Android MAC-Address上的BUG或正常行为？

Question

我正在尝试获取Wifi的MAC地址、BSSID和LINK_speed。我注意到，即使在Wifi关闭的情况下，这三个选项也都显示了值。我关掉手机，然后再打开，但没有打开wifi。这个应用程序在询问这三个项目时会崩溃，我无法尝试/捕捉错误。如果我打开wifi，然后关闭，我可以询问项目和应用程序运行正常。就像BSSID和LINKSPEED一样，BSSID和LINKSPEED是真正的“最后”BSSID和“最后”LINKSPEED。是不是开机后对MAC地址视而不见，而不是在正常行为下打开wifi ?有没有办法捕获错误以防止应用程序被强行关闭？

    WifiManager wifi;
    wifi = (WifiManager) this.getSystemService(Context.WIFI_SERVICE);
    WifiInfo wifiInfo = wifi.getConnectionInfo();
    int ipAddress = wifiInfo.getIpAddress();
    ipAddress = wifiInfo.getIpAddress();
    //above work no matter whether wifi on or off before

    String BSSID=wifiInfo.getBSSID();  //<<<<< ERRORS FORCE CLOSE IF NOT EVER CONNECTED
    int WifiLinkSpeed=wifiInfo.getLinkSpeed(); printi("link speed",WifiLinkSpeed);  
    String MacAddress=wifiInfo.getMacAddress(); Log.e("MAC address",MacAddress);
    //All three of these FORCE close if WIFI has never been turn on

Answer 1

尝尝这个,

WifiManager wifiManager = (WifiManager) Settings.cntxt.getSystemService(Context.WIFI_SERVICE);
WifiInfo wifiInfo = wifiManager.getConnectionInfo();
strMacAddr = wifiInfo.getMacAddress();
if(strMacAddr==null) {
    strMacAddr = "Unknown MAC";
}

Answer 2

尽管你确实说过你尝试过尝试/捕捉...您捕获了哪些错误/异常？显然不是正确的。

我已经有一段时间没有做过Android编程了，但这就是问题的症结所在……当您尝试这些函数时，找出触发了哪个异常。

try {
    // don't declare variables inside block, you'll limit scope
    BSSID=wifiInfo.getBSSID();  //<<<<< ERRORS FORCE CLOSE IF NOT EVER CONNECTED
    WifiLinkSpeed=wifiInfo.getLinkSpeed(); printi("link speed",WifiLinkSpeed);  
    MacAddress=wifiInfo.getMacAddress(); Log.e("MAC address",MacAddress);
    //All three of these FORCE close if WIFI has never been turn on
}
catch { /* something bad happened, handle it */ }
// continue on since all is good in the world today...