【发布时间】：2022-08-24 10:22:26
【问题描述】：
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# MainActivity.cs
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using System;
using Android.App;
using Android.Content.PM;
using Android.Runtime;
using Android.Views;
using Android.Widget;
using Android.OS;
using Android.Content;
using System.Collections.Generic;
using Android.Net.Wifi;
using System.Text;
using Java.Lang;
using Xamarin.Forms;
using StringBuilder = System.Text.StringBuilder;
using Menu = Android.Views.Menu;
using System.Threading.Tasks;
using System.Threading;
[assembly: Xamarin.Forms.Dependency(typeof(App1.Droid.Wifi))]
namespace App1.Droid
{
[Activity(Label = \"App1\", Icon = \"@mipmap/icon\", Theme = \"@style/MainTheme\", MainLauncher = true, ConfigurationChanges = ConfigChanges.ScreenSize | ConfigChanges.Orientation | ConfigChanges.UiMode | ConfigChanges.ScreenLayout | ConfigChanges.SmallestScreenSize )]
public class MainActivity : global::Xamarin.Forms.Platform.Android.FormsAppCompatActivity
{
protected override void OnCreate(Bundle savedInstanceState)
{
base.OnCreate(savedInstanceState);
Xamarin.Essentials.Platform.Init(this, savedInstanceState);
global::Xamarin.Forms.Forms.Init(this, savedInstanceState);
LoadApplication(new App());
}
public override void OnRequestPermissionsResult(int requestCode, string[] permissions, [GeneratedEnum] Android.Content.PM.Permission[] grantResults)
{
Xamarin.Essentials.Platform.OnRequestPermissionsResult(requestCode, permissions, grantResults);
base.OnRequestPermissionsResult(requestCode, permissions, grantResults);
}
}
public class Wifi : IWifi
{
private Context context = null;
public Wifi()
{
this.context = Android.App.Application.Context;
}
public async Task<IEnumerable<string>> GetAvailableNetworksAsync()
{
IEnumerable<string> availableNetworks = null;
// Get a handle to the Wifi
var wifiMgr = (WifiManager)context.GetSystemService(Context.WifiService);
var wifiReceiver = new WifiReceiver(wifiMgr);
await Task.Run(() =>
{
// Start a scan and register the Broadcast receiver to get the list of Wifi Networks
context.RegisterReceiver(wifiReceiver, new IntentFilter(WifiManager.ScanResultsAvailableAction));
availableNetworks = wifiReceiver.Scan();
});
return availableNetworks;
}
[BroadcastReceiver(Enabled = true, Exported = false)]
class WifiReceiver : BroadcastReceiver
{
private WifiManager wifi;
private List<string> wifiNetworks;
private AutoResetEvent receiverARE;
private Timer tmr;
private const int TIMEOUT_MILLIS = 10000; // 20 seconds timeout
public WifiReceiver()
{
}
public WifiReceiver(WifiManager wifi)
{
this.wifi = wifi;
wifiNetworks = new List<string>();
receiverARE = new AutoResetEvent(false);
}
public IEnumerable<string> Scan()
{
tmr = new Timer(Timeout, null, TIMEOUT_MILLIS, System.Threading.Timeout.Infinite);
wifi.StartScan();
receiverARE.WaitOne();
return wifiNetworks;
}
public override void OnReceive(Context context, Intent intent)
{
IList<ScanResult> scanwifinetworks = wifi.ScanResults;
foreach (ScanResult wifinetwork in scanwifinetworks)
{
wifiNetworks.Add(wifinetwork.Ssid);
}
receiverARE.Set();
}
private void Timeout(object sender)
{
// NOTE release scan, which we are using now, or we throw an error?
receiverARE.Set();
}
}
}
}
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# MainPage.xaml.cs
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using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Xamarin.Forms;
namespace App1
{
public interface IWifi
{
Task<IEnumerable<string>> GetAvailableNetworksAsync();
}
public partial class MainPage : ContentPage
{
public MainPage()
{
InitializeComponent();
}
private async void btn1_Clicked(object sender, EventArgs e)
{
IEnumerable<string> _wifiService = null;
_wifiService = await DependencyService.Get<IWifi>().GetAvailableNetworksAsync();
txtlog.Text = _wifiService.Count().ToString();
wifilist.ItemsSource = _wifiService;
//Device.StartTimer(new TimeSpan(0, 0, 60), () =>
//{
// // do something every 60 seconds
// Device.BeginInvokeOnMainThread(async () =>
// {
// IEnumerable<string> _wifiService = null;
// _wifiService = await DependencyService.Get<IWifi>().GetAvailableNetworksAsync();
// wifilist.ItemsSource = _wifiService;
// //txtlog.Text = _wifiService.Count<int>();
// //editLog.add
// });
// return true; // runs again, or false to stop
//});
//IEnumerable<string> test1 = new IEnumerable<string>;
//wifilist.
//ListView listview = FindViewByID<ListView>(Resources.Id)
//listview.setAdapter(adapter);
//List<string> lstItems;
//for (int i = 0; i < 10; i ++)
//{
//}
//wifilist.ItemsSource = lstItems;
}
}
}
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# MainPage.xaml.cs
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<?xml version=\"1.0\" encoding=\"utf-8\"?>
<manifest xmlns:android=\"http://schemas.android.com/apk/res/android\" android:versionCode=\"1\" android:versionName=\"1.0\" package=\"com.companyname.app1\" android:installLocation=\"auto\">
<uses-sdk android:minSdkVersion=\"21\" android:targetSdkVersion=\"30\" />
<application android:label=\"App1.Android\" android:theme=\"@style/MainTheme\"></application>
<uses-permission android:name=\"android.permission.ACCESS_NETWORK_STATE\" />
<uses-permission android:name=\"android.permission.ACCESS_FINE_LOCATION\" />
<uses-permission android:name=\"android.permission.ACCESS_WIFI_STATE\" />
<uses-permission android:name=\"android.permission.CHANGE_WIFI_STATE\" />
<uses-permission android:name=\"android.permission.ACCESS_COARSE_LOCATION\" />
</manifest>
我尝试按照示例进行操作，但无法获取 wifi 列表。我究竟做错了什么？ 这是我引用的示例的链接。
我打算使用 Android 10 或更高版本。 我将通过在开发环境中将 Android OS 放在 Raspberry Pi 板上进行测试。
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请张贴相关的位代码。发帖一切只是让任何人不太可能阅读所有内容以提供帮助。您是否收到任何错误或异常？您是否已调试代码以缩小问题范围？ \"I can\'t get the wifi list\" 对问题的描述不是很有帮助。
标签： xamarin.forms