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
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;
这个问题有点老了，但我用的就是这个。要求最低api级别21也考虑到废弃的Networkinfo api。
boolean isWifiConn = false;
ConnectivityManager connMgr = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
Network network = connMgr.getActiveNetwork();
if (network == null) return false;
NetworkCapabilities capabilities = connMgr.getNetworkCapabilities(network);
if(capabilities != null && capabilities.hasTransport(NetworkCapabilities.TRANSPORT_WIFI)){
isWifiConn = true;
Toast.makeText(context,"Wifi connected Api >= "+Build.VERSION_CODES.M,Toast.LENGTH_LONG).show();
}else{
Toast.makeText(context,"Wifi not connected Api >= "+Build.VERSION_CODES.M,Toast.LENGTH_LONG).show();
}
} else {
for (Network network : connMgr.getAllNetworks()) {
NetworkInfo networkInfo = connMgr.getNetworkInfo(network);
if (networkInfo.getType() == ConnectivityManager.TYPE_WIFI && networkInfo.isConnected()) {
isWifiConn = true;
Toast.makeText(context,"Wifi connected ",Toast.LENGTH_LONG).show();
break;
}else{
Toast.makeText(context,"Wifi not connected ",Toast.LENGTH_LONG).show();
}
}
}
return isWifiConn;
从API级别29开始，NetworkInfo类以及相关的访问方法(如connectivitymanager# getNetworkInfo()和connectivitymanager# getActiveNetworkInfo())都已弃用。
文档现在建议人们使用ConnectivityManager。NetworkCallback API用于异步回调监控，或使用connectivitymanager# getNetworkCapabilities或connectivitymanager# getLinkProperties来同步访问网络信息
调用者应该使用ConnectivityManager。NetworkCallback API来了解连接变化，或切换到使用connectivitymanager# getNetworkCapabilities或connectivitymanager# getLinkProperties来同步获取信息。
要检查是否连接了WiFi，下面是我使用的代码:
科特林：
val connMgr = applicationContext.getSystemService(Context.CONNECTIVITY_SERVICE) as ConnectivityManager?
connMgr?: return false
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
val network: Network = connMgr.activeNetwork ?: return false
val capabilities = connMgr.getNetworkCapabilities(network)
return capabilities != null && capabilities.hasTransport(NetworkCapabilities.TRANSPORT_WIFI)
} else {
val networkInfo = connMgr.activeNetworkInfo ?: return false
return networkInfo.isConnected && networkInfo.type == ConnectivityManager.TYPE_WIFI
}
Java:
ConnectivityManager connMgr = (ConnectivityManager) getApplicationContext().getSystemService(Context.CONNECTIVITY_SERVICE);
if (connMgr == null) {
return false;
}
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
Network network = connMgr.getActiveNetwork();
if (network == null) return false;
NetworkCapabilities capabilities = connMgr.getNetworkCapabilities(network);
return capabilities != null && capabilities.hasTransport(NetworkCapabilities.TRANSPORT_WIFI);
} else {
NetworkInfo networkInfo = connMgr.getActiveNetworkInfo();
return networkInfo.isConnected() && networkInfo.getType() == ConnectivityManager.TYPE_WIFI;
}
记住还要向Manifest文件添加ACCESS_NETWORK_STATE权限。
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)。
这对我来说很管用:
ConnectivityManager conMan = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
// Mobile
State mobile = conMan.getNetworkInfo(ConnectivityManager.TYPE_MOBILE).getState();
// Wi-Fi
State wifi = conMan.getNetworkInfo(ConnectivityManager.TYPE_WIFI).getState();
// And then use it like this:
if (mobile == NetworkInfo.State.CONNECTED || mobile == NetworkInfo.State.CONNECTING)
{
Toast.makeText(Wifi_Gprs.this,"Mobile is Enabled :) ....",Toast.LENGTH_LONG).show();
}
else if (wifi == NetworkInfo.State.CONNECTED || wifi == NetworkInfo.State.CONNECTING)
{
Toast.makeText(Wifi_Gprs.this,"Wifi is Enabled :) ....",Toast.LENGTH_LONG).show();
}
else
{
Toast.makeText(Wifi_Gprs.this,"No Wifi or Gprs Enabled :( ....",Toast.LENGTH_LONG).show();
}
并添加以下权限:
<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
