读取流时进度条不工作

本文关键字：工作 读取 | 更新日期: 2023-09-27 18:04:37

我已经看到了很多关于进度条和多线程的问题和帖子，所以我希望我没有问一个在其他地方已经回答的问题。但是，如果我做了，我的道歉，我试图找到一个解决方案。

我有一些大文件，我想替换&由,因为这些文件很大，所以我希望不时看到状态更新，看看文档已经解析了多少。我所编写的代码用于替换&号，但是，只有在文档被解析后才会进行进度更新。知道怎么回事吗?

using System;
using System.Windows;
using Microsoft.Win32;
using System.Text;
using System.Xml;
using System.IO;
using System.Diagnostics;
using System.Data.SqlClient;
using System.Data;
using System.Text.RegularExpressions;
using System.ComponentModel;
namespace DigiPort
{
    public partial class MainWindow : Window
    {
        public string filename;
        public string xmlfilename;
        BackgroundWorker worker = new BackgroundWorker();
        public MainWindow()
        {
            InitializeComponent();
        }
        private void onImportDocClicked(object sender, RoutedEventArgs e)
        {
            OpenFileDialog ofd = new OpenFileDialog();
            ofd.Filter = "Text documents (.txt)|*.txt";
            Nullable<bool> result = ofd.ShowDialog();
            if (result == true)
            {
                OutPutWindow.Text = "Document wordt nu gelezen.";
                filename = ofd.FileName;
                worker.DoWork += new DoWorkEventHandler(ReplaceAmpersandAsync);
                worker.ProgressChanged += new ProgressChangedEventHandler(ProBarChanged);
                worker.RunWorkerCompleted += new RunWorkerCompletedEventHandler(ReplaceAmpersandCompleted);
                worker.WorkerReportsProgress = true;
                worker.ReportProgress(0, "Start counting lines");
                int count = ReadNumberOfLines();
                worker.ReportProgress(0, "Lines counted. Total number of lines is: " + count);
                worker.RunWorkerAsync(count);
                OutPutWindow.Text = "Document gelezen en ampersands vervangen.";
            }
        }
        private int ReadNumberOfLines()
        {
            int count = 0;
            using (FileStream fs = File.Open(filename, FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
            using (BufferedStream bs = new BufferedStream(fs))
            using (StreamReader sr = new StreamReader(bs))
                while (!sr.EndOfStream)
                {
                    sr.ReadLine();
                    count++;
                }
            return count;
        }
        private void ReplaceAmpersandAsync(object sender, DoWorkEventArgs e)
        {
            int i = 0;
            int count = (int)e.Argument;
            xmlfilename = filename + ".xml";
            StreamWriter writer = new StreamWriter(xmlfilename);
            using (FileStream fs = File.Open(filename, FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
            using (BufferedStream bs = new BufferedStream(fs))
            using (StreamReader sr = new StreamReader(bs))
            while (!sr.EndOfStream)
            {
                double percentage = (i++ * 100) / count;
                worker.ReportProgress((int)Math.Round(percentage, 0));
                if (i % 100000 == 0)
                {
                    worker.ReportProgress(i, "Linenumber " + i + " is now parsed");
                }
                string content = sr.ReadLine();
                writer.WriteLine(content.Replace("&", "&amp;"));
            }
            writer.Close();
            worker.ReportProgress(i, "All lines are parsed, file is saved");
        }
        private void ProBarChanged(object sender, ProgressChangedEventArgs e)
        {
            ProBar.Value = e.ProgressPercentage;
            OutPutWindow.Text += (string)e.UserState;
        }
        private void ReplaceAmpersandCompleted(object sender, RunWorkerCompletedEventArgs e)
        {
        }
    }
}

读取流时进度条不工作

您也引发了太多事件。不应该为解析的每一行都引发事件。这将填满windows消息队列，它将无法跟上。只有当你有一些重要的进展时才触发一个事件(例如，每完成1%就触发一个事件)。

ReportProgress的第一个参数应该是一个介于0到100之间的百分比，表示工作的完成程度。您在这里错误地使用它来返回行号:

worker.ReportProgress(i, "Linenumber " + i + " is now parsed");

值得一提的是，您当前正在消化代码可能生成的任何异常。在完成的事件处理程序中，您应该检查是否有错误:

private void ReplaceAmpersandCompleted(object sender, RunWorkerCompletedEventArgs e)
{
    if (e.Error != null) {
        // Show the user an error message.
    }
}
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