您可以返回一个任务，它会在流可用时立即提供给您。这是一个简化的解决方案，但却是一个很好的起点。是线程安全的。

private async Task<Stream> GetStreamAsync()
{
    try
    {
        return new FileStream("sample.mp3", FileMode.Open, FileAccess.Write);
    }
    catch (IOException)
    {
        await Task.Delay(TimeSpan.FromSeconds(1));
        return await GetStreamAsync();
    }
}

你可以像往常一样使用这个流:

using (var stream = await FileStreamGetter.GetStreamAsync())
{
    Console.WriteLine(stream.Length);
}

retry_possibility:
//somecode here

try
{
    using(FileStream stream = file.Open(FileMode.Open, FileAccess.Read, FileShare.None))
    {
        stream.Close();
    }
    //write or open your file here
}
catch (IOException)
{
    DialogResult dialogResult = MessageBox.Show("This file is opened by you or another user. Please close it and press retry.\n"+ expFilePath, "File Locked", MessageBoxButtons.RetryCancel);
    if (dialogResult == DialogResult.Retry)
    {
        goto retry_possibility;
    }
    else if (dialogResult == DialogResult.Cancel)
    {
        //do nothing
    }
}

下面是一些代码，据我所知，它与接受的答案相同，但代码更少:

    public static bool IsFileLocked(string file)
    {
        try
        {
            using (var stream = File.OpenRead(file))
                return false;
        }
        catch (IOException)
        {
            return true;
        }        
    }

然而，我认为用以下方式来做会更稳健:

    public static void TryToDoWithFileStream(string file, Action<FileStream> action, 
        int count, int msecTimeOut)
    {
        FileStream stream = null;
        for (var i = 0; i < count; ++i)
        {
            try
            {
                stream = File.OpenRead(file);
                break;
            }
            catch (IOException)
            {
                Thread.Sleep(msecTimeOut);
            }
        }
        action(stream);
    }

这样的东西会有用吗?

var fileWasWrittenSuccessfully = false;
while (fileWasWrittenSuccessfully == false)
{
    try
    {
        lock (new Object())
        {
            using (StreamWriter streamWriter = new StreamWriter("filepath.txt"), true))
            {
                streamWriter.WriteLine("text");
            }
        }

        fileWasWrittenSuccessfully = true;
    }
    catch (Exception)
    {

    }
}

static bool FileInUse(string path)
    {
        try
        {
            using (FileStream fs = new FileStream(path, FileMode.OpenOrCreate))
            {
                fs.CanWrite
            }
            return false;
        }
        catch (IOException ex)
        {
            return true;
        }
    }

string filePath = "C:\\Documents And Settings\\yourfilename";
bool isFileInUse;

isFileInUse = FileInUse(filePath);

// Then you can do some checking
if (isFileInUse)
   Console.WriteLine("File is in use");
else
   Console.WriteLine("File is not in use");

希望这能有所帮助!

我最近遇到了这个问题，找到了这个:https://learn.microsoft.com/en-us/dotnet/standard/io/handling-io-errors。

在这里，微软描述了以下检查IOException是否由于锁定文件导致的方法:

catch (IOException e) when ((e.HResult & 0x0000FFFF) == 32 ) {
    Console.WriteLine("There is a sharing violation.");
}