解决方案:
您可以使用DependencyService
来实现它。参考以下代码。
在 Forms 中,创建一个界面
using System;
namespace app1
{
public interface INetworkAvailable
{
bool IsNetworkAvailable();
}
}
在iOS项目中
using System;
using Xamarin.Forms;
using Foundation;
[assembly: Dependency(typeof(IsNetworkAvailableImplement))]
namespace xxx.iOS
{
public class IsNetworkAvailableImplement:INetworkAvailable
{
public IsNetworkAvailableImplement()
{
}
bool INetworkAvailable.IsNetworkAvailable()
{
NSString urlString = new NSString("http://captive.apple.com");
NSUrl url = new NSUrl(urlString);
NSUrlRequest request = new NSUrlRequest(url, NSUrlRequestCachePolicy.ReloadIgnoringCacheData, 3);
NSData data = NSUrlConnection.SendSynchronousRequest(request, out NSUrlResponse response, out NSError error);
NSString result = NSString.FromData(data,NSStringEncoding.UTF8);
if(result.Contains(new NSString("Success")))
{
return true;
}
else
{
return false;
}
}
}
}
不要忘记允许HTTP访问。在info.plist中添加以下代码
<key>NSAppTransportSecurity</key>
<dict>
<key>NSAllowsArbitraryLoads</key>
<true/>
</dict>
在Android项目中
using System;
using Java.Lang;
using Xamarin.Forms;
[assembly: Dependency(typeof(IsNetworkAvailableImplement))]
namespace xxx.Droid
{
public class IsNetworkAvailableImplement:INetworkAvailable
{
public IsNetworkAvailableImplement()
{
}
public bool IsNetworkAvailable()
{
Runtime runtime = Runtime.GetRuntime();
Process process = runtime.Exec("ping -c 3 www.google.com");
int result = process.WaitFor();
if(result==0)
{
return true;
}
else
{
return false;
}
}
}
}
现在你可以以形式调用它,就像
bool isAvailable= DependencyService.Get<INetworkAvailable>().IsNetworkAvailable();
if(isAvailable)
{
Console.WriteLine("network is available");
}
else
{
Console.WriteLine("network is unavailable");
}