C#system.io IOException“文件无法访问，因为它被另一个进程访问”[重复]

Question

我刚使用System.io，我不明白为什么我的代码会导致这个异常。我想检查一个目录和一个文件是否存在，如果不存在，我想创建它们。之后，我想在我刚创建的文件上写点东西。在这里它抛出异常。我非常确信，当im试图使用StreamWriter时，创建会导致异常，因为如果该文件已经存在，我不会得到一个执行。此外，当我在一次尝试失败后再次单击调用此funktion的按钮时，没有任何例外，并且一切都运行良好（看起来我的程序在刷新UI后意识到没有打开的进程）。我不明白，似乎还有什么其他进程在访问该文件，我认为在使用fileinfo.create（）funktion之后，我不需要关闭任何流。

public static void Save_map(int[,] p_temp_map_property, string p_filename)
    {
        temp_map_property = p_temp_map_property;
        try
        {
            DirectoryInfo MapsDirectory = new DirectoryInfo("Maps");
            DirectoryInfo Map = new DirectoryInfo(@"Maps\" + p_filename);
            FileInfo file = new FileInfo(@"Maps\" + p_filename + @"\" + p_filename + ".txt");
            if (!MapsDirectory.Exists)
            {
                MapsDirectory.Create();
            }

            if (!Map.Exists)
            {
                Map.Create();
            }

            if (!file.Exists)
            {
                file.Create();
            }

            StreamWriter sw = new StreamWriter(@"Maps\" + p_filename + @"\" + p_filename + ".txt", false);
            
            for(int n = 0; n < 140; n++)
            {
                for(int m = 0; m < 90; m++)
                {
                    sw.WriteLine(p_temp_map_property[n, m]);
                }
            }
            sw.Close();
            sw.Dispose();
            MessageBox.Show("Map saved successfully!");
        }
        catch(Exception e)
        {
            MessageBox.Show(e.ToString());
        }
    }

Exception thrown: "System.IO.IOException" in mscorlib.dll
System.IO.IOException: The procces cannot acsses "C:\Users\User\source\repos\Map Editor TD\Map Editor TD\bin\Debug\Maps\test\test.txt" because it is accsessed in another process.
   at System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath)
   at System.IO.FileStream.Init(String path, FileMode mode, FileAccess access, Int32 rights, Boolean useRights, FileShare share, Int32 bufferSize, FileOptions options, SECURITY_ATTRIBUTES secAttrs, String msgPath, Boolean bFromProxy, Boolean useLongPath, Boolean checkHost)
   at System.IO.FileStream..ctor(String path, FileMode mode, FileAccess access, FileShare share, Int32 bufferSize, FileOptions options, String msgPath, Boolean bFromProxy, Boolean useLongPath, Boolean checkHost)
   at System.IO.StreamWriter.CreateFile(String path, Boolean append, Boolean checkHost)
   at System.IO.StreamWriter..ctor(String path, Boolean append, Encoding encoding, Int32 bufferSize, Boolean checkHost)
   at System.IO.StreamWriter..ctor(String path, Boolean append)
   at Map_Editor_TD.Save_to_File.Save_map(Int32[,] p_temp_map_property, String p_filename) in C:\Users\User\source\repos\Map Editor TD\Map Editor TD\Save_to_File.cs:Zeile 39.

我希望有比我更有经验的人能帮我。提前道谢。

Answer 1

file.create()；使文件保持打开状态，并返回句柄。要么先关闭它，要么用它向它写东西。

下面的代码使用它：

public static void Save_map(int[,] p_temp_map_property, string p_filename)
{
    temp_map_property = p_temp_map_property;
    try
    {
        DirectoryInfo MapsDirectory = new DirectoryInfo("Maps");
        DirectoryInfo Map = new DirectoryInfo(@"Maps\" + p_filename);
        FileInfo file = new FileInfo(@"Maps\" + p_filename + @"\" + p_filename + ".txt");
        if (!MapsDirectory.Exists)
        {
            MapsDirectory.Create();
        }

        if (!Map.Exists)
        {
            Map.Create();
        }

        using (FileStream fileStream = file.Exists ? file.OpenWrite() : file.Create())
        using (StreamWriter sw = new StreamWriter(fileStream, false))
        {
            for (int n = 0; n < 140; n++)
            {
                for (int m = 0; m < 90; m++)
                {
                    sw.WriteLine(p_temp_map_property[n, m]);
                }
            }
        }
        
        MessageBox.Show("Map saved successfully!");
    }
    catch(Exception e)
    {
        MessageBox.Show(e.ToString());
    }
}