WCF回调没有按预期工作

本文关键字：工作 回调 WCF | 更新日期: 2023-09-27 18:13:58

我创建了一个WCF服务，它对WPF客户端进行回调。我只是在WPF客户端的文本框中显示进度。我首先得到的是跨线程操作无效。然后修改客户端代码，使用Invoke()、BeginInvoke()等方法实现。现在，客户端代码只显示值100%。实际上它应该显示0-100%的值。有解决方案吗?

wcf service的代码:

namespace ReportService
{
    [ServiceBehavior(ConcurrencyMode=ConcurrencyMode.Reentrant,InstanceContextMode=InstanceContextMode.Single)]
    public class Report : IReportService
    {
        public void ProcessReport()
        {
            for (int i = 1; i <= 100; i++)
            {
                Thread.Sleep(1000);
              OperationContext.Current.GetCallbackChannel<IReportCallback>().ReportProgress(i);
            }
        }
    }
}

客户端代码:

namespace Report
{
    [CallbackBehavior(UseSynchronizationContext=false)]
    public partial class Form1 : Form,ReportService.IReportServiceCallback
    {
        delegate void delSetTxt(int percentCompleted);
        public Form1()
        {
            InitializeComponent();
        }
        private void button1_Click(object sender, EventArgs e)
        {
            InstanceContext ic= new InstanceContext(this);
            ReportService.ReportServiceClient client = new ReportService.ReportServiceClient(ic);
            client.ProcessReport();
        }
        public void ReportProgress(int percentCompleted)
        {
           // this.Invoke(new Action(() => { this.textBox1.Text = percentCompleted.ToString(); }));
            Thread t = new Thread(() => setTxt(percentCompleted));
            t.Start();
        }
        public void setTxt(int percentCompleted)
        {
            if (this.InvokeRequired)
            {
                this.BeginInvoke(new delSetTxt(setTxt), new object[] { percentCompleted });
                return;
            }
            this.textBox1.Text = percentCompleted.ToString() + " % complete";
        }
    }
}

WCF回调没有按预期工作

当调用服务时，GUI线程被卡在button_click方法中。所以GUI线程不能被冻结。
有(至少)两种可行的解决方案，我对它们进行了测试:

  1. 将[OperationContract(IsOneWay = true)]同时置于服务器和回调操作

  2. 把[OperationContract(IsOneWay = true)]放在回调操作上，不要用await/async锁定GUI线程:

    private async void button1_Click(object sender, EventArgs e)
{  
  InstanceContext ic = new InstanceContext(this);  
  ReportServiceClient client = new ReportServiceClient(ic);  
  await client.ProcessReportAsync();  
  //client.ProcessReport();  
}
好运

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