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UI not updating fast

Good evening,

Following is the code I used for reading the files and folders from a drive etc.

Public Class LoadingBox

    Public counter As ULong
    Public OpenRecords As New Dictionary(Of String, MainWindow.records)
    Public Path As String
    Public Diskname As String
    Private WithEvents BKWorker As New BackgroundWorker()


    Public Sub New(ByVal _Path As String, ByVal _Diskname As String)

        ' This call is required by the designer.
        InitializeComponent()

        ' Add any initialization after the InitializeComponent() call.
        Path = _path
        Diskname = _diskname
    End Sub

    Private Sub GetStructure(ByVal tempdir As String, ByVal ParentID As String, ByVal DiskName As String)
        Dim maindir As DirectoryInfo = My.Computer.FileSystem.GetDirectoryInfo(tempdir)
        For Each Dir As DirectoryInfo In maindir.GetDirectories
            Try
                Dim d As New MainWindow.records
                d.Filename = Dir.Name
                d.Folder = True
                d.Rowid = Date.UtcNow.ToString() + counter.ToString()
                d.Size = 0
                d.ParentID = ParentID
                d.DiskName = DiskName
                d.DateCreated = Dir.CreationTimeUtc
                d.DateModified = Dir.LastWriteTimeUtc
                OpenRecords.Add(d.Rowid, d)
                'Label1.Content = "Processing: " + Dir.FullName
                BKWorker.ReportProgress(0, Dir.FullName)
                counter = counter + 1
                GetStructure(Dir.FullName, d.Rowid, DiskName)
            Catch ex As Exception

            End Try


        Next
        For Each fil As FileInfo In maindir.GetFiles
            Try
                Dim d As New MainWindow.records
                d.Filename = fil.Name
                d.Folder = False
                d.Rowid = Date.UtcNow.ToString() + counter.ToString()
                d.Size = fil.Length
                d.ParentID = ParentID
                d.DiskName = DiskName
                d.DateCreated = fil.CreationTimeUtc
                d.DateModified = fil.LastWriteTimeUtc
                OpenRecords.Add(d.Rowid, d)
                'Label1.Content = "Processing: " + fil.FullName
                BKWorker.ReportProgress(0, fil.FullName)
                counter = counter + 1
            Catch ex As Exception

            End Try

        Next
    End Sub

    Private Sub Window_Loaded(ByVal sender As System.Object, ByVal e As System.Windows.RoutedEventArgs) Handles MyBase.Loaded
        counter = 0
        BKWorker.WorkerReportsProgress = True
        AddHandler BKWorker.DoWork, AddressOf BKWorker_Do
        AddHandler BKWorker.ProgressChanged, Add开发者_运维技巧ressOf BKWorker_Progress
        AddHandler BKWorker.RunWorkerCompleted, AddressOf BKWorker_Completed
        BKWorker.RunWorkerAsync()

        'GetStructure(Path, "0", Diskname)
    End Sub

    Private Sub BKWorker_Do(ByVal sender As Object, ByVal e As DoWorkEventArgs)
        'Throw New NotImplementedException
        GetStructure(Path, "0", Diskname)
    End Sub

    Private Sub BKWorker_Progress(ByVal sender As Object, ByVal e As ProgressChangedEventArgs)
        'Throw New NotImplementedException
        Label1.Content = "Processing: " + e.UserState.ToString()
        If ProgressBar1.Value = 100 Then
            ProgressBar1.Value = 0
        End If
        ProgressBar1.Value = ProgressBar1.Value + 1
    End Sub

    Private Sub BKWorker_Completed(ByVal sender As Object, ByVal e As RunWorkerCompletedEventArgs)
        'Throw New NotImplementedException
        MessageBox.Show("Completed")
        Me.Close()
    End Sub
End Class

However the problem is that, the background thread is able to read files very fast, but the UI thread is not able to keep up the speed with it, could you please advice me on how I can solve this issue.


You almost never want to report progress on every single item when you're iterating through that many items.

I would suggest finding some reasonable number of files to wait for before reporting progress. Every 5th or every 10th or so on. You probably want to take a look at what your normal number of files is. In other words, if you're normally processing only 25 files, you probably don't want to only update every 10 files. But if you're normally processing 25000 files, you could maybe even only update every 100 files.


One quick answer would be to only report the progress when a certain amount of time has passed that way if 10 files were processed in that time the UI isn't trying to update one each one. If things are processing that fast then you really don't need to update the user on every single file.

Also on a quick side note if your ProgressBar isn't actually reporting progress from 0 to 100% you might want to just set its IsIndeterminate property to true instead of increasing the percent and then resetting it back to 0.

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