Progressbar在阅读流时不工作

Question

我已经看到很多关于进度条和多线程的问题和帖子，所以我希望我不要问一个其他地方已经回答的问题。但如果我这样做，我的应用，我试图找到一个解决方案。

我有一些大的文件，我想通过&更换&由于这些文件比较大，我想忒看到statusupdate飘飞文档多远解析。我编写的代码用于替换＆符号，但是，只有在文档解析完成后才能完成进度更新。任何想法有什么不对？

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) 
     { 
     } 
    } 
} 

Answer 1

您也在筹集太多活动。你不应该为每一行解析出一个事件。这将填满Windows消息队列，并且不能跟上。每次你有一些重大进展时（例如每完成1％提高一个事件），每次只举一个事件。

另外，ReportProgress的第一个参数应该是介于0到100之间的百分比，表示工作的完成程度。您在这里滥用它返回一个行号：

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

而且，这也是值得一提的是您目前正在吞噬你的代码可以生成任何异常。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. 
    } 
}