Question

当我的程序读取行File.Delete("upv/version.txt");时出现此错误，但我不知道问题出在哪里以及如何解决问题。有人能帮助我吗？

System.IO.IOException：＆＃39;进程无法访问该文件＆＃39; C：\用户\ XXX \源\回购\ WpfApp1 \ WpfApp1 \ BIN \调试\ UPV \ version.txt＆＃39; 因为它正被另一个进程使用。＆＃39;

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
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.Net;
using System.IO;
using System.ComponentModel;

namespace WpfApp1
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window
    {
        public MainWindow()
        {
            InitializeComponent();

            btnPlay.IsEnabled = false; 

            if (VerifyVersion())
                btnPlay.IsEnabled = true;
            else

                Download("http://localhost/","text.rar"); 

        }

        private void btnPlay_Click(object sender, RoutedEventArgs e)
        {
            System.Diagnostics.Process.Start("Game.exe");
        }

        private void ProgressBar_ValueChanged(object sender, RoutedPropertyChangedEventArgs<double> e)
        {

        }

        private string VersionActuelle;

                private bool VerifyVersion()
        {
            StreamReader VersionReader = new StreamReader("upv/version.txt");
            string VersionClient = VersionReader.ReadToEnd();

            VersionClient = VersionClient.Replace(System.Environment.NewLine, string.Empty);

            VersionActuelle = ReadRemoteTextFile("http://localhost/upv/version.txt");

            VersionActuelle = VersionActuelle.Replace(System.Environment.NewLine, string.Empty);

            if (VersionActuelle == VersionClient)
                return true;
            else
                return false;
        }

        private string ReadRemoteTextFile(string Url)
        {
            Uri uri = new Uri(Url); 

            WebRequest wRequest = WebRequest.Create(uri); 

            WebResponse wResponse = wRequest.GetResponse(); 

            Stream ResponseStream = wResponse.GetResponseStream(); 

            StreamReader sReader = new StreamReader(ResponseStream); 

            string Temp = sReader.ReadToEnd();

            return Temp;
        }

        private void Download(string Url, string DownloadTo)
        {
            WebClient wClient = new WebClient(); 


            wClient.DownloadProgressChanged += new DownloadProgressChangedEventHandler(UpdateProgressChange);  


            wClient.DownloadFileCompleted += new System.ComponentModel.AsyncCompletedEventHandler(UpdateDone); 


            wClient.DownloadFileAsync(new Uri(Url), DownloadTo); 


        }

        private void UpdateProgressChange(object sender, DownloadProgressChangedEventArgs e)
        {
            progressBar.Value = e.ProgressPercentage; 
        }

        private void UpdateDone(object sender, System.ComponentModel.AsyncCompletedEventArgs e)
        {
            //MessageBox.Show("Mise à jour terminée! Vous pouvez désormais jouer.", "Notification");
            btnPlay.IsEnabled = true;

            File.Delete("upv/version.txt");

            using(System.IO.TextWriter sWriter = File.CreateText("upv/version.txt"))
            {
                sWriter.Write(VersionActuelle);
            }
        }
    }
}

Answer 1

当你在VerifyVersion方法中读取文件时，你需要处理文件..你需要放一个VersionReader.Close（）; o如果使用Using子句来处置文件，那就更好了。

Answer 2

每当您使用 StreamReader 或 StreamWriter 时，请调用 Dispose 关闭该特定实例，但您不会发现错误发生试。

在你的情况下，

string VersionClient = VersionReader.ReadToEnd();
VersionReader.Dispose();

并且

StreamReader sReader = new StreamReader(ResponseStream); 
string Temp = sReader.ReadToEnd();
sReader.Dispose();

修改：在使用使用时，您不需要关闭StreamWriter实例，因为它会自动刷新

该进程无法访问该文件

2 个答案: