在后台线程中，从文件一行行异步加载内容进RichTextBox

XAML文件

XAML文件Code

<Grid>
    <!--一个RichTextBox读取文件中的内容-->
    <RichTextBox x:Name="LoadFileBox" Visibility="Collapsed"></RichTextBox>
    <TextBlock x:Name="CountBox" Text="" HorizontalAlignment="Center" VerticalAlignment="Center" FontSize="60"/>
    <TextBlock x:Name="TotalBox" HorizontalAlignment="Center" VerticalAlignment="Top" FontSize="30"/>
</Grid>

C#代码

C#代码

        public MainWindow()
        {
            InitializeComponent();
            ComputeTotal();
            Task.Factory.StartNew(() =>
            {//开辟一个后台线程
                LoadFileAsync();
            });
            
        }
        /// <summary>
        /// 计算总行数
        /// </summary>
        private void ComputeTotal()
        {
            int count = 0;
            using (var fs = new FileStream(@"D:\work\记事本项目WPF\1.txt", FileMode.Open))
            using (var reader = new StreamReader(fs))
            {
                while (reader.Peek() > 0)
                {
                    string line = reader.ReadLine();//异步读
                    if (line != null)
                    {
                        count++;
                    }
                }
                TotalBox.Text = "总数：" + count;
            }
        }
        /// <summary>
        /// 异步加载文件内容到RichTextBox
        /// </summary>
        async void LoadFileAsync()
        {
            int count = 0;
            using (var fs = new FileStream(@"D:\work\记事本项目WPF\1.txt", FileMode.Open))
            using (var reader = new StreamReader(fs))
            {
                while (reader.Peek() > 0)
                {
                    string line = await reader.ReadLineAsync();//异步读
                    if (line != null)
                    {
                        Dispatcher.Invoke(new Action(() =>
                        {
                            count++;
                            CountBox.Text = "当前解析到: " + count;
                            LoadFileBox.Document.Blocks.Add(new Paragraph(new Run(line)));
                        }));
                    }
                }
            }
            Dispatcher.Invoke(() =>
            {
                CountBox.Visibility = Visibility.Collapsed;
                TotalBox.Visibility = Visibility.Collapsed;
                LoadFileBox.Visibility = Visibility.Visible;
            });
        }