我不能等待等待？

Question

Visual Studio抱怨如下:

public RelayCommand SendRegistrationCommand { get; private set; }
public async void SendRegistration()
{
    HttpClient client = new HttpClient();
    var response = await client.GetStringAsync("url");

    // ... todo
}

Cannot await 'System.Threading.Tasks.Task<string>'

我以为我之前已经这样做了,GetStringAsync是不是值得期待？

Answer 1

您可能正在瞄准.NET 4.0.

如果可以,请切换到支持async/await语义的.NET 4.5.

如果不能,请考虑使用Async Targeting Pack:https://www.nuget.org/packages/Microsoft.CompilerServices.AsyncTargetingPack

编辑

根据评论,Microsoft.Bcl.Async应该使用:https://www.nuget.org/packages/Microsoft.Bcl.Async

Answer 2

确保 client.GetStringAsync("url") 是异步任务

private async Task GetStringAsync(string str)
{
}