Question

我在ViewModel中有一个后台工作程序。当执行按钮的命令时，我想在新线程中启动该过程。这是我的示例代码

private void ShowValidations(object obj)
        {
            progress = "Please Wait....";
            var worker = new BackgroundWorker();
            worker.WorkerReportsProgress = true;
            worker.DoWork += worker_DoWork;
            worker.ProgressChanged += worker_ProgressChanged;
            worker.RunWorkerCompleted += worker_RunWorkerCompleted;
}

在我的工作方法中

  private void worker_DoWork(object sender, DoWorkEventArgs e)
            {

                var worker = sender as BackgroundWorker;

                DoValidation();
                for(int i=0;i<100;i++)
                {
                    worker.ReportProgress(i); //Not sure here what should be written in the Background Worker Report progress event.
                }
            }

    private void worker_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
        {

            ViewSource.Source = _validationResults;
            ViewSource.View.Refresh();
            progress = "Validations Complete";
            Isindeterminate = false;
            //prvalue = 99;
        }

DoValidation是一种方法，可以像三层架构一样为其他类提取结果。

private void DoValidation()
        {
            try
            {

                if (!string.IsNullOrEmpty(_selectedEntity))
                {

                    var jobEngine = new JobEngine();
                    var jobId = JobEntities[0].JobId;                   
                    jobEngine.ProcessValidation(_selectedEntity, jobId); //Get results from other class.
                    _validationResults = _validations.ValidationSummary(_selectedEntity, jobId);  //_validationResults is an Observable Collection. 

                }

                else
                {
                    MessageBox.Show("Please select an Entity to validate");
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message + "Sorry we are having problems with " + _selectedEntity);
            }
        }

如何根据已完成的工作更新UI上的进度条。后台工作者的ProgressChanged事件应该是什么..这是我的查看代码。

  <ProgressBar HorizontalAlignment="Left" Minimum="1" Maximum="99" Height="20" Margin="424,24,0,0" Grid.Row="1" Value="{Binding prvalue,Mode=OneWay}" VerticalAlignment="Top" Width="194"/>
        <Label x:Name="LblprogressLabel" FontSize="14" Content="{Binding prvalue,Mode=OneWay}" HorizontalAlignment="Center" Margin="507,18,339,23" Grid.Row="1" Width="26"/>
        <Label Content="{Binding progress,Mode=OneWay}" FontSize="16" FontWeight="Bold" HorizontalAlignment="Left" Margin="623,20,0,0" Grid.Row="1" VerticalAlignment="Top" Width="227" Height="34"/>

请不要担心datacontext一切都很好。我不能写每个类的整个代码，因为它是如此巨大。请帮助!!!!

在MVVM中使用后台工作器更新UI

0 个答案: