WPF在异步等待模式中使用MVVM和WCF

Question

I'm building a WPF app that uses MVVM as pattern together with a WCF backend. My UI must always be responsive and for some controls the data can be up to 10 seconds to load.

Following code works well and is inside my viewmodel where ConfigurationsForInterface is an Observable type that is bound to my control:

ConfigurationsForInterface = new ObservableCollection<string>() { "Loading..." };      
ConfigurationsForInterface = await GetConfigurationInterfaceXAsync();

Method that works fine:

      public async Task<ObservableCollection<string>> GetConfigurationHL7Server5Async()
        {
            ObservableCollection<string> result;

            using (var localClient = new ManagerListenerClient(Globals.ChannelBinding, Globals.EndpointAddress))
            {               
                result = await  localClient.GetConfigurationsAsync("interfacex");
            }

            return result;
        }

Method that freezes my UI as I reuse the service client already opened in other areas of the app as I set a context for the service (user):

  public async Task<ObservableCollection<string>> GetConfigurationHL7Server5Async() { ObservableCollection<string> result; result = await Globals.Client.GetConfigurationsAsync("interfacex"); return result; } 

It seems like the WCF client is somehow bound to my UI thread and causes my UI to freeze until the data is loaded. I can see from my debugging that it does not wait in the method itself.

Can someone help me out why I cant reuse my WCF client object that is used elsewhere and not always in a async context like just sync calling the viewmodel

Answer 1

Thanks to @Rowbear I pinpointed the real issue.

I changed my binding from WsHttpBinding to NetTCPBinding and then everything runs nicely async. For my app I can easily use NetTCPBinding.

It seems that something is still going sync. in the WsHttpBinding implementation.

Thanks! for the advice.