

<wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>WifiInfo info = mMainWifi.getConnectionInfo();<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>if(info != null) {<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>int ipaddr = info.getIpAddress();<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>ip_str = " (ip="+StringizeIp(ipaddr)+")";<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr>}<br><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr>

<wbr><wbr><wbr><wbr><wbr><wbr><wbr> if(mMainWifi.isWifiEnabled()==true)</wbr></wbr></wbr></wbr></wbr></wbr></wbr>

<wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr> chkbox_wifi.setText("Wifi is on [" + ip_str + "]");</wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr>

<wbr><wbr><wbr><wbr><wbr><wbr><wbr> else</wbr></wbr></wbr></wbr></wbr></wbr></wbr>

<wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr><wbr> chkbox_wifi.setText("Wifi is off");</wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr>

}

<wbr></wbr>

很多google出来的代码并未提及wifi的五个状态，实际上这在文档中说得很清楚。如果以为只有2个状态，那么，不仅状态监视会出问题，而且可能在监视到状态变化时作出错误的行为（你的onReceive()函数是否类似于多调用了几次？）。

原文地址：http://blog.sina.com.cn/s/blog_3e3fcadd0100n8rc.html

更多相关文章

  1. android 权限明细
  2. Android(安卓)读SIM卡信息
  3. android五个进程等级
  4. Android(安卓)读SIM卡信息
  5. selector in Android
  6. Android下打开/关闭wifi 及 状态(5个)的监视
  7. android List拖动时背景变化
  8. Android深入浅出系列课程---Lesson6 AAF110503_Activity状态保存
  9. Android底部导航栏实现（二）之RadioGroup

随机推荐

  1. 自定义 SeekBar 样式 详解
  2. Rockie's Android Porting Guide（3）——Add
  3. 关于Android音频、视频录制类MediaRecord
  4. Android自动化测试工具——Monkey
  5. android点滴
  6. android 布局实例解析 柱状图效果
  7. 开源终端Android Terminal Emulator
  8. 系出名门Android(2) - 布局(Layout)和菜
  9. Freeline 一款 Android平台上的秒级编译
  10. Android下使用Socket连接网络电脑