我不希望我的用户尝试下载任何东西,除非他们连接了Wi-Fi。然而,我似乎只能判断是否启用了Wi-Fi,但他们仍然可能有3G连接。

android.net.wifi.WifiManager m = (WifiManager) getSystemService(WIFI_SERVICE);
android.net.wifi.SupplicantState s = m.getConnectionInfo().getSupplicantState();
NetworkInfo.DetailedState state = WifiInfo.getDetailedStateOf(s);
if (state != NetworkInfo.DetailedState.CONNECTED) {
    return false;
}

然而,这种状态并不是我所期望的。即使Wi-Fi是连接的,我得到OBTAINING_IPADDR作为状态。


当前回答

这适用于最新版本的android:

fun getConnectionType(context: Context): ConnectivityType {
    var result = NONE
    val cm = context.getSystemService(Context.CONNECTIVITY_SERVICE) as ConnectivityManager?
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
        if (cm != null) {
            val capabilities = cm.getNetworkCapabilities(cm.activeNetwork)
            if (capabilities != null) {
                when {
                    capabilities.hasTransport(NetworkCapabilities.TRANSPORT_WIFI) -> {
                        result = WIFI
                    }
                    capabilities.hasTransport(NetworkCapabilities.TRANSPORT_CELLULAR) -> {
                        result = MOBILE_DATA
                    }
                    capabilities.hasTransport(NetworkCapabilities.TRANSPORT_VPN) -> {
                        result = VPN
                    }
                }
            }
        }
    } else {
        if (cm != null) {
            val activeNetwork = cm.activeNetworkInfo
            if (activeNetwork != null) {
                // connected to the internet
                when (activeNetwork.type) {
                    ConnectivityManager.TYPE_WIFI -> {
                        result = WIFI
                    }
                    ConnectivityManager.TYPE_MOBILE -> {
                        result = MOBILE_DATA
                    }
                    ConnectivityManager.TYPE_VPN -> {
                        result = VPN
                    }
                }
            }
        }
    }
    return result
}

enum class ConnectivityType {
    NONE,
    MOBILE_DATA,
    WIFI,
    VPN,
}

在清单中:

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

其他回答

我在我的应用程序中使用这个来检查活动网络是否为Wi-Fi:

ConnectivityManager cm = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo ni = cm.getActiveNetworkInfo();
if (ni != null && ni.getType() == ConnectivityManager.TYPE_WIFI)
{

    // Do your work here

}
ConnectivityManager manager = (ConnectivityManager) getSystemService(CONNECTIVITY_SERVICE);
boolean is3g = manager.getNetworkInfo(
                  ConnectivityManager.TYPE_MOBILE).isConnectedOrConnecting();
boolean isWifi = manager.getNetworkInfo(
                    ConnectivityManager.TYPE_WIFI).isConnectedOrConnecting();

Log.v("", is3g + " ConnectivityManager Test " + isWifi);
if (!is3g && !isWifi) {
    Toast.makeText(
        getApplicationContext(),
        "Please make sure, your network connection is ON ",
        Toast.LENGTH_LONG).show();
}
else {
    // Put your function() to go further;
}

添加到JAVA:

public boolean CheckWifiConnection() {
        ConnectivityManager conMgr = (ConnectivityManager) getSystemService (Context.CONNECTIVITY_SERVICE);
        if (conMgr.getActiveNetworkInfo() != null
                && conMgr.getActiveNetworkInfo().isAvailable()
                && conMgr.getActiveNetworkInfo().isConnected()) {
            return true;
        } else {
            return false;
        }
    }

在Manifest文件中添加以下权限:

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

Try

wifiManager.getConnectionInfo().getIpAddress()

这将返回0,直到设备有一个可用的连接(在我的机器上,三星SM-T280, Android 5.1.1)。

下面是我在我的应用程序中使用的实用方法:

public static boolean isDeviceOnWifi(final Context context) {
        ConnectivityManager connManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo mWifi = connManager.getNetworkInfo(ConnectivityManager.TYPE_WIFI);
        return mWifi != null && mWifi.isConnectedOrConnecting();
}