WPF progress bar update with dispatcher

I am trying to update a progressbar using the dispatcher but somehow cannot think where to place the dispatcher.Invoke and what to pass inside it.

Im trying to import files and needs to show the user how many files are imported using the progress bar.

so I have a delegate:

public delegate void DelegateA(ProgressClass progressClass);

im calling the delegate and passing the function to call.

DelegateA(FunctionA);

so while importing each file it calls the FunctionA.

private void FunctionA(ProgressClass progressClass)
{
    **//Put dispatcher.invoke here?**
    progressbar.updateprogress(progressclass);
    progressbar.show();
}

The progressclass has two properties which sets the progressbar's value(how many have been processed) and total items to process.

I can't understand what delegate method to pass in InvokeMethod(THreadPriority, delegate method)?

Sorry, if something is not clear.

回答1:

If you are trying to update the UI from some non-UI thread you can do something like this..

//here progress bar is a UIElement
progressBar.Dispatcher.BeginInvoke(
           System.Windows.Threading.DispatcherPriority.Normal
           , new DispatcherOperationCallback(delegate
                   {
                       progressBar1.Value = progressBar1.Value + 1;
                       //do what you need to do on UI Thread
                       return null;
                   }), null);

This code is taken from a good post about updating UI from background thread

回答2:

I am assuming that you've started a background thread to import the files. You should consider using BackgroundWorker for this, which is lightweight and has a mechanism built in to report progress (e.g., a ProgressBar) using an event.

If you want to use a new thread, anywhere within the processing that you are doing, just declare a delegate, add a function to target, and call Dispatcher.BeginInvoke:

Dispatcher.BeginInvoke(DispatcherPriority.Normal, new UpdateProgressDelegate(UpdateProgress), myProgressData);

//...

private delegate void UpdateProgressDelegate(ProgressClass progressClass);

void UpdateProgress(ProgressClass progressClass)
{
    progressbar.updateprogress(progressclass);
    progressbar.show(); 
}

回答3:

Here is the code for CSV reader with progress bar

private void InsertCSVRecords(DataTable csvdt) {

        connection();
        //creating object of SqlBulkCopy    
        SqlBulkCopy objbulk = new SqlBulkCopy(con);
        //assigning Destination table name    
        objbulk.DestinationTableName = "membershipsample";
        //Mapping Table column    
        objbulk.ColumnMappings.Add("GPO_NAME", "GPO_NAME");
        objbulk.ColumnMappings.Add("Ship_To", "Ship_To");
        objbulk.ColumnMappings.Add("Location_Type", "Location_Type");
        objbulk.ColumnMappings.Add("Bill_To", "Bill_To");
        objbulk.ColumnMappings.Add("GPO_CUST_ID", "GPO_CUST_ID");
        objbulk.ColumnMappings.Add("PRI_AFL_FLG", "PRI_AFL_FLG");
        objbulk.ColumnMappings.Add("MCK_GPO_PGM_TYPE", "MCK_GPO_PGM_TYPE");
        objbulk.ColumnMappings.Add("MCK_GPO_PGM_SUB_TYPE", "MCK_GPO_PGM_SUB_TYPE");
        objbulk.ColumnMappings.Add("MCK_MBRSH_EFF_DT", "MCK_MBRSH_EFF_DT");
        objbulk.ColumnMappings.Add("CUST_MAILING_NAME", "CUST_MAILING_NAME");
        objbulk.ColumnMappings.Add("ADDRESS1", "ADDRESS1");
        objbulk.ColumnMappings.Add("ADDRESS2", "ADDRESS2");
        objbulk.ColumnMappings.Add("CITY", "CITY");
        objbulk.ColumnMappings.Add("STATES", "STATES");
        objbulk.ColumnMappings.Add("POSTAL_CODE", "POSTAL_CODE");
        objbulk.ColumnMappings.Add("ACCT_MGR_NAME", "ACCT_MGR_NAME");

        con.Open();
        objbulk.WriteToServer(csvdt);
        con.Close();


    }

    private void button_Click(object sender, RoutedEventArgs e)
    {


        Microsoft.Win32.OpenFileDialog dlg = new Microsoft.Win32.OpenFileDialog();



        // Set filter for file extension and default file extension 
        dlg.DefaultExt = ".csv";
        dlg.Filter = "CSV Files (*.cvs)|*.csv|Excel Files (*.xlsx)|*.xlsx";

        // dlg.Filter = "JPEG Files (*.jpeg)|*.jpeg|PNG Files (*.png)|*.png|JPG Files (*.jpg)|*.jpg|GIF Files (*.gif)|*.gif";
        //dlg.Filter = "CSV Files (*.csv)";

        // Display OpenFileDialog by calling ShowDialog method 
        Nullable<bool> result = dlg.ShowDialog();


        // Get the selected file name and display in a TextBox 
        if (result == true)
        {
            // Open document 
            string filename = dlg.FileName;
            textBox.Text = filename;
            // readCSV(filename);
        }


