I am building Xamarin.Forms app that pretty much works offline except a few calls to a web-service. Now I need to check internet connection just before I make a request, but I cannot find a solution or an answer that would allow checking internet connection only once not continuously
You could use Xamarin.Essentials and specifically Connectivity class as CrossConnectivity features have been consolidated into Xamarin.Essentials toolkit.
var connect = Connectivity.NetworkAccess;
if (connect != NetworkAccess.Internet) Message = "Device does not have internet access.";
else { // api call }
You can use the ConnectivityPlugin by James Montemagno
Nuget can be found here
For check the internet you just have to do this:
if(CrossConnectivity.Current.IsConnected)
{
//You are connected to the internet!!!
}
You might wanna check this: https://jamesmontemagno.github.io/ConnectivityPlugin/CheckingConnectivity.html
Xamarin Essentials Connectivity is also an option.
if (Connectivity.NetworkAccess == NetworkAccess.Internet)
{
//You are connected to the internet!!!
}
Related
I am using Xam.Connectivity plugin for checking Internet Connectivity.
Here is my code
if (!CrossConnectivity.Current.IsConnected)
{
DependencyService.Get<ISQLite>().ShowSnackBar("No Internet Connection");
}
If I need to check internet every second then I am calling this code every second using Device Timer.This code is good,but I want to detect when Internet goes down with out using any Timer.
So how to achieve this?
I think you would be better off to use the event that is implemented for this.
CrossConnectivity.Current.ConnectivityChanged += async (sender, args) =>
{
if (!args.IsConnected)
DependencyService.Get<ISQLite>().ShowSnackBar("No Internet Connection");
};
Whenever the connection state now changes, you will be notified automatically.
Please note that you are using the "old" plugin. This functionality is now also captured in the Xamarin.Essentials library which works similar, but will probably be the maintained version from now.
I am looking for an example to list all wifi connections that are availables by using Xamarin Forms.
All of examples that I found was to check if the current connection is on or off. But I'd like to list all avaliable connections and get all of information about them.
I am not sure if this plugin "Plugin.Connectivity" could help me but it was the more close I got from my goal.
The Connectivity (which is now part of Xamarin.Essentials) plugin is not going to help with this, unfortunately. It only allows you to see if you have a connection and tells you something about that.
As far as I know, there is no library for this and you will have to write custom code for this. I'm not sure what platforms you are targeting, I'll assume iOS and Android.
For iOS, you probably want to look at the NEHotspotHelper and list the SupportedNetworkInterfaces property. And do something like this:
foreach (var network in NEHotspotHelper.SupportedNetworkInterfaces)
Console.WriteLine(network.Ssid);
Don't forget to enable the NetworkExtensions entitlement in the Entitlements.plist
For Android, the code could look something like this:
WlanClient client = new WlanClient();
foreach ( WlanClient.WlanInterface wlanIface in client.Interfaces )
{
// Lists all networks
Wlan.WlanAvailableNetwork[] networks = wlanIface.GetAvailableNetworkList( 0 );
foreach ( Wlan.WlanAvailableNetwork network in networks )
{
Console.WriteLine( "Found network with SSID {0}.", GetStringForSSID(network.dot11Ssid));
}
}
On Android, you will need an extra permission to be able to do this.
To make it suitable for Forms, wrap it into a DependencyService and move back and forth the information you need.
I can not find how to start WPS client in Windows 10 from command prompt or powershell. When I used Linux, everything was really ease with wla_supplicant (wpa_cli wps_pbc). Is there something similar in Windows?
Does anyone know how to set up Wi-Fi network (over WPS) key without human input in Windows?
I also tried WCN (Windows Connect Now) from Microsoft as it implements WPS features. I got also samples from Windows SDK on WCN, but they could not get key by WPS (it faild). But if I use Windows user interface to connect wiothout PIN, everyting seems to be pretty fine.
I am sure that there is possibility to do that, it is very important to perform Wifi Protected Setup by button start from the command prompt or app (C++/C#) without human intrusion or input (once WPS is on air, Windows should automatically get the network key and connect then).
I don't know if it's too late to answer, just put what I know in here and hope it can help.
First, if your system has updated to 16299(Fall Creator Update), you can just simply use new wifi api from UWP.
Install newest Windows SDK, create a C# console project, target C# version to at least 7.1, then add two reference to the project.
C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework.NETCore\v4.5\System.Runtime.WindowsRuntime.dll
C:\Program Files (x86)\Windows Kits\10\UnionMetadata\10.0.16299.0\Windows.winmd
After all of that , code in below should work.
using System;
using System.Threading.Tasks;
using Windows.Devices.Enumeration;
using Windows.Devices.WiFi;
class Program
{
static async Task Main(string[] args)
{
var dic = await DeviceInformation.FindAllAsync(WiFiAdapter.GetDeviceSelector());
if (dic.Count > 0)
{
var adapter = await WiFiAdapter.FromIdAsync(dic[0].Id);
foreach (var an in adapter.NetworkReport.AvailableNetworks)
{
if (an.Ssid == "Ssid which you want to connect to.")
{
// Fouth parameter which is ssid can not be set to null even if we provided
// first one, or an exception will be thrown.
await adapter.ConnectAsync(an, WiFiReconnectionKind.Manual, null, "",
WiFiConnectionMethod.WpsPushButton);
}
}
}
}
}
Build and run the exe, then push your router's button, your pc will be connect to the router.
