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
您应该能够使用ConnectivityManager来获取Wi-Fi适配器的状态。从那里你可以检查它是否连接，甚至可用。
ConnectivityManager connManager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo mWifi = connManager.getNetworkInfo(ConnectivityManager.TYPE_WIFI);
if (mWifi.isConnected()) {
// Do whatever
}
注意:应该注意(对于这里的n00bies)，您需要添加
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
到你的
AndroidManifest.xml来工作。
注2:公共NetworkInfo getNetworkInfo (int networkType)现在已弃用:
此方法在API级别23中已弃用。这个方法没有 支持多个相同类型的网络连接。使用 getAllNetworks()和getNetworkInfo(android.net.Network)代替。
注3:public static final int TYPE_WIFI现在已弃用:
此常量在API级别28中已弃用。 应用程序应该使用networkcapabilities . hatransporsport (int)或requestNetwork(NetworkRequest, NetworkCallback)来请求一个合适的网络。对于支持的传输。
我简单地使用以下方法:
SupplicantState supState;
wifiManager = (WifiManager) getSystemService(Context.WIFI_SERVICE);
WifiInfo wifiInfo = wifiManager.getConnectionInfo();
supState = wifiInfo.getSupplicantState();
它将在调用getSupplicantState()时返回这些状态之一;
ASSOCIATED - Association completed. ASSOCIATING - Trying to associate with an access point. COMPLETED - All authentication completed. DISCONNECTED - This state indicates that client is not associated, but is likely to start looking for an access point. DORMANT - An Android-added state that is reported when a client issues an explicit DISCONNECT command. FOUR_WAY_HANDSHAKE - WPA 4-Way Key Handshake in progress. GROUP_HANDSHAKE - WPA Group Key Handshake in progress. INACTIVE - Inactive state. INVALID - A pseudo-state that should normally never be seen. SCANNING - Scanning for a network. UNINITIALIZED - No connection.
使用WifiManager你可以做到:
WifiManager wifi = (WifiManager) getSystemService (Context.WIFI_SERVICE);
if (wifi.getConnectionInfo().getNetworkId() != -1) {/* connected */}
方法getNeworkId只有在没有连接到网络时才返回-1;
这是一个更简单的解决方案。参见Stack Overflow 在Android上检查是否启用Wi-Fi。
注:不要忘记将代码添加到manifest.xml文件中以允许权限。如下图所示。
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" >
</uses-permission>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" >
</uses-permission>
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE" >
</uses-permission>
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
}
