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
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。
其他回答
由于方法NetworkInfo.isConnected()现在在API-23中已弃用，下面是一个方法，它可以检测Wi-Fi适配器是否打开，并使用WifiManager连接到接入点:
private boolean checkWifiOnAndConnected() {
WifiManager wifiMgr = (WifiManager) getSystemService(Context.WIFI_SERVICE);
if (wifiMgr.isWifiEnabled()) { // Wi-Fi adapter is ON
WifiInfo wifiInfo = wifiMgr.getConnectionInfo();
if( wifiInfo.getNetworkId() == -1 ){
return false; // Not connected to an access point
}
return true; // Connected to an access point
}
else {
return false; // Wi-Fi adapter is OFF
}
}
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;
}
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
}
在新版Android中
private void getWifiInfo(Context context) {
ConnectivityManager connManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
Network[] networks = connManager.getAllNetworks();
if(networks == null || networks.length == 0)
return;
for( int i = 0; i < networks.length; i++) {
Network ntk = networks[i];
NetworkInfo ntkInfo = connManager.getNetworkInfo(ntk);
if (ntkInfo.getType() == ConnectivityManager.TYPE_WIFI && ntkInfo.isConnected() ) {
final WifiManager wifiManager = (WifiManager) context.getSystemService(Context.WIFI_SERVICE);
final WifiInfo connectionInfo = wifiManager.getConnectionInfo();
if (connectionInfo != null) {
// add some code here
}
}
}
}
还要加上前提
这适用于Q之前和之后的Android设备
fun isWifiConnected(context: Context):Boolean {
val cm = context.getSystemService(Context.CONNECTIVITY_SERVICE) as ConnectivityManager
return if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
val capabilities = cm.getNetworkCapabilities(cm.activeNetwork)
capabilities?.hasTransport(NetworkCapabilities.TRANSPORT_WIFI)==true
} else {
val activeNetwork: NetworkInfo? = cm.activeNetworkInfo
activeNetwork?.typeName?.contains("wifi",ignoreCase = true)?:false
}
}
