我試圖測試ModernHttpClient
的速度,當我遇到以下情況時:標籤未更新,並且按鈕在下面的代碼中一次都未被禁用(在Nexus 5x上測試),而是等待點擊到一直處理到最後!那是什麼,我的一個錯誤,一個錯誤或一個奇怪的「優化」功能?爲什麼標籤文本不能即刻更改?
的Page1.xaml:
<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
x:Class="ModernClientBenchmark.Page1">
<StackLayout>
<Button Text="Run the test!" Clicked="OnTestClicked" x:Name="btn"></Button>
<Label Text="here we are" x:Name="labl"/>
</StackLayout>
</ContentPage>
Page1.xaml.cs:
public partial class Page1 : ContentPage
{
private const int TESTQ = 3;
public Page1()
{
InitializeComponent();
}
private async void OnTestClicked(object sender, EventArgs e)
{
btn.IsEnabled = false;
var l1 = new double[TESTQ];
var l2 = new double[TESTQ];
for (int i = 0; i < TESTQ; i++)
{
Device.BeginInvokeOnMainThread(() => labl.Text = "Step " + i);
l2[i] = (await ManagedNetworkSpeedAsync(true)).Milliseconds;
//l1[i] = (await NativeNetworkSpeedAsync(true)).Milliseconds;
}
//var avg1 = l1.Sum()/TESTQ;
//var avg2 = l2.Sum()/TESTQ;
var a = 234;
}
public static async Task<TimeSpan> NativeNetworkSpeedAsync(bool secure)
{
using (var client = new HttpClient(new NativeMessageHandler()))
{
return await RunTestAsync(secure, client);
}
}
public static async Task<TimeSpan> ManagedNetworkSpeedAsync(bool secure)
{
using (var client = new HttpClient())
{
return await RunTestAsync(secure, client);
}
}
public static async Task<TimeSpan> RunTestAsync(bool secure, HttpClient client)
{
try
{
var start = DateTime.Now;
for (var i = 0; i <= 1; i++)
{
var result = client.GetStreamAsync(secure ? "https://xamarin.com" : "http://httpbin.org/ip").Result;
result.Dispose();
}
return DateTime.Now - start;
}
catch (Exception ex)
{
var a = 234;
}
return new TimeSpan();
}
}
我使用'await'所以代碼應該在不同的線程中運行。對? – nicks
@NikaGamkrelidze在你的情況,是的,BTW async/await本身並不意味着「其他線程」。 –
那麼,你在說什麼?如果代碼在不同的線程中運行,爲什麼UI線程被阻塞? – nicks