Get method in xamarin.Android REST service

Question

I want to get data from my api usign GetStringAsync Method in my xamarin.android app, but get error below:

System.Net.WebException: Error: ConnectFailure (Connection refused)

my code:

private static async void MainAsync()
{
     HttpClient client = new HttpClient();
     client.BaseAddress = new Uri("http://localhost:57558/");
     var getResponse = await client.GetStringAsync("/api/home");

     var getTask = client.GetStringAsync("/api/home");
     await getTask.ContinueWith((antecidentTask) =>
     {
         var result = antecidentTask.Result;
     });
}