C# printing with WPF

Question

My application prints (to a printer) the information shown on screen (using the Canvas control) N times.

The process is

The user clicks a button (called Pri

Answer 1

Your UpdateText method is all wrong. Each time you call the method you are creating a new string in the textblock. So as a result all you will see is the last call to the routine.

Instead you should be appending to the text instead of replacing the text.

Answer 2

The answer (sorry the code is not exactly the same as the question but it's so simple it should be easy to follow. Thank you every one.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using System.Windows.Threading;


namespace WpfApplication1
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();
        }

        private void Button_Click(object sender, RoutedEventArgs e)
        {
            for (int i = 0; i < 2; i++)
            {
            result res = null;     
            if (i == 0)
            res = new result { Comments = "First Time Round" };

            if (i == 1)
                res = new result { Comments = "Total hard type" };

            Dispatcher.Invoke(DispatcherPriority.Loaded, new Action(delegate
                {   
                    this.DataContext = res;
                }
            ));

            System.Threading.Thread.Sleep(500);

            Dispatcher.Invoke(DispatcherPriority.Loaded, new Action(delegate
            {
                PrintDialog dialog = new PrintDialog();
                dialog.PrintVisual(this.canvas1, "");
            }
        ));
            System.Threading.Thread.Sleep(500);

            }
        }
    }

    class result
    {
        public string Comments { get; set; }
    }
}

Answer 3

Use PrintDialog dialog = new PrintDialog(); inside for loop Use this function

 private void button1_Click(object sender, RoutedEventArgs e)
    {

        for (int i = 1; i < 3; i++)
        {
           PrintDialog dialog = new PrintDialog();
            //showing this message box fixes the issue
            //MessageBox.Show("01");
            updateTextblock(i);

            //use the dispatcher object to ensure all renders and databinding are completed before sending to print   
            Dispatcher.BeginInvoke(DispatcherPriority.Loaded, new Action(delegate
            {
                print(dialog);
            }
            ));   
        }
    }

Answer 4

The BeginInvoke returns a DispatcherOperation. If you call Wait on it before continuing in the for loop, the textbox will not be updated, until the first print has been performed.