    }
    private void readCSV(string Path)
    {
        using (var reader = new StreamReader(Path))
        {
            List<string> listA = new List<string>();
            List<string> listB = new List<string>();
            while (!reader.EndOfStream)
            {
                var line = reader.ReadLine();
                var values = line.Split(';');

                if (!String.IsNullOrEmpty(values[0]))
                    listA.Add(values[0]);
                if (values.Length > 2 && !String.IsNullOrEmpty(values[1]))
                    listB.Add(values[1]);
            }
        }

    }

    private void Bk_DoWork(object sender, DoWorkEventArgs e)
    {


        // txtStatus.Visibility = System.Windows.Visibility.Visible;
        DispatcherTimer timer = new DispatcherTimer();
        //Creating object of datatable  
        DataTable tblcsv = new DataTable();
        //creating columns  
        tblcsv.Columns.Add("GPO_NAME");
        tblcsv.Columns.Add("Ship_To");
        tblcsv.Columns.Add("Location_Type");
        tblcsv.Columns.Add("Bill_To");
        tblcsv.Columns.Add("GPO_CUST_ID");
        tblcsv.Columns.Add("PRI_AFL_FLG");
        tblcsv.Columns.Add("MCK_GPO_PGM_TYPE");
        tblcsv.Columns.Add("MCK_GPO_PGM_SUB_TYPE");
        tblcsv.Columns.Add("MCK_MBRSH_EFF_DT");
        tblcsv.Columns.Add("CUST_MAILING_NAME");
        tblcsv.Columns.Add("ADDRESS1");
        tblcsv.Columns.Add("ADDRESS2");
        tblcsv.Columns.Add("CITY");
        tblcsv.Columns.Add("STATES");
        tblcsv.Columns.Add("POSTAL_CODE");
        tblcsv.Columns.Add("ACCT_MGR_NAME");

        // DispatcherTimer timer = new DispatcherTimer();
        string url=string.Empty;
        this.Dispatcher.Invoke(() => { url = textBox.Text; });
        string ReadCSV = File.ReadAllText(url);
        //spliting row after new line  url
        int i = 0;
        DataTable dt = GetMemberTable();
        var worker = sender as BackgroundWorker;
        int rows = ReadCSV.Split('\n').Length / 100;
        int totalRows = ReadCSV.Split('\n').Length;
        foreach (string csvRow in ReadCSV.Split('\n'))
        {

            i++;
           // Thread.Sleep(1000);
                   worker.ReportProgress((i/rows + 1), string.Format("This is new one"));
            this.Dispatcher.Invoke(() => { label.Content = i + " rows have been added or updated"; });
            bool Check = (csvRow.Length > 0) ? Exist(csvRow.Split(',')[1].ToString(), dt) : true;
            if (i > 1 && !string.IsNullOrEmpty(csvRow))
            {
                //Adding each row into datatable  

                int count = 0;
                if (!Check)
                {
                    tblcsv.Rows.Add();
                    foreach (string FileRec in csvRow.Split(','))
                    {

                        if (count >= 15)
                        {
                            tblcsv.Rows[tblcsv.Rows.Count - 1][count] = FileRec;
                        }
                        else
                        {
                            tblcsv.Rows[tblcsv.Rows.Count - 1][count] = FileRec;
                            count++;
                        }
                        //                  //Calling insert Functions 
                        //                  Dispatcher.Invoke(
                        //new System.Action(() => downloadProgress.Value = i)
                        //);


                    }

                }


            }


        }
        if (tblcsv.Rows.Count > 0)
        {
            InsertCSVRecords(tblcsv);
        }
        worker.ReportProgress(100, "Done");
        this.Dispatcher.Invoke(() => { textBox.Text = string.Empty; });
        //textBox.Text = string.Empty;
        this.Dispatcher.Invoke(()=> { label.Content = totalRows + " rows have been added or updated"; });
        this.Dispatcher.Invoke(() => { button1.IsEnabled = false; });
        //button1.IsEnabled = false;
    }
    private void button1_Click(object sender, RoutedEventArgs e)
    {
        BackgroundWorker bk = new BackgroundWorker();
        bk.RunWorkerCompleted += Bk_RunWorkerCompleted;
        bk.WorkerReportsProgress = true;
        bk.DoWork += Bk_DoWork;
        bk.ProgressChanged += Bk_ProgressChanged;
        bk.RunWorkerAsync();


    }

    private void Bk_ProgressChanged(object sender, ProgressChangedEventArgs e)
    {
        this.Dispatcher.Invoke(() => { downloadProgress.Value = e.ProgressPercentage; });
        //downloadProgress.Value = e.ProgressPercentage;
    }

    //private void Bk_DoWork(object sender, DoWorkEventArgs e)
    //{
    //    AddData();
    //    var worker = sender as BackgroundWorker;
    //    worker.ReportProgress(0, string.Format("This is new one"));
    //    for(int i=0;i<10;i++)
    //    {
    //        Thread.Sleep(1000);
    //        worker.ReportProgress((i + 1) * 10, string.Format("This is new one"));
    //    }

    //    worker.ReportProgress(100, "Done");

    //}

    private void Bk_RunWorkerCompleted(object sender, RunWorkerCompletedEventArgs e)
    {
        MessageBox.Show("All Done");
        this.Dispatcher.Invoke(() => { downloadProgress.Value = 0; });
    }