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。
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。
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" />
你可以打开WIFI,如果它没有被激活如下
1. 查看@Jason Knight回复的WIFI状态
2. 如果没有激活,请激活它
不要忘记在manifest文件中添加WIFI权限
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
您的Java类应该是这样的
public class TestApp extends Activity {
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
//check WIFI activation
ConnectivityManager connManager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo mWifi = connManager.getNetworkInfo(ConnectivityManager.TYPE_WIFI);
if (mWifi.isConnected() == false) {
showWIFIDisabledAlertToUser();
}
else {
Toast.makeText(this, "WIFI is Enabled in your devide", Toast.LENGTH_SHORT).show();
}
}
private void showWIFIDisabledAlertToUser(){
AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(this);
alertDialogBuilder.setMessage("WIFI is disabled in your device. Would you like to enable it?")
.setCancelable(false)
.setPositiveButton("Goto Settings Page To Enable WIFI",
new DialogInterface.OnClickListener(){
public void onClick(DialogInterface dialog, int id){
Intent callGPSSettingIntent = new Intent(
Settings.ACTION_WIFI_SETTINGS);
startActivity(callGPSSettingIntent);
}
});
alertDialogBuilder.setNegativeButton("Cancel",
new DialogInterface.OnClickListener(){
public void onClick(DialogInterface dialog, int id){
dialog.cancel();
}
});
AlertDialog alert = alertDialogBuilder.create();
alert.show();
}
}