But if you can not update to 16299, WCN will be your only choice. You may already notice that if call IWCNDevic::Connect frist with push-button method, the WSC(Wifi Simple Configuration) session will fail. That's because WNC would not start a push-button session as a enrollee, but only as a registrar. That means you have to ensure that router's button has been pushed before you call IWCNDevic::Connect. The way to do that is using Native Wifi api to scan your router repeatedly, analyse the newest WSC information element from the scan result, confirm that Selected Registrar attribute has been set to true and Device Password Id attribute has been set to 4. After that, query the IWCNDevice and call Connect function will succeed. Then you can call IWCNDevice::GetNetworkProfile to get a profile that can use to connect to the router. Because it's too much of code, I will only list the main wifi api that will be used.
WlanEnuminterfaces: Use to get a available wifi interface.
WlanRegisterNotification: Use to register a callback to handle scan an connect results.
WlanScan: Use to scan a specified wifi BSS.
WlanGetNetworkBsslist: Use to get newest BSS information after scan.
WlanSetProfile: Use to save profile for a BSS.
WlanConnect: Use to connect to a BSS.
And about the WSC information element and it's attributes, you can find all the information from Wi-Fi Simple Configuration Technical Specification v2.0.5.
For Krisz. About timeout.
You can't cast IAsyncOperation to Task directly. The right way to do that is using AsTask method. And also, you should cancel ConnectAsync after timeout.
Sample code:
var t = adapter.ConnectAsync(an, WiFiReconnectionKind.Manual, null, "",
WiFiConnectionMethod.WpsPushButton).AsTask();
if (!t.Wait(10000))
t.AsAsyncOperation().Cancel();
This may well be a duplicate question, but no answer from an existing question has solved my problem.
I have a WebAPI end point running on my dev machine. I've configured it to run on
.UseUrls("http://localhost:57971", "http://10.0.2.2:57971", "http://192.168.44.1:57971", "http://192.168.1.48:57971", "http://*:57971")
where:
192.168.44.1 is Desktop Adapter #2 on the emulator Networks settings tab
10.0.2.2 is the special address for the Android emulator, as set out in Google's doco (possibly not relevant to Xamarin) and
192.168.1.48 is my local IP address for my dev machine.
I have created a firewall rule permitting connections on TCP port 57971.
I researched this pretty heavily and heeded instructions such as those set out here http://briannoyesblog.azurewebsites.net/2016/03/06/calling-localhost-web-apis-from-visual-studio-android-emulator/
I'm kinda out of ideas. The annoying thing is, it fails silently. There is no exception and the output just basically shows the different threads exiting with code 0. And the application keeps running i.e. the debugging session is not returning the IDE to a "code entry" state. This may suggest that something else its at play here.
The code looks pretty innocuous to me:
protected async Task<T> GetAsync<T>(string url)
where T : new()
{
HttpClient httpClient = CreateHttpClient();
T result;
try
{
var response = await httpClient.GetStringAsync(url);
result = await Task.Run(() => JsonConvert.DeserializeObject<T>(response));
}
catch
{
result = new T();
}
return result;
}
I'm using Visual Studio 2015.
I'm using the Visual Studio emulator https://www.visualstudio.com/vs/msft-android-emulator/
Any idea how I can get wheels on the ground on this thing?
Is there a way to Ping my machine from the emulator?
Thanks
I got this working by using 169.254.80.80 i.e. I added it to the list of urls which the API serves and called that ip address from the Xamarin app.
So, in Program.cs became simple:
.UseUrls("http://localhost:57971", "http://169.254.80.80:57971")
I also had to add it to the bindings element ApplicationConfig file in the hidden .vs folder of the ASP.NET API solution. Not sure why it had to be 169.254.80.80, as that was Desktop Adapter #4.
That got it working.
How can I disconnect/close all sockets on server side ?
Maybe restarting the socket.io module from the server side ?
(using the lateste socket.io)
Unfortunately, socket.io does not have a publicly documented interface that has been the same from one version to the next to do such a basic function as iterate all connected sockets. If you want to follow the entire history of various ways to do this, then you can follow the whole version history in this question: Socket.IO - how do I get a list of connected sockets/clients?, but you have to pay attention only to answers that apply to specific socket.io versions you are using and then test them for your specific version.
As of Aug 2018, attempting to use only documented interfaces in socket.io, one could use either of these to get a list of connected sockets and then just iterate over them to disconnect them as shown above:
function getConnectedSockets() {
return Object.values(io.of("/").connected);
}
getConnectedSockets().forEach(function(s) {
s.disconnect(true);
});
Depending upon the client configuration, the clients may try to reconnect.
You could also just maintain your own connect socket list:
const connectedSockets = new Set();
io.on('connection', s => {
connectedSockets.add(s);
s.on('disconnect', () => {
connectedSockets.delete(s);
});
});
function getConnectedSockets() {
return Array.from(connectedSockets);
}
getConnectedSockets().forEach(function(s) {
s.disconnect(true);
});
If you are using an older version of socket.io (particularly before v1.4), you will have to either test this to make sure it works in your older version or follow the version history in the above mentioned reference and find an answer there that targets your specific version of socket.io.
For me, jfriend00's solution didn't work (as of today).
I had to do this:
Object.keys(io.sockets.sockets).forEach(function(s) {
io.sockets.sockets[s].disconnect(true);
});