进度栏将无法完成

Question

I have a worker, and a progress bar. progress bar is in the View and the worker is in the model. I want to show progress bar to the user so they know how long they have to wait. for all results to finish populating.

Worker thread looks like this

Model

ManagementObjectSearcher MetaClasses = new ManagementObjectSearcher(CurrentScope, new SelectQuery("SELECT * FROM meta_class"));
int index = 0;
int Total = MetaClasses.Get().Count;
foreach (ManagementObject Metaclass in MetaClasses.Get())
{
    try
    {
        index++;
        BGW.ReportProgress((index * 100) / Total, Metaclass["__CLASS"].ToString());
    }
    catch { }
    Thread.Sleep(100);
}

the worker sends the information to the ProgressUpdated method, i did this so the UI updated with the availible data for the end user.

Model

public void Workers_Changed(object sender, ProgressChangedEventArgs e)
{
    Progress = e.ProgressPercentage;
    switch (TaskToRun)
    {
        case "NameSpace":
            {
                BaseClasses.Add(e.UserState.ToString());
                if (Progress == 100) { Thread.Sleep(200); }
                break;
            }
        case "Class":
            {
                return;
            }
    }
}

Again Works perfectly. My progress bar Value is bound as well.

XAML

<ProgressBar Height="20" Name="ProgressBar_WMI"
             Value="{Binding Progress,Mode=OneWay}"
             DockPanel.Dock="Top"
             Minimum="1"
             Maximum="100" Foreground="Red"  ValueChanged="ProgressBar_WMI_ValueChanged" />

Issue: when the progressbar hits about 95% it doesn't show as completed in the UI thread

View (Xaml.CS)

public void HideProgressBar()
{
    Thread.Sleep(3000);
    ProgressBar_WMI.Visibility = Visibility.Collapsed;
}

public void ProgressBar_WMI_ValueChanged(object sender, RoutedEventArgs e)
{
    if (ProgressBar_WMI.Value == ProgressBar_WMI.Maximum)
    {
        ProgressBar_WMI.Foreground = Brushes.Green;
        HideProgressBar();
    }
    else {
        ProgressBar_WMI.Foreground = Brushes.Red;
        ProgressBar_WMI.Visibility = Visibility.Visible;
    }
}

My idea is to have the bar hit to 100% completed and turn green to indicate that its completed and the disappear/collapse after 3 seconds.

Any Idea's?

Answer 1

I can see two possible reasons for your ProgressBar not reaching 100%. The first is simply because you might be hiding it as soon as it reaches that point and so, you never actually see it.

The other possible reason is that this calculation never reaches your maximum limit value:

BGW.ReportProgress((index * 100) / Total, Metaclass["__CLASS"].ToString());

Only you can verify that, but you might be losing some precision in the actual calculation by using int s here... I am aware that the ReportProgress method takes an int